Diuretics

What Kind of Drug Is It?

The main goal of diuretic therapy is to get rid of extra fluids in the body. Diuretics reduce bodily fluids by increasing the production of urine. Diuretic drugs are used to treat high blood pressure, congestive heart failure (CHF), and various other conditions that cause the body to retain, or hold in, water. CHF occurs when the heart is unable to circulate, or pump, the blood throughout the body with sufficient force.

Overview

Diuretics are a class of drugs that increase urine output. That means that users not only urinate more often, they urinate in greater amounts than usual. The main medical uses for diuretics are the treatment of high blood pressure and congestive heart failure.

Because diuretics cause an overall water weight loss, they are often abused by individuals with eating disorders such as anorexia (pronounced ah-nuh-REK-see-uh) and bulimia (pronounced bull-EEM-eeh-yuh). Anorexia is a severe disorder characterized by an intense fear of gaining weight, a refusal to eat, a distorted sense of self-image, and excessive weight loss. Bulimia is a disorder that involves long periods of bingeing on food, followed by self-induced vomiting and abuse of laxatives. The words anorexia and bulimia are both taken from the Greek language. Anorexia means "no appetite" and bulimia means "great hunger."

Official Drug Name: The three main groups of diuretics (die-er-EH-tiks) discussed in this entry are: 1) the loop diuretics, 2) the potassium-sparing diuretics, and 3) the thiazide (THY-uhzide) diuretics. Loop diuretics include bumetanide (byoo-MEH-tuh-nide; Bumex), furosemide (fur-OH-seh-mide; Lasix), and torsemide (TORE-seh-mide; Demadex). Potassium-sparing diuretics include amiloride hydrochloride (am-ILL-ohr-ide high-droh-KLOR-ide; Midamor), spironolactone (speer-oh-noh-LACK-tone; Aldactone), and triamterene (try-AM-tuh-reen; Dyrenium). Thiazide (and thiazide-like) diuretics include chlorothiazide (KLOR-oh-THY-uh-zide; Diurigen, Diuril), chlorthalidone (klor-THAL-ih-doan; Hygroton, Thalitone), hydrochlorothiazide (HIGH-droh-KLOR-oh-THY-uh-zide; Dichlotride, Esidrix, Ezide, Hydrochlor, Hydro-D, Hydro-DIURIL, Hydro-Par, and Microzide), indapamide (inn-DAH-puh-mide; Lozol), and metolazone (meh-TOE-luh-zone; Diulo, Mykrox, Zaroxolyn).

Also Known As: Water pills

Drug Classifications: Not scheduled

Diuretics are also abused by athletes who are trying to "make weight" for certain classes of competition. Oftentimes, the use of diuretics can help athletes, such as weightlifters, lose just enough—perhaps an extra pound or so—to remain in their chosen weight class. This practice is illegal in sporting competition, however. Diuretics are considered banned substances according to the International Olympic Committee (IOC), the United States Anti-Doping Agency (USADA), the World Anti-Doping Agency (WADA), the National Collegiate Athletic Association (NCAA), and a number of other national and international sporting authorities.

William Withering's Work on Diuretics

The name diuretic comes from a Greek term meaning "to urinate." This type of drug first gained acceptance in the medical community when eighteenth-century British physician William Withering (1741–1799) created digitalis (dij-ih-TAL-us) from the dried leaves of the foxglove plant (Digitalis purpurea). Digitalis gives the heart muscle a boost, making its contractions stronger and faster.

Digitalis also acts as a diuretic. In With-ering's time, it became a popular treatment for dropsy (DROP-see), an old-fashioned term for edema. People with edema often have swollen feet, ankles, and lower legs due to water buildup in their tissues. Fluid retention in the tissues of the body can be very dangerous. It is frequently related to congestive heart failure, which can be deadly. As of 2005, digitalis-type drugs were still being used in the treatment of heart failure. By strengthening the contractions of the heart muscle, digitalis helps pump excess fluids throughout the body. When the heart works more efficiently, fluids are less likely to pool, or accumulate, in the feet and legs.

Breakthroughs in Diuretic Research

In 1957, researchers John Baer, Karl Beyer, James Sprague, and Frederick Novello formulated the drug chlorothiazide (KLOR-oh-THY-uh-zide), the first of the thiazide diuretics. It was a pioneering achievement in medicine. Chlorothiazide was the first safe and effective long-term treatment for patients with high blood pressure and heart failure. All four scientists received the Albert and Mary Lasker Foundation Special Public Health Award for 1975 for their work on diuretic drug compounds. According to the Lasker Foundation Web site, "Such compounds are now universally accepted as a primary treatment for these conditions."

The next class of diuretic drugs to be developed were the so-called "loop diuretics." They take their name from the fact that they work on a specific part of the kidney known as the loop of henle. Loop diuretics are the most powerful of all diuretics. The first one to appear on the market was furosemide (Lasix) in 1965. Loop diuretics were hailed as a major advance in the treatment of congestive heart failure.

It was around this time that over-the-counter diuretics first became available. Pamabrom (Pamprin), a medication that relieves the fluid retention and bloating associated with a woman's menstrual cycle, is still available without a prescription. There are also certain dietary supplements that may have diuretic action as a side effect, but have a different primary purpose. For example, the supplement creatine promotes fluid loss with regular use. (A separate entry on creatine is available in this encyclopedia.)

What Is It Made Of?

Diuretics are medicines with complex chemical structures. For example, the chemical formula for chlorothiazide, the best known of the thiazide diuretics, is C₇H₆ClN₃O₄S₂.

How Is It Taken?

Diuretics are most commonly available in pill form. In a hospital setting, they may be injected directly into a patient's veins. Certain diuretics used to control pressure on the eyeball may be administered in eye drop form. Some diuretics are consumed naturally in foods, including various fruits, vegetables, and herbs.

Are There Any Medical Reasons for Taking This Substance?

Diuretics are typically used to treat high blood pressure, congestive heart failure, edema, and other conditions that cause the body to retain excess fluids. In addition to their traditional uses, diuretics show promise in the treatment of several other

medical conditions, including osteoporosis, heart attack, and stroke.

Usage Trends

The 2004 edition of The Pill Book and the 2005 edition of the Nursing Spectrum Drug Handbook list the loop diuretic furosemide (Lasix) among the top ten most commonly prescribed drugs in the United States. Not far behind were the thiazide diuretic hydrochlorothiazide and the potassium-sparing diuretic triamterene, both of which landed in the top twenty.

Cheap but Effective Prescription Drugs

Lawrence K. Altman reported in the New York Times that "traditional water pills, or diuretics, are superior to newer, more expensive drugs in lowering high blood pressure and preventing its serious and often fatal complications." In 2002, a New Jersey-based study was conducted involving more than 42,000 men and women of varied ethnic backgrounds age fifty-five and older. The results showed that diuretics were found more effective in lowering the participants' blood pressure than the trendier—and extremely costly—new classes of blood pressure drugs. In follow-up reports published in 2005, researchers suggested that thiazide diuretics, in particular, are also helpful in preventing heart attacks and strokes.

In addition, several sources, including the 2003 Rotterdam Study, have shown that thiazide diuretics "may reduce bone loss by reducing the amount of calcium excreted in the urine," reported Eric Nagourney in the New York Times. Thiazide diuretics seem to protect the elderly against hip fractures, a common and potentially life-threatening ailment among older people. "The benefit was most pronounced in people over eighty," noted Nagourney.

Abusing Diuretics to Lose Weight

Although diuretics have legitimate uses, some people abuse the drugs. The most widespread abuses of diuretics appear among: 1) individuals suffering from eating disorders; and 2) athletes attempting to keep their weight down for sporting competitions.

According to the National Institute of Mental Health (NIMH), up to 3.7 percent of females suffer from anorexia, and up to 4.2 percent of females suffer from bulimia at some point in their lives. Anorexia involves self-starvation in an effort to keep off weight. Bulimia involves a cycle of bingeing and purging, meaning people eat massive amounts of food in a single sitting and then attempt to rid themselves of the huge caloric intake before it can be digested. Bulimics purge the food through self-induced vomiting, laxative use, and diuretics.

Males generally develop eating disorders less frequently than females. However, as of 2005, the percentage of males with eating disorders was on the rise. In addition, the National Eating Disorders Association (NEDA) reported that patients with either anorexia or bulimia frequently "develop the other eating disorder" within five to fifteen years of developing the first. In other words, a person with anorexia may end up with bulimia and a person with bulimia may end up with anorexia. This shift in disorders, according to NEDA president Doug Bunnell, helps "remind clinicians, patients, and families that these disorders are complicated."

Blood Pressure Facts

The following statistics were cited in reports on a study of diuretics funded by the National Heart, Lung and Blood Institute, the National Institute on Aging, and the Robert Wood Johnson Foundation.

• High blood pressure affects about 50 million people in the United States, and the risk increases with age.
• Half of all Americans over the age of sixty have high blood pressure.
• One-third of Americans over the age of sixty have both high blood pressure and diabetes, a serious disorder affecting the level of sugars in the blood.

The Sports Connection

Diuretic use and eating disorders in sports and professional athletics are growing concerns both in the United States and abroad. Jockeys, swimmers, and gymnasts, for instance, compete under conditions where "smaller" is considered "better." Weight loss among these and other athletes may be encouraged by coaches. Female athletes, in particular, often develop eating disorders and unhealthy weight-loss practices, including diuretic abuse. This puts them at a higher risk for osteoporosis and interrupting their menstrual cycle.

Sports such as weightlifting, wrestling, and boxing require regular weigh-ins. Diuretics are sometimes used by athletes to lose weight quickly in order to compete in lower-weight classes. The pressure to keep their weight down may extend beyond the use of diuretics, leading to starvation diets and attempts to sweat off pounds in rubber suits or saunas. These and other unsafe practices can put athletes at risk for severe dehydration, seizures, and even death.

Diuretics in the sports world have another documented use. Called "masking," it is when diuretics are used to speed the elimination of banned performance-enhancing substances from the body. This practice increases the users' chances of passing mandatory drug tests. Athletes using steroids, for instance, might attempt to rid their bodies of trace amounts of the banned drug by taking diuretics.

Many sports organizations have added diuretics and other masking agents to their list of banned substances. For example, the National Football League Players Association (NFLPA) mentions diuretic use in its steroid policy. The organization notes that "masking agents or diuretics used to hide [the presence of steroids and other performance-enhancing substances]" are considered "Prohibited Substances." Steroids, masking agents, diuretics, and other banned substances "have no legitimate place in professional football."

Effects on the Body

There are three main classes of diuretics: loop diuretics, potassium-sparing diuretics, and thiazide diuretics. The main function of diuretics is to increase the amount of sodium and fluids excreted by the kidneys.

Kidneys and Electrolytes

The kidneys are the urine-producing organs of the body. They act as filters for body fluids, sifting out waste products and keeping important body chemicals called electrolytes at steady levels. As the Kidney Learning System Web site points out, another key function of these "powerful chemical factories" is to "remove drugs from the body."

