Paxil and Paxil CR
Paxil and Paxil CR
Definition
Paxil is an antidepressant drug belonging to the class of antidepressants known as selective serotonin reuptake inhibitors (SSRIS). It is used to treat depression , generalized anxiety disorder , social anxiety disorder, panic disorder , obsessive compulsive disorder, and posttraumatic stress disorder in adults. Paxil CR is a controlled-release formulation of Paxil, meaning it is formulated to deliver its dose slowly throughout the day.
Purpose
Paxil and Paxil CR are antidepressants used to relieve a variety of mood disorders. These medicine may be used to treat serious, ongoing depression and other conditions such as social and generalized anxiety disorders, panic disorders, obsessive-compulsive disorder (OCD), posttraumatic stress disorder (PTSD), and premenstrual dysphoric disorder (PMDD), a serious form of premenstrual syndrome .
Sometimes a health care provider will prescribe Paxil or Paxil CR for conditions other than the approved ones listed on the drug’s label. This is called off-label use. Off-label uses for Paxil and Paxil CR include the treatment of certain headaches, hot flashes due to menopause, premature ejaculation , and nerve problems due to diabetes (diabetic neuropathy).
Specifically, Paxil and Paxil CR belong to a class of medicines called selective serotonin reuptake inhibitors (SSRIs ). SSRIs are drugs that help increase the activity of a natural chemical in the brain called serotonin. Serotonin helps send messages between nerves in the brain. It is believed that these messages play a role in determining a person’s mood.
Description
The active ingredient in Paxil and Paxil CR is a compound called paroxetine hydrochloride. Paxil and Paxil CR are brand names. Paroxetine hydrochloride is the drug’s generic name.
The compound is an odorless, off-white powder that the manufacturer forms into a regular tablet, controlled-release (CR) tablet, or liquid, also called an oral suspension. The liquid has an orange taste and color. Tablet color depends on how much medicine it contains. For example, a 10-mg tablet is yellow, a 20-mg tablet is pink, 30-mg tablet is blue, and 40-mg tablet is green.
The 10-mg and 20-mg tablets are scored with a line across the middle that makes it easy to cut the pill in half. Paxil CR contains the same type of medicine as original Paxil, but it is created in a way that controls how fast the body absorbs the drug. One pill slowly releases medicine into the body throughout the entire day.
Recommended dosage
The tablets are usually taken in the morning. Taking them with food may help reduce certain side effects. Paxil CR tablets must be swallowed whole. The medicine should not be crushed or chewed. The Paxil CR tablets are coated with a hard film that slowly dissolves, controlling the amount of drug that is released into the body over time.
The exact dosage a person needs depends on the condition being treated, as well as coexisting health conditions and medication history. Certain conditions may require many months of therapy, whereas others do not. The general dosage range for specific conditions is outlined as follows:
Generalized anxiety disorder
- Paxil: 20-50 mg/day
Major depression
- Paxil: 20-50 mg/day
- Paxil CR: 25-62.5 mg/day
Obsessive-compulsive disorder (OCD)
- Paxil: 20 mg/day at first; may be slowly increased by 10 mg/day; maximum dosage is 60 mg/day
Panic disorder
- Paxil: 10-60 mg/day
- Paxil CR: 12.5-75 mg/day
Premenstrual dysphoric disorder (PMDD)
- Paxil: 20-60 mg/day or only during certain times a