Sodium, potassium, chloride, calcium, and magnesium are all examples of electrolytes. These chemicals are present in the body's fluids and help move nutrients into cells and wastes out of them. Nerve, muscle, and heart functions depend on proper levels of electrolytes in the body. The use of diuretics, however, can trigger electrolyte imbalances. This occurs because diuretics increase the amount of urine the body releases. Sodium, potassium, and other electrolytes can be removed from the body along with the urine.

The kidneys work to keep electrolyte concentrations in the blood at an even level. However, swings in body fluid chemicals do occur. Improper levels of electrolytes can cause a variety of symptoms, including confusion, fainting, dizziness, and headache.

Reducing Fluid Levels

In general, diuretics work by encouraging the loss of sodium and fluid from the body. This is the key to their effectiveness in treating high blood pressure and congestive heart failure.

People who suffer from long-term high blood pressure are said to have hypertension. Hypertension occurs when the force of blood against the blood vessel walls increases. This condition may be treated with diuretics from all three classes. Those used most often include thiazides such as chlorothiazide and hydrochlorothiazide; the potassium-sparing diuretic spironolactone; and the loop diuretic furosemide. Diuretics relieve hypertension by flushing excess water and sodium from the body. Lower fluid levels decrease the pressure on blood vessels and help improve blood circulation, resulting in lower blood pressure.

Congestive heart failure occurs when the pumping ability of the heart is impaired. Loop diuretics such as furosemide are most frequently prescribed to reduce the edema that results from congestive heart failure. Thiazide and potassium-sparing diuretics may also be prescribed.

Doctors also prescribe diuretics for other conditions that cause fluid retention, including certain types of diabetes and various diseases of the kidneys and the liver. Water retention related to menstruation is usually relieved with over-the-counter diuretics containing Pamabrom (Pamprin).

Among the more common side effects of diuretic use are nausea, dizziness, skin rashes, sensitivity to sunlight, high blood sugar levels, and an inability to control urination. Less common side effects associated with diuretic use include hearing loss, lowered red blood cell or white blood cell levels, and inflammation of the pancreas, a gland vital to digestion.

The All-Important Kidney

Just how important are the kidneys? The National Kidney Foundation's Kidney Learning System Web site reveals some interesting facts about the kidneys and their function.

• Humans have two kidneys, one on either side of the spinal column near the middle of the back.
• The kidneys are shaped like beans. They get their name from the "kidney bean."
• On average, each kidney weighs about 5 ounces.
• The kidneys filter about 200 quarts of fluid in a 24-hour period.
• Of those 200 quarts of fluid, about 2 quarts are made into urine and excreted from the body.
• The other 198 quarts of fluid are "cleaned up" and returned to the bloodstream.
• Urine is usually stored in the bladder anywhere from one hour to eight hours before it is excreted.
• Diabetes and high blood pressure are the most common causes of kidney disease.
• Over-the-counter pain relievers taken in large doses or for more than several weeks at a time can cause serious damage to the kidneys.

The Loop Diuretics and Their Action on the Kidneys

Each kidney consists of about 1 million nephrons held in place by supporting tissue. Nephrons are the tiny filtering units of the kidney. These structures are responsible for moving fluids and waste out of the bloodstream, resulting in urine formation. Loop diuretics take their name from the part of the kidney upon which they work—the loop of Henle. The loop of Henle is a branch within each nephron where sodium and potassium are reabsorbed back into the bloodstream instead of being filtered into the urine. Loop diuretics inhibit this action and promote excretion of the sodium and potassium instead, along with calcium, magnesium, and, of course, water. Loop diuretics are considered the most powerful of all diuretics. Bumetanide (Bumex), furosemide (Lasix), and torsemide (Demadex) are all loop diuretics.

The Potassium Balancing Act and Other Things to Know about Diuretics

Two other classes of diuretics are the thiazides and the potassium-sparing diuretics. Thiazide diuretics such as chlorothiazide and hydrochlorothiazide work by blocking sodium reabsorption by the kidneys. They are "potassium-depleting" diuretics, meaning that they cause a loss of potassium from the body. This condition is known as hypokalemia. This loss may be reversed by eating potassium-rich foods, such as bananas, or by taking potassium supplements. Signs of hypokalemia include a rapid or irregular heartbeat, fatigue, weakness, mood swings, muscle cramps, nausea, vomiting, a dry mouth, and persistent thirst.

The diuretics amiloride, spironolactone, and triamterene are known as "potassiumsparing" diuretics. This type of diuretic is used commonly in the treatment of congestive heart failure. Their use may cause hyperka lemia, a condition where there is too much potassium in the body. Signs of hyperkalemia include an irregular heartbeat, tiredness, weakness, difficulty breathing, numbness, a tingling sensation in the hands or feet, anxiety, and difficulty concentrating.

Sometimes, potassium-sparing diuretics are used in conjunction with thiazide diuretics to keep potassium levels in the user's body stable. One drug known by the brand name Dyazide is a good example of a combination-type diuretic. It contains hydrochlorothiazide (a thiazide diuretic that causes a loss of potassium in the body) and triamterene (a diuretic that helps the body retain potassium).

Other Risks:

The use of diuretics can be especially risky among pregnant women, people with compromised immune systems, and individuals with certain drug allergies. Physicians must be made aware of a patient's complete medical history before they can prescribe diuretics safely. Individuals who take diuretics for more than six months at a time run the risk of developing chemical imbalances that can result in serious side effects.

Natural Diuretics

In his book The Healing Power of Foods, nutritional expert Michael T. Murray details the natural medicinal properties of common foods. The following foods and spices are considered natural diuretics:

• watermelon
• horseradish
• pepper
• celery
• herbal salads that include ingredients such as dandelion leaves

Magnesium deficiency may occur with long-term use of the loop and thiazide diuretics. Symptoms include nausea and vomiting, muscle cramps, weakness (especially when exercising), insomnia, an irregular heartbeat, and difficulty sleeping. Calcium deficiency is a possible side effect of both loop and potassium-sparing diuretics. Signs of insufficient calcium in the body include a rapid heartbeat, muscle cramps, bone thinning, tooth decay, and difficulty sleeping.

Dehydration

Diuretic use in sports is usually prompted by the belief that a lower weight will improve athletic performance. However, the side effects experienced from long-term diuretic abuse typically offset any temporary gains in ability.

The main risk of diuretic abuse is severe dehydration. This is of special concern to athletes who might take the drug to "make weight" for sporting events or to improve performance. People exercising or participating in athletic competition are already at risk for dehydration because they are losing large amounts of fluids and electrolytes in their sweat. Diuretics can speed up this process.

Patients on doctor-prescribed diuretics must take extra precautions when exercising. These include: 1) drinking adequate amounts of water, sports drinks, or other non-caffeinated fluids; 2) wearing loose and comfortable clothing; 3) setting aside time for regular rest periods; and 4) watching for signs of heat exhaustion.

It is absolutely essential that a patient remain in regular touch with the prescribing doctor throughout the course of diuretic therapy.

Reactions with Other Drugs or Substances

Over-the-counter diuretic preparations are available in any drug store. Even though some diuretics are available without a prescription, the risk for serious side effects remains. Diuretics should always be taken under the recommendation and guidance of a trained healthcare professional.

Diuretics affect potassium levels. Drugs that are known to decrease potassium levels (certain anti-inflammatory steroids and heart drugs, for instance) should be avoided by anyone taking potassium-depleting diuretics. Potassium deficiencies can cause potentially dangerous side effects. In contrast, patients taking potassium-sparing diuretics such as amiloride, spironolactone, or triamterene should not eat foods high in potassium. The action of these diuretics raises the amount of potassium in their bodies. Thus, food rich in potassium—bananas, tomatoes, sweet potatoes, and oranges, to name a few—would only add to the problem and should be avoided.

Individuals taking prescription diuretics should always check with their doctors before adding herbal supplements

to their drug regimen. Herbal diuretics can actually increase the effect of prescription diuretics, so the two should not be combined. Some of the more well-known diuretic herbs include bilberry, celery seed, dandelion leaf, goldenrod, horse chestnut seeds, juniper, parsley, and St. John's wort. Foods and beverages rich in caffeine—such as chocolate, coffee, and tea—can also have a diuretic effect at high doses. They should not be consumed in excess with prescription diuretics. Alcohol has a diuretic effect as well and should be avoided by patients taking doctor-prescribed diuretics.

Treatment for Habitual Users

Treatment for diuretic abuse starts with examining an individual's reasons for taking the drugs. People mainly abuse diuretics in order to lose weight. These individuals include people with eating disorders as well as athletes trying to make a certain weight class.

Help for Disordered Eaters and Athletic Abusers

The National Eating Disorders Association Web site suggests that "the most effective and long-lasting treatment for an eating disorder is some form of psychotherapy or counseling, coupled with careful attention to medical and nutritional needs." Experts consider emotional support and behavioral therapy—sometimes referred to as "talk" therapy—essential for treatment and rehabilitation. It is vital to address the emotional motives and distorted thinking behind the behavior of a patient with an eating disorder.

The main goals of treatment are: 1) to stabilize the patient's weight; 2) to put an end to self-destructive behaviors, such as diuretic abuse, binge eating, and self-starvation; and 3) to help the patient relearn healthy nutritional practices. Patients with anorexia may be so severely malnourished that they require intravenous feeding in a hospital setting. Nutritional counseling and advice on lifestyle changes can help the patient reach and maintain a healthy weight.

What is an eating disorder? Some basic facts

Eating Disorders—such as anorexia, bulimia, and binge eating disorder—include extreme emotions, attitudes, and behaviors surrounding weight and food issues. Eating disorders are serious emotional and physical problems that can have life-threatening consequences for females and males.

Anorexia nervosa is characterized by self-starvation and excessive weight loss.

Symptoms include:

• Refusal to maintain body weight at or above a minimally normal weight for height, body type, age, and activity level
• Intense fear of weight gain or being "fat"
• Feeling "fat" or overweight despite dramatic weight loss
• Loss of menstrual periods
• Extreme concern with body weight and shape

Bulimia nervosa is characterized by a secretive cycle of binge eating followed by purging. Bulimia includes eating large amounts of food—more than most people would eat in one meal—in short periods of time, then getting rid of the food and calories through vomiting, laxative abuse, or over-exercising.

Symptoms include:

• Repeated episodes of bingeing and purging
• Feeling out of control during a binge and eating beyond the point of comfortable fullness
• Purging after a binge (typically by self-induced vomiting, abuse of laxatives, diet pills and/or diuretics, excessive exercise, or fasting)
• Frequent dieting
• Extreme concern with body weight and shape

Binge eating disorder (also known as compulsive overeating) is characterized primarily by periods of uncontrolled, impulsive, or continuous eating beyond the point of feeling comfortably full. While there is no purging, there may be sporadic fasts or repetitive diets and often feelings of shame or self-hatred after a binge. People who overeat compulsively may struggle with anxiety, depression, and loneliness, which can contribute to their unhealthy episodes of binge eating. Body weight may vary from normal to mild, moderate, or severe obesity.

Other eating disorders can include some combination of the signs and symptoms of anorexia, bulimia, and/or binge eating disorder. While these behaviors may not be clinically considered a full syndrome eating disorder, they can still be physically dangerous and emotionally draining. All eating disorders require professional help.

source: "What Is an Eating Disorder? Some Basic Facts," National Eating Disorders Association, Seattle, WA, 2003. www.NationalEatingDisorders.org

Athletes who abuse or misuse diuretics for purposes of performance enhancement or "making weight" face special treatment challenges. Coaches, trainers, and teammates may praise weight loss and an excessively low percentage of body fat, making it harder to change one's behavior. In addition, obsessive exercise and workout routines are often rewarded in sports and competition rather than questioned. In these cases, a treatment strategy must include educational training for the coaching and training staff as well as the athlete.

Consequences

Diuretics are not a psychoactive drug and have no direct mental effects on the user. However, abuse and misuse of this medication can lead to severe dehydration, which may bring on headaches, mental confusion, and even seizures.

Patients using diuretics for a specific medical reason under a doctor's supervision rarely experience problems. The misuse of diuretics, however, can result in serious consequences for the user. Diuretic use among people suffering from eating disorders can cause their health to worsen even further. Competitive athletes who misuse diuretics, either due to an eating disorder or for performance-enhancing purposes, usually find that their athletic performance suffers in the long run.

The Law

Diuretics are not controlled substances. Federal law does not regulate their possession and use. Some diuretic drugs are even available without a prescription. For those that do require a doctor's prescription, several rules apply to their use. The U.S. Food and Drug Administration (FDA) oversees the regulation of non-controlled drugs such as diuretics. Illegally selling or distributing prescription diuretics is against the law.

Professional athletes who test positive for diuretics in Olympic competition are suspended from participation in the games. They may also be stripped of any medals they have won. At the Summer Olympic Games in Athens, Greece, in 2004, Sanamachu Chanu of India was disqualified from competition after she tested positive for a banned diuretic. Her fourth-place finish in the weightlifting competition was tossed out.

Another incident occurred at the 2000 Olympics, when three Bulgarian weightlifters tested positive for the diuretic furosemide. The athletes involved were Izabela Dragneva, winner of the gold medal; Ivan Ivanov, winner of the silver medal; and Sevdalin Minchev, winner of the bronze medal. The International Olympic Committee took back the athletes' medals after they failed their mandatory drug tests. Alan Tsagaev, another Bulgarian weightlifter whose drug test was clean, went on to win the silver in his weight class. The coach of the Bulgarian team later took responsibility for the disqualification of his players. He claimed that he did not realize furosemide was one of the ingredients in a Bulgarian medicine named Orotsetam, which he had distributed to his team.

Diuretics appear on the World Anti-Doping Agency's "2005 Prohibited List" of drugs. Since 2000, the United States has stepped up its own investigation of performance-enhancing drugs in sports by forming the U.S. Anti-Doping Agency (USADA). The agency's main goal is "to provide clean athletes with a level playing field." According to the USADA's 2004 Testing and Results Management Numbers, the diuretic hydrochlorothiazide was one of nearly twenty "adverse findings" connected with doping violations for the year.

For More Information

Books

Murray, Michael T. The Healing Power of Foods: Nutrition Secrets for Vibrant Health and Long Life. Rocklin, CA: Prima Publishing, 1993.

Physicians' Desk Reference, 59th ed. Montvale, NJ: Thomson PDR, 2004.

Schull, Patricia Dwyer. Nursing Spectrum Drug Handbook. King of Prussia, PA: Nursing Spectrum, 2005.

Silverman, Harold M. The Pill Book, 11th ed. New York: Bantam, 2004.

Periodicals

Altman, Lawrence K. "Older Way to Treat Hypertension Found Best." New York Times (December 18, 2002): p. 1A.

Anderson, Kelli. "Losing to Win." Sports Illustrated for Women (May-June, 2001): p. 88.

"Diuretics Cut Heart Attack Risk." St. Louis Post-Dispatch (January 4, 2005): p. A5.

Krauskopf, Lewis. "Spreading the Word: Doctors Tout Value of Diuretics." The Record (March 2, 2005): p. L9.

Nagourney, Eric. "Healthier Hips, with Diuretics." New York Times (September 16, 2003): p. F6.

Nagourney, Eric. "More Bananas, Fewer Strokes?" New York Times (August 13, 2002): p. F6.

Stewart, Angela. "Water Pills Lower Risk of Stroke, Study Finds." Star-Ledger (January 4, 2005): p. 5.

Web Sites

"Coach Takes Responsibility for Failed Tests." ESPN.com, September 24, 2000. http://espn.go.com/oly/summer00/news/2000/0924/774153.html (accessed July 1, 2005).

"Eating Disorders: Facts about Eating Disorders and the Search for Solutions." National Institute of Mental Health.http://www.nimh.nih.gov/publicat/eatingdisorders.cfm (accessed July 1, 2005).

"Eating Disorders Information Index." National Eating Disorders Association.http://www.nationaleatingdisorders.org (accessed July 1, 2005).

Freudenrich, Craig C. "How Your Kidneys Work." How Stuff Works.http://science.howstuffworks.com/kidney.htm/printable (accessed July 1, 2005).

"How Your Kidneys Work." Kidney Learning System.http://www.kidney.org/kls/public/howkidneyswrk.cfm (accessed July 1, 2005).

"Lasker Awards: Former Awards." Lasker Foundation.http://www.laskerfoundation.org/awards/other.html (accessed July 1, 2005).

"News Release: The Changing Face of Eating Disorders." National Eating Disorders Association.http://www.nationaleatingdisorders.org/p.asp?WebPage_ID=805 (accessed July 1, 2005).

"Steroid Policy—Full." National Football League Players Association. http://www.nflpa.org/agents/main.asp?subpage=Steroid+Policy+−+Full&section=ALL (accessed July 5, 2005).

"United States Anti-Doping Agency's 2004 Annual Report." United States Anti-Doping Agency.http://www.usantidoping.org/files/active/resources/press_releases/2004%20USADA%20Annual%20Report.pdf (accessed July 1, 2005).

"What Are Electrolytes?" How Stuff Works.http://science.howstuffworks.com/question565.htm (accessed July 1, 2005).

"William Withering." BBC Historical Figures. http://www.bbc.co.uk/history/historic_figures/withering_william.shtml (accessed July 1, 2005).

"The World Anti-Doping Code: The 2005 Prohibited List." World Anti-Doping Agency.http://www.wada-ama.org/rtecontent/document/list_2005.pdf (accessed July 1, 2005).

See also: Caffeine; Creatine; Diet Pills; Herbal Drugs; Over-the-Counter Drugs

DIURETICS

OFFICIAL NAMES: Acetazolamide, amiloride, bendroflumethiazide, benzthiazide, bumetanide, chlorothiazide, chlorthalidone, dichlorphenamide, dorzolamide, ethacrynic acid, flumethiazide, furosemide, glycerin, isosorbide, hydrochlorothiazide (HCT), hydroflumethiazide, mannitol, methyclothiazide, metolazone, polythiazide, quinethazone, spironolactone, torsemide, triamterene, trichlormethiazide

STREET NAMES: Water pills

DRUG CLASSIFICATIONS: Not scheduled

OVERVIEW

Diuretics are a class of drugs that increase urine output. In healthcare, they are used to treat conditions that cause edema, or water retention. They are also prescribed for several chronic conditions, including asthma, heart disease, and hypertension (high blood pressure).

Because diuretics cause an overall water weight loss, they are often abused by individuals with eating disorders such as anorexia and bulimia. They may also be misused (and sometimes abused) by athletes to "make weight" for certain classes of competition (i.e., wrestling).

Diuretic use in sports may also be prompted by the belief that a lower weight will improve athletic performance. However, the side effects experienced from long-term diuretic abuse typically offset any temporary gains in ability. Diuretics are considered a banned substance by the International Olympic Committee (IOC), the United States Anti-Doping Agency (USADA), the World Anti-Doping Agency (WADA), the National Collegiate Athletic Association (NCAA), and a number of other national and international sporting authorities.

The term diuretics comes from the Greek diuresis, meaning "to urinate." In medieval medicine, diuretics were used to restore the body's humors (blood, bile, and phlegm) to balance, along with other "therapeutic" methods such as blood-letting and induced vomiting.

William Withering, an English physician with a strong interest in botany, was the first to introduce the diuretic digitalis (from the foxglove plant Digitalis purpurea) into common medical practice for the treatment of dropsy. Dropsy, a now-obsolete term for edema (fluid retention or swelling), was frequently related to congestive heart failure and was a common cause of death at the time for lack of an effective treatment.

Although there had been accounts of the use of foxglove in medicine since classical times, Withering was the first to standardize its use and establish digitalis as a legitimate medical therapy. He learned of the botanical therapy from local folk medicine, and began treating patients with it. Ten years after Withering began using the drug, he published An Account of the Foxglove and Some of Its Medical Uses; With Practical Remarks on Dropsy and Other Diseases (1785), in which he described his experiences with the drug and experiments with different preparations and dosages. Digitalis remains a treatment for heart failure today.

In the 1920s, researchers discovered the diuretic effects of substances known as organic mercurials that were used to treat a heart disorder related to syphilis. They were quickly employed as a treatment for congestive heart failure (CHF). While they helped edema, their long-term usefulness was limited since they became ineffective with regular use and, more importantly, they could be highly toxic to the heart and nervous system over time.

The antibiotic class of sulfonamides was introduced in 1936. Although not designed as a diuretic, the drug caused increased urinary output in patients who used it. Over a decade later, Dr. William Schwartz tried the drug on three heart patients and found it was effective for lowering blood pressure and relieving the symptoms of congestive heart failure, but also concluded that the drug could not be safely used for any length of time.

In 1957, researchers John Baer, Karl Beyer, James Sprague, and Frederick Novello formulated the drug chlorothiazide, the first of the thiazide diuretics. This groundbreaking discovery marked a new era in medicine as the first safe and effective long-term treatment for chronic hypertension and heart failure.

Loop diuretics, the next class of diuretic drugs to be developed, are also the most potent. Their introduction was a major advance in the treatment of congestive heart failure. Furosemide (Lasix), the first of the loop diuretics, debuted in 1965.

Over-the-counter diuretic formulations became available around this time as well. Pamabrom, a medication that relieves the fluid retention and bloating associated with a woman's menstrual cycle, is still the active ingredient in a number of over-the-counter preparations(e.g., Aqua-Ban, Pamprin).

There are also many drugs and dietary supplements that may have diuretic action as a side effect, but have a different primary purpose. For example, the supplement creatine is an ergogenic (energy-enhancer), but it also promotes fluid loss with regular use.

CHEMICAL/ORGANIC COMPOSITION

Diuretics work by increasing the amount of sodium and fluids excreted by the kidneys. Less fluid means less total blood volume and improved circulation and blood pressure. There are five main classes of the drug: loop diuretics, thiazide diuretics, potassium-sparing diuretics, osmotic diuretics, and carbonic anhydrase inhibitors.

Loop diuretics

The most potent type of diuretic, loop diuretics are named after the loop of Henle, a component of a nephron. The nephrons are the filtering units of the kidney, and are responsible for moving fluids and waste out of the bloodstream, resulting in urine formation. The loop of Henle is a branch within each nephron where sodium and potassium are reabsorbed back into the bloodstream instead of being filtered into the urine. Loop diuretics inhibit this action and promote excretion of the sodium and potassium instead, along with calcium and magnesium. Since excess sodium causes excess fluid build-up, this results in fluid loss. Furosemide (Lasix), bumetanide (Bumex), torsemide (Demadex), and ethacryinic acid (Edecrin) are all loop diuretics.

Thiazide diuretics

Thiazide diuretics such as chlorothiazide (Diuril) and hydrochlorothiazide (HCTZ) work by blocking the action of aldosterone, a hormone that promotes sodium reabsorption by the kidneys. They are potassium-depleting

diuretics, meaning that they cause a loss of potassium, known as hypokalemia.

Potassium-sparing diuretics

Potassium-sparing diuretics include amiloride (Midamor) and triamterene (Dyrenium). They are used in the treatment of cirrhosis and congestive heart failure. They may be used in conjunction with thiazide diuretics to offset the potassium loss associated with those medications.

Osmotic diuretics

As their name suggests, osmotic diuretics such as mannitol (Osmitrol), isosorbide (Ismotic), and glycerin (Osmoglyn) draw fluid from the tissues of the body through principles of osmosis. Osmotic diuretics are typically given to treat or prevent acute renal failure (kidney failure). They may also be used to relieve intracranial pressure (swelling of the brain) in cases of head injury or hydrocephalus.

Carbonic anhydrase inhibitors

Carbonic anhydrase inhibitors such as dorzolamide (Trusopt) and dichlorphenamide (Daranide) are used to treat glaucoma patients and altitude sickness. Acetazolamide (Diamox), a carbonic anhydrase inhibitor, is also used to treat seizures related to epilepsy. CA inhibitors work by promoting the excretion of sodium and bicarbonate.

INGESTION METHODS

Diuretics are most commonly available in pill form. In a hospital setting, they may be administered intravenously or injected. Carbonic anhydrase inhibitors may be administered in eye drop form [dorzolamide (Trusopt)] to glaucoma patients.

THERAPEUTIC USE

Diuretics are prescribed in cases where excess fluids in bodily tissues (edema) cause illness, discomfort, or medical complications.

Medical conditions that may warrant the use of diuretics include:

Hypertension (high blood pressure)

A standard treatment for hypertension, diuretics flush excess water and sodium from the body. They also lower blood pressure by reducing the total volume of fluid in the bloodstream. A reduced total volume of blood means that the heart does not have to work as hard to circulate it through the body.

Often, diuretics are used in combination with other drugs to relieve hypertension. Types of diuretics used to treat hypertension include thiazides, such as chlorothiazide (Diuril) and hydrochlorothiazide (Esidrex); potassium-sparing diuretics, such as spironolactone (Aldactone); and loop diuretics, such as furosemide (Lasix).

Congestive heart failure (CHF)

Congestive heart failure occurs when the pumping ability of the heart is impaired, and the heart itself becomes enlarged. This may be due to coronary artery disease, chronic hypertension, diabetes, arrhythmia (irregular heartbeat), infection, or a heart valve disorder. The result is edema, or swelling caused by fluid retention, a major symptom of congestive heart failure. Patients with CHF experience swollen legs, ankles, feet, and/or fluid in the lungs (pulmonary edema). Sometimes fluid builds up around other organs, such as the liver, as well. Loop diuretics such as furosemide (Lasix) are frequently prescribed to alleviate edema from congestive heart failure. Thiazide and potassium-sparing diuretics may also be prescribed.

Other drugs that may be prescribed in conjunction with diuretics for the treatment of CHF include vasodilators (drugs that dilate blood vessels, such as ACE inhibitors); inotropics (drugs that increase the heart's ability to contract, such as digoxin); and beta blockers (drugs that inhibit the action of epinephrine, such as carvedilol).

Diabetes insipidus

Also known as water diabetes, diabetes insipidus (DI) is a rare chronic disease that causes excessive urination. If not properly treated, it can result in electrolyte imbalance and dehydration. It may be caused by a number of factors, including lithium use (a psychiatric drug used for bipolar disorder), neurological disease, or an inadequate amount of ADH (anti-diuretic hormone, or vasopressin, which is produced by the pituitary gland). DI caused by insufficient ADH is called central diabetes insipidus.

Nephrogenic diabetes insipidus, which occurs less often than central diabetes insipidus, is characterized by the inability of the kidneys to reabsorb water into the bloodstream. Treatment with thiazide or potassium-sparing diuretics can help maintain a fluid and electrolyte balance in some individuals with diabetes insipidus.

Other

Diuretics may also be prescribed for a number of other disorders and conditions that trigger fluid retention, including:

• Nephrotic syndrome. Thiazide or loop diuretics are used in the treatment of this kidney disorder that causes increased protein in the urine.
• Cirrhosis. Potassium-sparing diuretics are frequently prescribed for the patients with this liver disease.
• Renal hypercalciuria (kidney stones). Thiazide diuretics such as metolazone (Zaroxolyn) that increase calcium levels in the body are used in the treatment of kidney stones.
• Water retention related to menstruation. Pamabrom, an ingredient in over-the-counter diuretic preparations, can relieve bloating related to a woman's menstrual cycle.

Several studies have shown that thiazide diuretics prevent calcium loss in bones, which may improve bone density and protect against osteoporosis. Preliminary research also suggests that diuretics are helpful in preventing stroke. Further studies are needed to confirm these findings.

USAGE TRENDS

The U.S. Centers for Disease Control (CDC) and the National Center for Health Statistics (NCHS) report that cardiovascular-renal drugs (including diuretics, beta blockers, and calcium channel blockers) were the most frequently prescribed medications in the United States in 1999 (the most recent year for which data was available). In fact, the loop diuretic Lasix was the second most frequently prescribed medication overall, with more than12.9 million prescriptions written. It was second only to the allergy drug Claritin.

Scope and severity

Statistics on the misuse of diuretic drugs are more difficult to determine. Estimates vary as to the number of people currently suffering from eating disorders, and not all individuals with an eating disorder abuse diuretics. In addition, the sense of shame and emotional turmoil associated with the disease make the unreported incidence of eating disorders high. Federal and institutional estimates put the number at approximately 5–8 million Americans.

Age, ethnic, and gender trends

According to the National Institutes of Mental Health (NIMH), up to 3.7% of females suffer from anorexia, and up to 4.2% of females suffer from bulimia at some point in their lives. Males develop eating disorders much less frequently, representing only 5–15% of all U.S. cases of anorexia or bulimia.

The 1999 text Mental Health: A Report of the Surgeon General, states that the mortality, or death rate, among females age 15–24 with anorexia is an estimated 0.56% per year, approximately 12 times higher than that of girls of the same age in the general population. In addition to medical problems related to eating disorders, anorexia and bulimia are frequently accompanied by other psychiatric disturbances, including mood disorders (depression, anxiety) and substance abuse. Depression is the third leading cause of death for adolescents ages 15–24, and the eleventh leading cause of death for Americans of all ages.

In a Wesleyan University study of binge eating disorder (BED) published in 2000, researchers found that African-American women with the disorder reported laxative and diuretic abuse more frequently than white women. However, BED was considered a significant health problem in both racial groups.

Diuretic use and eating disorders in sports and professional athletics are growing concerns both in the United States and abroad. Sports that require weigh-ins, from wrestling to regatta sailing, can put the pressure on athletes to take extreme measures to lose weight quickly. Often, those measures include diuretic abuse, rubber suits, starvation diets, exposure to high temperatures, and other unsafe practices that can put athletes at risk for severe dehydration and even death.

A 1996 report in the journal Pediatrics that looked at a variety of studies and surveys of athletic weight-control practices reported that up to 52% of female collegiate athletes had engaged in unhealthy weight-control behaviors including diuretic use.

Weight loss in athletes is sometimes encouraged by coaching staff, as well. In sports such as gymnastics, swimming, and track—where "smaller is better"—female athletes in particular often develop eating disorders and unhealthy weight loss practices, including diuretic abuse. A 1999 NCAA-sponsored study of college athletes found that 13% of female athletes surveyed showed signs of bulimia or anorexia, and an additional 36% were considered at risk for developing an eating disorder. In addition, 3.89% of female and 3.65% of male athletes surveyed reported diuretic use for the purpose of purging at least once in their lifetime. In addition, one-fourth of the males surveyed used saunas or steam baths to lose weight at least once a week and 4.4% of females vomited for weight loss. Female athletes who develop eating disorders or eating disordered behavior are at a higher risk for osteoporosis and amenorrhea (interruption of the menstrual cycle).

MENTAL EFFECTS

Diuretics are not a psychoactive drug and have no direct mental effects. However, abuse and misuse of this medication can lead to severe dehydration, which may lead to headaches and mental confusion.

Because they affect sodium, potassium, and chloride levels in the body, diuretics can trigger electrolyte imbalances. An electrolyte imbalance can cause a variety of neurological symptoms, including confusion, fainting, dizziness, and headache.

PHYSIOLOGICAL EFFECTS

Diuretics increase urine and sodium output, and in some cases they may also increase urinary output of potassium, calcium, and magnesium. In large quantities, they can affect electrolyte balance.

Harmful side effects

The main risk of diuretic abuse is severe dehydration. This is of special concern to athletes who might take the drug to make weight for sporting events or to improve performance. Anyone exercising or participating in athletic competition is already at risk for dehydration from the fluids they are losing from sweating; diuretics can accelerate the process.

Anyone who must take diuretics for therapeutic purposes should take the proper precautions when exercising. This includes adequate and regular intake of water, sports drinks, or other non-caffeinated fluids; loose and comfortable clothing; adequate rest periods; and awareness of the signs of heat exhaustion (clammy and cool skin, fatigue, nausea, weakness, confusion, vision disturbances, and a possible loss of consciousness).

Other common side effects of diuretic use may include:

• rash
• nausea
• dizziness
• urinary incontinence
• photosensitivity (a sensitivity to sunlight)
• high blood glucose levels (blood sugars)

Other side effects that have been reported with diuretic use, but are not considered common, include:

• hearing loss
• pancreatitis
• anemia
• leukopenia (depletion of white blood cells)

Potassium-sparing diuretics (e.g., spironolactone, amiloride, triamterene) may cause a dangerous build-up of excessive potassium in the body. Signs of hyperkalemia, or excess potassium, include:

• arrhythmia (irregular heartbeat)
• breathing difficulties
• numbness or tingling sensation in the hands or feet
• fatigue
• weakness
• anxiety and/or difficulty concentrating

The potassium-depleting diuretics (e.g., hydro-chlorothiazide, chlorthalidone, metolazone) cause potassium loss that may be reversed by supplementation and/or dietary adjustments. As previously stated, potassium can be harmful in high amounts, so any supplementation should be recommended and supervised by a doctor.

• fast or irregular heartbeat
• muscle cramps
• nausea and/or vomiting
• dry mouth and persistent thirst
• fatigue
• weakness
• mood swings

Although diuretics may sometimes be given to pregnant women suffering from preeclampsia, in general, diuretic use is usually not recommended in pregnancy because of the potential risk to the developing fetus. In addition, some diuretics may pass through into breast milk and can cause lactation problems. Therefore, women who are pregnant or breastfeeding should always check with their doctor before taking diuretics.

Certain types of diuretics may be contraindicated (not recommended) for use by people with chronic medical conditions, including diabetes, pancreatitis, and lupus erythematosus. Anyone with a known allergy to diuretics or to sulfa drugs should alert their doctor before taking a diuretic.

Long-term health effects

Anyone taking diuretics for longer than six months may experience a folate, or folic acid, deficiency. Folic acid plays a part in the health and reproduction of virtually every cell in the body. It is responsible for protein metabolism, the prevention of neural tube defects in pregnancy, blood cell production, and the synthesis of neurotransmitters. Individuals with folate deficiencies may suffer from anemia, depression and other mood disorders, and may give birth to babies with neural tube defects. Supplementation with folic acid may be useful in reversing these effects.

Individuals on long-term diuretic therapy may also experience elevated levels of homocysteine, an amino acid regulated by folate. High homocysteine levels increase the risk of heart disease. Thiamin, or vitamin B₁, depletion is another possible side effect of loop diuretics. Individuals with thiamin deficiencies are at risk for fatigue, heart enlargement, muscle cramps, heart rate irregularities, and impaired mental function.

Insufficient zinc intake is another possible side effect of diuretic use. Individuals with zinc deficiency may experience hair loss, problems with night vision, slow wound healing, dermatitis, and a predisposition to infection and illness due to lowered immune function.

Because diuretics affect electrolyte balance, they can cause deficiencies in magnesium and calcium as well as the previously mentioned potassium. Magnesium deficiency may occur with chronic use of the loop and thiazide diuretics. Symptoms include nausea and vomiting, muscle cramps and weakness, insomnia, arrhythmia (irregular heartbeat), difficulty sleeping, and a loss of exercise tolerance. Calcium deficiency is a possible side effect of both loop and potassium-sparing diuretics. Signs of insufficient calcium in the body include muscle cramps, low bone density (which may be indicated by bones that break easily), tooth decay, heart palpitations, and difficulty sleeping.

REACTIONS WITH OTHER DRUGS OR SUBSTANCES

Although over-the-counter diuretic preparations are available without a prescription, because of the risk for serious and potentially fatal complications and side effects, diuretics should always be taken under the recommendation and guidance of a trained healthcare professional.

Certain medications may impair or enhance the therapeutic effects of diuretic drugs. Anyone prescribed a diuretic should inform their physician of all other drugs and supplements they are taking in case of a possible interaction.

Drugs that are also known to decrease potassium levels, such as glucocorticoids and digoxin, should be avoided by anyone taking potassium-depleting diuretics. If they are prescribed, a physician should closely monitor the potassium levels of the patient. Potassium deficiency, or hypokalemia, can cause serious and potentially dangerous side effects (see Harmful side effects section).

Potassium-sparing diuretics, such as amiloride (Midamor), spironolactone (Aldactone), and triamterene (Dyrenium), impair the ability of the kidneys to filter potassium from the body. This can result in a condition called hyperkalemia, or excessive potassium, a potentially dangerous situation (see Harmful side effects section). Anyone taking potassium-sparing diuretics should avoid excessive dietary intake of foods high in the mineral. Bananas, tomatoes, sweet potatoes, and oranges are some of the foods that are rich in potassium.

Diuretics may also interact with herbs and dietary supplements. Licorice (Glycyrrhiza glabra) can lower potassium levels, and should be avoided with potassium-sparing diuretics. In addition, herbal diuretics can amplify, or increase, the effect of prescription diuretics. Some of the more well-known diuretic herbs include bilberry (Vaccinium myrtillus), celery seed (Apium graveolens), dandelion leaf (Taraxacum officinale), and elder flower (Sambucus nigra, S. canadensis), goldenrod (Solidago virgaurea), horse chestnut seeds (Aesculus hippocastanum), horsetail (Equisetum arvense), juniper (Juniperus communis), parsley (Petroselinum sativum), St. John's wort (Hypericum perforatum), and uva ursi (bearberry; Arctostaphylos uva ursi). Just because a preparation is labeled natural does not mean it cannot cause harmful interactions with other medications and substances. Individuals should always check with their physician or healthcare professional before taking herbal and supplement products with diuretics.

Foods and beverages rich in caffeine, such as coffee, tea, and chocolate, can also have a diuretic effect at high doses, and should not be taken in excess with prescription diuretics. Alcohol has a diuretic effect as well, and should be avoided in individuals taking a diuretic medication.

TREATMENT AND REHABILITATION

Treatment for diuretic abuse starts with addressing the roots of the physical or psychological problems. There are a number of rehabilitation programs available for the treatment of eating disorders such as bulimia, anorexia, and binge eating disorder (BED). Programs are usually residential, or inpatient, meaning that the patient lives in the hospital or other rehabilitation facility for the length of treatment (several weeks to several months).

The first goal of rehabilitation from any eating disorder is to stabilize both weight and self-destructive behavior such as diuretic abuse and binge eating. Patients with anorexia may be severely malnourished, and could have additional related health problems such as impaired kidney function and dehydration that need immediate medical attention. They may also require intravenous feeding.

Patients need to relearn healthy nutrition, meal management, and exercise patterns. Taking regularly scheduled meals, meeting with a registered dietitian, and participating in classes on appropriate nutrition and fitness will help to establish good habits. Overweight individuals being treated for binge eating disorder may also learn new healthy and realistic strategies for weight loss in this environment.

Equally important is the effective treatment of eating disorders and associated diuretic abuse is to address the emotional motives and distorted thinking behind the patient's behavior. Individual or group psychotherapy or cognitive-behavioral therapy can help the patient work through self-esteem and self-image problems. Studies show that cognitive behavioral therapy has a 40-50% success rate with bulimia nervosa and BED patients. Family therapy may also be part of the treatment program.

The goal of cognitive-behavioral therapy (CBT) is to teach the patient new behaviors by exposing the irrational thoughts that trigger the old, self-destructive behaviors of anorexia or bulimia. Once the disordered thinking is changed, the behavior will follow. Learning how to recognize the thoughts and emotions surrounding eating disordered behavior, and rehearsing the new and desirable behaviors (such as avoiding situations and places that trigger the old behavior), is a key part of long-term recovery and relapse prevention with CBT.

If the patient has a pre-existing mood disorder, such as depression or anxiety disorder, antidepressant medication may also be prescribed. Studies have shown that the selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine (Prozac) and sertraline (Zoloft) are effective in people with bulimia and anorexia. These medications reduce depression by increasing levels of serotonin, a neurotransmitter.

Eating disorders can be chronic conditions that need life-long vigilance and attention. A 1999 Harvard Medical School study of 246 women with eating disorders found that one-third of patients relapsed, or returned to eating disordered behaviors, following initial full recovery from both bulimia and anorexia.

Athletes who abuse or misuse diuretics for purposes of performance enhancement or making weight face special treatment challenges. Weight loss and an excessively low percentage of body fat may be praised by coaches, trainers, and teammates, making behavioral changes even more difficult. In addition, obsessive exercise and workout routines may be rewarded in sports and competition rather than questioned. A treatment strategy that includes education of not just the athlete, but also the people around him or her, is essential.

PERSONAL AND SOCIAL CONSEQUENCES

Urinary incontinence, or leakage, that may be associated with diuretic use can cause social embarrassment, self-esteem issues, depression, and anxiety. A person suffering from incontinence may stop participating in social activities, sports, and other activities they once enjoyed because of the risk of embarrassing "accidents." Bladder training, biofeedback, pelvic toning exercises, or special urethral or vaginal inserts may help to treat urinary incontinence problems related to diuretics.

While uncomplicated diuretic use itself has little impact on personal and social well-being, the conditions associated with misuse of the medication can have serious consequences. Aside from the physical problems associated with eating disorders, the dysfunctional behavior itself can greatly affect relationships with friends and family and basic social functioning. Individuals with eating disorders may avoid going out with friends to eat or drink socially. Their rigid schedules of bingeing and purging and/or exercise may take over their life to the extent that they withdraw socially.

Competitive athletes who misuse diuretics, either due to an eating disorder or for performance-enhancing purposes, may be suspended or banned from competition. In addition, if diuretic use becomes chronic and spirals into other eating disordered behaviors, athletic performance will ultimately suffer, and the athlete may face added pressures from coaching staff and teammates.

LEGAL CONSEQUENCES

Diuretics are not a controlled substance, and over-the-counter brands are easily and legally accessible in the United States and throughout the world.

Professional athletes who test positive for diuretics in the Olympics are suspended from participation in the games. They may also be stripped of any medals they have won in competition. Testing for banned substances may be conducted in competition or out of competition.

Federal guidelines, regulations, and penalties

The U.S. Food and Drug Administration (FDA) is the federal authority that oversees the regulation of non-controlled drugs such as diuretics. Any legal penalties for trafficking (illegally selling or distributing) prescription diuretics would typically be determined at the state level unless the charges involved theft from a federal facility such as a VA (Veterans Administration) hospital.

See also Caffeine

RESOURCES

Books

Medical Economics Corporation. Physicians' Desk Reference (PDR). 56^th Edition. Montvale, NJ: Medical Economics, 2002.

Otis, Carol and Roger Goldingay. The Athletic Woman's Survival Guide: How to Win the Battle Against Eating Disorders, Amenorrhea, and Osteoporosis. Champaign, IL: Human Kinetics, 2000.

Periodicals

Anderson, Kelli. "Losing to Win." Sports Illustrated for Women 3, no. 3 (May/June 2001): 88+.

Hoel, Donna, and Robert Howard. "Hypertension: Stalking the Silent Killer." Postgraduate Medicine 101, no. 2 (February1997). Available at: <http://www.postgradmed.com/issues/1997/02_97/hoel.htm>. Accessed April 1, 2002.

Other

National Institute of Mental Health. <http://www.nimh.nih.gov/publicat/eatingdisordersmenu.cfm>. Facts About Eating Disorders. Accessed April 1, 2002.

U.S. Anti-Doping Agency (USADA). <http://www.usantidoping.org/>. Accessed April 1, 2002. Drug reference line: 1-800-233-0393.

Organizations

National Eating Disorders Association, 603 Stewart St., Suite 803, Seattle, WA, USA, 98101, (206) 382-3587, info@NationalEatingDisorders.org, <http://www.nationaleatingdisorders.org/>.

Paula Anne Ford-Martin

Diuretics

Definition

Diuretics are drugs that help to reduce the amount of water in the body. They are sometimes called water pills.

Purpose

Diuretics are used to treat the buildup of excess fluid in the body. Medical conditions such as congestive heart failure , liver disease, kidney disease, and hormonal imbalances can cause fluid to accumulate and tissues to swell (edema ). Certain medications can also cause water retention. When there is too much fluid in the body, blood pressure increases and the heart must work harder to pump. Therefore, diuretics are also often the first drug prescribed to treat high blood pressure (hypertension ). They are the least expensive drug that effectively treats hypertension in many people.

When blood enters the kidney, water, waste products, and dissolved charged particles (ions) such as sodium (Na) and potassium (K) are filtered out of the blood and into special tubules in the kidneys. As they travel through these tubules, some water and particles are reabsorbed, and the rest are excreted as urine. In general, diuretics work by increasing the amount of ions and water that are excreted, thus increasing urine output and reducing the fluid load of the body. This, in turn, lowers blood pressure and reduces tissue swelling so that the heart does not have to work as hard.

Diuretics also may be used in surgery to reduce blood pressure and swelling. For example, mannitol, an osmotic diuretic, may be used to reduce swelling in the brain in some neurosurgical procedures.

Description

There are several classes of diuretics. Each class works in a slightly different way, although the end function of all diuretics is to eliminate excess water from the body. The different classes of diuretics include:

• Loop diuretics include bumetanide (Bumex), furosemide (Lasix), torsemide (Cemadex), and ethacrynic acid (Edecrin). They get their name from the loop-shaped part of the kidney tubules (the loop of Henle) where they have their effect.
• Thiazide and thiazide-like diuretics include such commonly used diuretics as hydrochlorothiazide (HydroDIURIL, Esidrix), chlorothiazide (Diuril), and chlorthalidone (Hygroton).
• Potassium-sparing diuretics help the body retain potassium while losing sodium and water. With many diuretics, potassium is lost from the body along with sodium. Too little potassium can cause serious health problems, because potassium plays a critical role in many metabolic functions. Examples of potassium-sparing diuretics are spironolactone (Aldactone), amiloride (Midamor) and triamterene (Dyrenium).
• Osmotic diuretics keep water from being reabsorbed in the kidney. Mannitol, which is given by intravenous drip, is commonly used to reduce cerebral edema (swelling of the brain). Glycerol is also an osmotic diuretic. Osmotic diuretics are used under special circumstances and are not routinely given to control high blood pressure.
• Carbonic anhydrase inhibitors cause water loss through the kidneys by changing the acidity of urine, but their most common use is in treatment of glaucoma, an eye disease caused by increased pressure in the eye. Acetazolamide (Diamox), dichlorphenamide (Daranide), and methazolamide (Nepatazane) are often given by mouth, even though they primarily treat an eye condition.

In addition, some drugs contain combinations of two diuretics. The brands Dyazide and Maxzide, for example, contain the thiazide diuretic hydrochloro-thiazide along with the potassium-sparing diuretic triamterene.

KEY TERMS

Lupus erythematosus —A chronic autoimmune disease that affects the skin, joints, and certain internal organs.

Pancreas —A gland located near the liver, the pancreas produces enzymes and fluids that help to breakdown food. It also produces the hormone insulin that the body must have to utilize sugar (glucose).

Potassium —A mineral found in whole grains, meat, legumes, and some fruits and vegetables. Potassium is important for many body processes, including proper functioning of nerves and muscles.

Triglyceride —A substance formed in the body from the breakdown of fat in the diet. Triglycerides are the main fatty materials in the blood. Triglyceride levels are important in the diagnosis and treatment of many diseases, including high blood pressure, diabetes, and heart disease.

Some nonprescription (over-the-counter, OTC) medicines and herbal remedies also function as diuretics. However, the drugs described here cannot be bought without a physician's prescription. They are available in tablet, capsule, liquid, and injectable forms.

Recommended dosage

The recommended dosage depends on the type of diuretic, the condition it treats, and the individual's size, age, and health. Patients should check with the physician who prescribed the drug or the pharmacist who filled the prescription for the correct dosage and then take the medicine exactly as directed.

Precautions

Seeing a physician regularly while taking a diuretic is important. The physician may order blood work and will do a physical examination to make sure the diuretic is working as it should without unwanted side effects.

For patients taking a class of diuretic that can cause large amounts of potassium to be excreted, physicians may recommend adding potassium-rich foods such as bananas to the diet , and they may suggest taking a daily potassium supplement. If the

physician recommends any of these measures, the patient must make sure to closely follow the directions. The patient should not make other significant diet changes or take any dietary supplements without checking with the physician. People who are taking potassium-sparing diuretics should not add potassium to their diets, as too much potassium may be harmful.

Patients taking potassium-sparing diuretics should know the signs of too much potassium and should check with a physician as soon as possible if any of these symptoms occur, including:

• irregular heartbeat
• breathing problems
• numbness or tingling in the hands, feet, or lips
• confusion or nervousness
• unusual tiredness or weakness
• weak or heavy feeling in the legs

Patients taking diuretics that cause potassium loss should know the signs of too little potassium and should check with a physician as soon as possible if they have any of these symptoms, including:

• fast or irregular heartbeat
• weak pulse
• nausea or vomiting
• dry mouth
• excessive thirst
• muscle cramps or pain
• unusual tiredness or weakness
• mental or mood changes

People who become ill with gastrointestinal diseases while taking diuretics may lose too much water or potassium if they have severe vomiting and diarrhea .

Diuretics drugs make some people feel light-headed, dizzy, or faint when they get up after sitting or lying down. Older people are especially likely to have this problem. Drinking alcohol, exercising, standing for long periods, or being outdoors in hot weather may make the problem worse. To lessen this problem, a person should get up gradually and hold onto something for support if possible. The patient should avoid or limit the amount of alcohol he or she drinks and be careful in hot weather or when exercising or standing for a long time.

People who take a diuretic should tell the health-care professional before having surgical or dental procedures, medical tests, or emergency treatment.

Special conditions

People who have certain medical conditions or who are taking certain other drugs may encounter problems if they take diuretics. Before taking diuretic drugs, they should be sure to let the physician know about these conditions.

ALLERGIES Anyone who has had unusual reactions to diuretics or sulfonamides (sulfa drugs) in the past should let the physician know. The physician should also be told about any allergies to foods, dyes, preservatives, or other substances.

PREGNANCY Diuretics will not help the swelling of hands and feet that some women experience during pregnancy. Pregnant women should not use diuretics unless prescribed by their obstetrician or other physician. Although studies have not been done on pregnant women, studies of laboratory animals show that some diuretics can cause harmful effects when taken during pregnancy.

BREASTFEEDING Some diuretics pass into breast milk, but no reports exist of problems in nursing babies whose mothers use this medicine. However, thiazide diuretics may decrease the flow of breast milk. Women who are breastfeeding and need to use a diuretic should check with the physician.

OTHER MEDICAL CONDITIONS Side effects of some diuretics may be more likely in people who have had a recent heart attack or who have liver disease or severe kidney (renal) disease. Other types of diuretics may not work properly in people with liver disease or kidney disease. Diuretics may worsen certain medical conditions such as gout , kidney stones , pancreatitis, lupus erythematosus, and hearing problems. In addition, people with diabetes should be aware that a diuretic may increase blood sugar levels. People with heart or blood vessel disease should know that some diuretics increase cholesterol or triglyceride levels.

The risk of an allergic reaction to certain diuretics is greater in people with bronchial asthma . Before using diuretics, people with any of these medical conditions should make their physicians aware of their medical history. Also, people who have trouble urinating or who have high blood levels of potassium may not be able to take diuretics and should discuss these conditions with their physician before using them.

Side effects

Some people feel unusually tired when they first start taking diuretics. This effect usually becomes less noticeable over time, as the body adjusts to the medicine. Other side effects, such as loss of appetite, nausea, vomiting, stomach cramps, diarrhea, and dizziness , usually lessen or go away as the body adjusts to the diuretic drug. These problems usually do not need medical attention unless they continue or interfere with normal activities.

Some diuretics make the skin more sensitive to sunlight. Even brief exposure to sun can cause severe sunburn, itching , a rash, redness, or other changes in skin color. While being treated with this medicine, the person should avoid being in direct sunlight; wear a hat and tightly woven clothing that covers the arms and legs; use a sunscreen with a skin protection factor (SPF) of at least 15; protect the lips with a sun-block lipstick; and not use tanning beds, tanning booths, or sunlamps. People with fair skin may need to use a sunscreen with a higher SPF.

Because diuretics increase urine output, people who take this medicine may need to urinate more often, even during the night. Healthcare professionals can help patients schedule their doses to avoid interfering with their sleep or regular activities.

Interactions

Diuretics may interact with other drugs, herbs, or dietary supplements. When this occurs, the effects of one or both of the drugs become either more or less effective or the risk of side effects may increase. Anyone who takes a diuretic should inform the healthcare providers about all other prescription and over-the-counter drugs, herbs, and dietary supplements that he or she is taking in order to avoid harmful interactions.

Some common drugs that may interact with diuretics include:

• Angiotensin-converting enzyme (ACE) inhibitors such as benazepril (Lotensin), captopril (Capoten), and enalapril (Vasotec), which are used to treat high blood pressure. Taking these drugs with potassium-sparing diuretics may cause levels of potassium in the blood to be too high, increasing the chance of side effects.
• Cholesterol-lowering drugs such as cholestyramine (Questran) and colestipol (Colestid). Taking these drugs with combination diuretics such as Dyazide and Maxzide may keep the diuretic from working. The person should take the diuretic at least one hour before or four hours after the cholesterol-lowering drug.
• Cyclosporine (Sandimmune), a drug that suppresses the immune system. Taking this medicine with potassium-sparing diuretics may increase the chance of side effects by causing levels of potassium in the blood to be too high.
• Potassium supplements, other drugs or supplements containing potassium, or salt substitutes that contain potassium. Taking these with potassium-sparing diuretics may lead to too much potassium in the blood, increasing the chance of side effects.
• Lithium, used to treat bipolar disorder (manicdepressive illness). Using this medicine with potassium-sparing diuretics may allow lithium to build up to poisonous levels in the body.
• Digitalis, also called digoxin (Lanoxin) or digitoxin. Using this medicine with combination diuretics such as triamterene-hydrocholorthiazide (Dyazide, Maxzide) increases the chance of irregular heartbeat.

The list above does not include every drug or herb that may interact with diuretics. The patient should check with a physician or pharmacist before combining diuretics with any other prescription or over-the-counter drugs, herbal medicines, or dietary supplements.

Resources

books

Rubin, Alan L. High Blood Pressure for Dummies 2nd ed. Indianapolis, IN: Wiley Pub., 2007.

organizations

American Heart Association. 7272 Greenville Avenue, Dallas, TX 75231. (800) 242-8721. http://www.americanheart.org (accessed March 19, 2008).

other

Anaizi, Nasr. “Diuretics.” The Drug Monitor [cited March 19, 2008]. http://www.thedrugmonitor.com/diuretics.html

“Diuretics.” Mayo Clinic. December 22, 2006 [cited March 19, 2008]. http://www.mayoclinic.com/health/diuretics/HI00030

“Diuretics Key Factor in Preventing Heart Failure."American Heart Association. May 1, 2006 [cited March 19, 2008]. http://www.americanheart.org/presenter.jhtml?identifier=3039311

Nancy Ross-Flanigan

Sam Uretsky PharmD

Tish Davidson A.M.

Diuretics

Definition
Purpose
Description
Recommended dosage
Precautions
Side effects
Interactions

Definition

Diuretics are drugs that help to reduce the amount of water in the body. They are sometimes called water pills.

Purpose

Diuretics are used to treat the buildup of excess fluid in the body. Medical conditions such as congestive heart failure, liver disease, kidney disease, and hormonal imbalances can cause fluid to accumulate and tissues to swell (edema). Certain medications can also cause water retention. When there is too much fluid in the body, blood pressure increases and the heart must work harder to pump. Therefore, diuretics are also often the first drug prescribed to treat high blood pressure (hypertension). They are the least expensive drug that effectively treats hypertension in many people.

When blood enters the kidney, water, waste products, and dissolved charged particles (ions) such as sodium (Na) and potassium (K) are filtered out of the blood and into special tubules in the kidneys. As they travel through these tubules, some water and particles are reabsorbed, and the rest are excreted as urine. In general, diuretics work by increasing the amount of ions and water that are excreted, thus increasing urine output and reducing the fluid load of the body. This, in turn, lowers blood pressure and reduces tissue swelling so that the heart does not have to work as hard.

Diuretics also may be used in surgery to reduce blood pressure and swelling. For example, mannitol, an osmotic diuretic, may be used to reduce swelling in the brain in some neurosurgical procedures.

Description

There are several classes of diuretics. Each class works in a slightly different way, although the end function of all diuretics is to eliminate excess water from the body. The different classes of diuretics include:

Loop diuretics include bumetanide (Bumex), furosemide (Lasix), torsemide (Cemadex), and ethacrynic acid (Edecrin). They get their name from the loop-shaped part of the kidney tubules (the loop of Henle) where they have their effect.

• Thiazide and thiazide-like diuretics include such commonly used diuretics as hydrochlorothiazide (HydroDIURIL, Esidrix), chlorothiazide (Diuril), and chlorthalidone (Hygroton).
• Potassium-sparing diuretics help the body retain potassium while losing sodium and water. With many diuretics, potassium is lost from the body along with sodium. Too little potassium can cause serious health problems, because potassium plays a critical role in many metabolic functions. Examples of potassium-sparing diuretics are spironolactone (Aldactone), (amiloride (Midamor) and triamterene (Dyrenium).
• Osmotic diuretics keep water from being reabsorbed in the kidney. Mannitol, which is given by intravenous drip, is commonly used to reduce cerebral edema (swelling of the brain). Glycerol is also an osmotic diuretic. Osmotic diuretics are used under special circumstances and are not routinely given to control high blood pressure.
• Carbonic anhydrase inhibitors cause water loss through the kidneys by changing the acidity of urine, but their most common use is in treatment of glaucoma, an eye disease caused by increased pressure in the eye. Acetazolamide (Diamox), dichlorphenamide (Daranide), and methazolamide (Nepatazane) are often given by mouth, even though they primarily treat an eye condition.

In addition, some drugs contain combinations of two diuretics. The brands Dyazide and Maxzide, for example, contain the thiazide diuretic hydrochlorothiazide along with the potassium-sparing diuretic triamterene.

KEY TERMS

Lupus erythematosus— A chronic autoimmune disease that affects the skin, joints, and certain internal organs.

Pancreas— A gland located near the liver, the pancreas produces enzymes and fluids that help to breakdown food. It also produces the hormone insu-in that the body must have to utilize sugar (glucose).

Potassium— A mineral found in whole grains, meat, legumes, and some fruits and vegetables. Potassium is important for many body processes, including proper functioning of nerves and muscles.

Triglyceride— A substance formed in the body from the breakdown of fat in the diet. Triglycerides are the main fatty materials in the blood. Triglyceride levels are important in the diagnosis and treatment of many diseases, including high blood pressure, diabetes, and heart disease.

Some nonprescription (over-the-counter, OTC) medicines and herbal remedies also function as diuretics. However, the drugs described here cannot be bought without a physician’s prescription. They are available in tablet, capsule, liquid, and injectable forms.

Recommended dosage

The recommended dosage depends on the type of diuretic, the condition it treats, and the individual’s size, age, and health. Patients should check with the physician who prescribed the drug or the pharmacist who filled the prescription for the correct dosage and then take the medicine exactly as directed.

Precautions

Seeing a physician regularly while taking a diuretic is important. The physician may order blood work and will do a physical examination to make sure the diuretic is working as it should without unwanted side effects.

For patients taking a class of diuretic that can cause large amounts of potassium to be excreted, physicians may recommend adding potassium-rich foods such as bananas to the diet, and they may suggest taking a daily potassium supplement. If the physician recommends any of these measures, the patient must make sure to closely follow the directions. The patient should not make other significant diet changes or take any dietary supplements without checking with the physician. People who are taking potassium-sparing diuretics should not add potassium to their diets, as too much potassium may be harmful.

Patients taking potassium-sparing diuretics should know the signs of too much potassium and should check with a physician as soon as possible if any of these symptoms occur, including:

• irregular heartbeat
• breathing problems
• numbness or tingling in the hands, feet, or lips
• confusion or nervousness
• unusual tiredness or weakness
• weak or heavy feeling in the legs

Patients taking diuretics that cause potassium loss should know the signs of too little potassium and should check with a physician as soon as possible if they have any of these symptoms, including:

• fast or irregular heartbeat
• weak pulse
• nausea or vomiting
• dry mouth
• excessive thirst
• muscle cramps or pain
• unusual tiredness or weakness
• mental or mood changes

People who become ill with gastrointestinal diseases while taking diuretics may lose too much water or potassium if they have severe vomiting and diarrhea.

Diuretics drugs make some people feel lightheaded, dizzy, or faint when they get up after sitting or lying down. Older people are especially likely to have this problem. Drinking alcohol, exercising, standing for long periods, or being outdoors in hot weather may make the problem worse. To lessen this problem, a person should get up gradually and hold onto something for support if possible. The patient should avoid or limit the amount of alcohol he or she drinks and be careful in hot weather or when exercising or standing for a long time.

People who take a diuretic should tell the healthcare professional before having surgical or dental procedures, medical tests, or emergency treatment.

Special conditions

People who have certain medical conditions or who are taking certain other drugs may encounter problems if they take diuretics. Before taking diuretic drugs, they should be sure to let the physician know about these conditions.

ALLERGIES. Anyone who has had unusual reactions to diuretics or sulfonamides (sulfa drugs) in the past should let the physician know. The physician should also be told about any allergies to foods, dyes, preservatives, or other substances.

PREGNANCY. Diuretics will not help the swelling of hands and feet that some women experience during pregnancy. Pregnant women should not use diuretics unless prescribed by their obstetrician or other physician. Although studies have not been done on pregnant women, studies of laboratory animals show that some diuretics can cause harmful effects when taken during pregnancy.

BREASTFEEDING. Some diuretics pass into breast milk, but no reports exist of problems in nursing babies whose mothers use this medicine. However, thiazide diuretics may decrease the flow of breast milk. Women who are breastfeeding and need to use a diuretic should check with the physician.

OTHER MEDICAL CONDITIONS . Side effects of some diuretics may be more likely in people who have had a recent heart attack or who have liver disease or severe kidney (renal) disease. Other types of diuretics may not work properly in people with liver disease or kidney disease. Diuretics may worsen certain medical conditions such as gout, kidney stones, pancreatitis, lupus erythematosus, and hearing problems. In addition, people with diabetes should be aware that a diuretic may increase blood sugar levels. People with heart or blood vessel disease should know that some diuretic increase cholesterol or triglyceride levels. The risk of an allergic reaction to certain diuretics is greater in people with bronchial asthma. Before using diuretics, people with any of these medical conditions should make their physicians aware of their medical history. Also, people who have trouble urinating or who have high blood levels of potassium may not be able to take diuretics and should discuss these conditions with their physician before using them.

Side effects

Some people feel unusually tired when they first start taking diuretics. This effect usually becomes lessnoticeable over time, as the body adjusts to the medicine. Other side effects, such as loss of appetite, nausea, vomiting, stomach cramps, diarrhea, and dizziness, usually lessen or go away as the body adjusts to the diuretic drug. These problems usually do not nee medical attention unless they continue or interfere with normal activities.

Some diuretics make the skin more sensitive to sunlight. Even brief exposure to sun can cause severe sunburn, itching, a rash, redness, or other changes in skin color. While being treated with this medicine, the person should avoid being in direct sunlight; wear a hat and tightly woven clothing that covers the arms and legs; use a sunscreen with a skin protection factor (SPF) of at least 15; protect the lips with a sun-block lipstick; and not use tanning beds, tanning booths, or sunlamps. People with fair skin may need to use a sunscreen with a higher SPF.

Because diuretics increase urine output, people who take this medicine may need to urinate more often, even during the night. Healthcare professionals can help patients schedule their doses to avoid interfering with their sleep or regular activities.

Interactions

Diuretics may interact with other drugs, herbs, or dietary supplements. When this occurs, the effects of one or both of the drugs become either more or less effective or the risk of side effects may increase. Anyone who takes a diuretic should inform the healthcare providers about all other prescription and over-the-counter drugs, herbs, and dietary supplements that he or she is taking in order to avoid harmful interactions.

Some common drugs that may interact with diuretics include:

• Angiotensin-converting enzyme (ACE) inhibitors such as benazepril (Lotensin), captopril (Capoten), and enalapril (Vasotec), which are used to treat high blood pressure. Taking these drugs with potassium-sparing diuretics may cause levels of potassium in the blood to be too high, increasing the chance of side effects.
• Cholesterol-lowering drugs such as cholestyramine (Questran) and colestipol (Colestid). Taking these drugs with combination diuretics such as Dyazide and Maxzide may keep the diuretic from working. The person should take the diuretic at least one hour before or four hours after the cholesterol-lowering drug.
• Cyclosporine (Sandimmune), a drug that suppresses the immune system. Taking this medicine with potassium-sparing diuretics may increase the chance of side effects by causing levels of potassium in the blood to be too high.
• Potassium supplements, other drugs or supplements containing potassium, or salt substitutes that contain potassium. Taking these with potassium-sparing diuretics may lead to too much potassium in the blood, increasing the chance of side effects.
• Lithium, used to treat bipolar disorder (manic-depressive illness). Using this medicine with potassium-sparing diuretics may allow lithium to build up to poisonous levels in the body.
• Digitalis, also called digoxin (Lanoxin) or digitoxin. Using this medicine with combination diuretics such as triamterene-hydrocholorthiazide (Dyazide, Max-zide) increases the chance of irregular heartbeat.

The list above does not include every drug or herb that may interact with diuretics. The patient should check with a physician or pharmacist before combining diuretics with any other prescription or over-the-counter drugs, herbal medicines, or dietary supplements.

Resources

BOOKS

Rubin, Alan L. High Blood Pressure for Dummies 2nd ed. Indianapolis, IN: Wiley Pub., 2007.

ORGANIZATIONS

American Heart Association. 7272 Greenville Avenue, Dallas, TX 75231. (800) 242-8721. http://www.americanheart.org (accessed March 19, 2008).

OTHER

Anaizi, Nasr “Diuretics.” The Drug Monitor [cited January 3, 2008]. http://www.thedrugmonitor.com/diuretics.html (accessed March 19, 2008).

“Diuretics.” Mayo Clinic. December 22, 2006 [cited January 3, 2008]. http://www.mayoclinic.com/health/diuretics/HI00030 (accessed March 19, 2008).

“Diuretics Key Factor in Preventing Heart Failure.” American Heart Association. May 1, 2006 [cited January 3, 2008]. http://www.americanheart.org/presenter.jhtml?identifier=3039311 (accessed March 19, 2008).

Nancy Ross-Flanigan

Sam Uretsky, PharmD

Tish Davidson, AM

Diverticulectomy seeMeckel’s diverticulectomy

Diuretics

Definition

Diuretics are medicines that help reduce the amount of water in the body.

Purpose

Diuretics are used to treat the buildup of excess fluid in the body that occurs with some medical conditions such as congestive heart failure, liver disease, and kidney disease. Some diuretics are also prescribed to treat high blood pressure. These drugs act on the kidneys to increase urine output. This reduces the amount of fluid in the bloodstream, which in turn lowers blood pressure.

Description

There are several types of diuretics, also called water pills:

• Loop diuretics, such as bumetanide (Bumex) and furosemide (Lasix), get their name from the loopshaped part of the kidneys where they have their effect.
• Thiazide diuretics include such commonly used diuretics as hydrochlorothiazide (HydroDIURIL, Esidrix), chlorothiazide (Diuril), and chlorthalidone (Hygroton).
• Potassium-sparing diuretics prevent the loss of potassium, which is a problem with other types of diuretics. Examples of potassium-sparing diuretics are amiloride (Midamor) and triamterene (Dyrenium).

In addition, some medicines contain combinations of two diuretics. The brands Dyazide and Maxzide, for example, contain the thiazide diuretic hydrochlorothiazide with the potassium-sparing diuretic triamterene.

Some nonprescription (over-the-counter) medicines contain diuretics. However, the medicines described here cannot be bought without a physician's prescription. They are available in tablet, capsule, liquid, and injectable forms.

Recommended dosage

The recommended dosage depends on the type of diuretic and may be different for different patients. Check with the physician who prescribed the drug or the pharmacist who filled the prescription for the correct dosage, and take the medicine exactly as directed.

Precautions

Seeing a physician regularly while taking a diuretic is important. The physician will check to make sure the medicine is working as it should and will watch for unwanted side effects.

Some people feel unusually tired when they first start taking diuretics. This effect usually becomes less noticeable over time, as the body adjusts to the medicine.

Because diuretics increase urine output, people who take this medicine may need to urinate more often, even during the night. Health care professionals can help patients schedule their doses to avoid interfering with their sleep or regular activities.

For patients taking the kinds of diuretics that rob potassium from the body, physicians may recommend adding potassium-rich foods or drinks, such as citrus fruits and juices, to the diet. Or they may suggest taking a potassium supplement or taking another medicine that keeps the body from losing too much potassium. If the physician recommends any of these measures, be sure to closely follow his or her directions. Do not make other diet changes without checking with the physician. People who are taking potassium-sparing diuretics should not add potassium to their diets, as too much potassium may be harmful.

People who take diuretics may lose too much water or potassium when they get sick, especially if they have severe vomiting and diarrhea. They should check with their physicians if they become ill.

These medicines make some people feel lightheaded, dizzy, or faint when they get up after sitting or lying down. Older people are especially likely to have this problem. Drinking alcohol, exercising, standing for long periods, or being in hot weather may make the problem worse. To lessen the problem, get up gradually and hold onto something for support if possible. Avoid drinking too much alcohol and be careful in hot weather or when exercising or standing for a long time.

Anyone who is taking a diuretic should be sure to tell the health care professional in charge before having surgical or dental procedures, medical tests, or emergency treatment.

Some diuretics make the skin more sensitive to sunlight. Even brief exposure to sun can cause a severe sunburn, itching, a rash, redness, or other changes in skin color. While being treated with this medicine, avoid being in direct sunlight, especially between 10 a.m. and 3 p.m.; wear a hat and tightly woven clothing that covers the arms and legs; use a sunscreen with a skin protection factor (SPF) of at least 15; protect the lips with a sun block lipstick; and do not use tanning beds, tanning booths, or sunlamps. People with fair skin may need to use a sunscreen with a higher skin protection factor.

Special conditions

People who have certain medical conditions or who are taking certain other medicines may have problems if they take diuretics. Before taking these drugs, be sure to let the physician know about any of these conditions:

ALLERGIES. Anyone who has had unusual reactions to diuretics or sulfonamides (sulfa drugs) in the past should let his or her physician know before using a diuretic. The physician should also be told about any allergies to foods, dyes, preservatives, or other substances.

PREGNANCY. Diuretics will not help the swelling of hands and feet that some women have during pregnancy. In general, pregnant women should not use diuretics unless a physician recommends their use. Although studies have not been done on pregnant women, studies of laboratory animals show that some diuretics can cause harmful effects when taken during pregnancy.

BREASTFEEDING. Some diuretics pass into breast milk, but no reports exist of problems in nursing babies whose mothers use this medicine. However, thiazide diuretics may decrease the flow of breast milk. Women who are breastfeeding and need to use a diuretic should check with their physicians.

OTHER MEDICAL CONDITIONS. Side effects of some diuretics may be more likely in people who have had a recent heart attack or who have liver disease or severe kidney disease. Other diuretics may not work properly in people with liver disease or severe kidney disease. Diuretics may worsen certain medical conditions, such as gout, kidney stones, pancreatitis, lupus erythematosus, and hearing problems. In addition, people with diabetes should be aware that diuretics may increase blood sugar levels. People with heart or blood vessel disease should know that some diuretics increase cholesterol or triglyceride levels. The risk of an allergic reaction to certain diuretics is greater in people with bronchial asthma. Before using diuretics, people with any of these medical problems should make sure their physicians are aware of their conditions. Also, people who have trouble urinating or who have high potassium levels in their blood may not be able to take diuretics and should check with a physician before using them.

USE OF CERTAIN MEDICINES. Taking diuretics with certain other drugs may affect the way the drugs work or may increase the chance of side effects.

Side effects

Some side effects, such as loss of appetite, nausea and vomiting, stomach cramps, diarrhea, and dizziness, usually lessen or go away as the body adjusts to the medicine. These problems do not need medical attention unless they continue or interfere with normal activities.

Patients taking potassium-sparing diuretics should know the signs of too much potassium and should check with a physician as soon as possible if any of these symptoms occur:

• irregular heartbeat
• breathing problems
• numbness or tingling in the hands, feet, or lips
• confusion or nervousness
• unusual tiredness or weakness
• weak or heavy feeling in the legs

Patients taking diuretics that cause potassium loss should know the signs of too little potassium and should check with a physician as soon as possible if they have any of these symptoms:

• fast or irregular heartbeat
• weak pulse
• nausea or vomiting
• dry mouth

• excessive thirst
• muscle cramps or pain
• unusual tiredness or weakness
• mental or mood changes

Interactions

Diuretics may interact with other medicines. When this happens, the effects of one or both of the drugs may change or the risk of side effects may be greater. Anyone who takes a diuretic should let the physician know all other medicines he or she is taking and should ask whether the possible interactions can interfere with drug therapy. Among the drugs that may interact with diuretics are:

• Angiotensin-converting enzyme (ACE) inhibitors, such as benazepril (Lotensin), captopril (Capoten), and enalapril (Vasotec), used to treat high blood pressure. Taking these drugs with potassium-sparing diuretics may cause levels of potassium in the blood to be too high, increasing the chance of side effects.
• Cholesterol-lowering drugs such as cholestyramine (Questran) and colestipol (Colestid). Taking these drugs with combination diuretics such as Dyazide and Maxzide may keep the diuretic from working. Take the diuretic at least one hour before or four hours after the cholesterol-lowering drug.
• Cyclosporine (Sandimmune), a medicine that suppresses the immune system. Taking this medicine with potassium-sparing diuretics may increase the chance of side effects by causing levels of potassium in the blood to be too high.
• Potassium supplements, other medicines containing potassium, or salt substitutes that contain potassium. Taking these with potassium-sparing diuretics may lead to too much potassium in the blood, increasing the chance of side effects.
• Lithium, used to treat bipolar disorder (manicdepressive illness). Using this medicine with potassium-sparing diuretics may allow lithium to build up to poisonous levels in the body.
• Digitalis heart drugs, such as digoxin (Lanoxin). Using this medicine with combination diuretics such as triamterene-hydrocholorthiazide (Dyazide, Maxzide) may cause blood levels of the heart medicine to be too high, making side effects such as changes in heartbeat more likely.

The list above does not include every drug that may interact with diuretics. Check with a physician or pharmacist before combining diuretics with any other prescription or nonprescription (over-the-counter) medicine.

KEY TERMS

Inflammation— Pain, redness, swelling, and heat that usually develop in response to injury or illness.

Lupus erythematosus— A chronic disease that affects the skin, joints, and certain internal organs.

Pancreas— A gland located beneath the stomach. The pancreas produces juices that help break down food.

Potassium— A mineral found in whole grains, meat, legumes, and some fruits and vegetables. Potassium is important for many body processes, including proper functioning of the nerves and muscles.

Triglyceride— A substance formed in the body from fat in the diet. Triglycerides are the main fatty materials in the blood. Together with protein, they make up high- and low-density lipoproteins (HDLs and LDLs). Triglyceride levels are important in the diagnosis and treatment of many diseases including high blood pressure, diabetes, and heart disease.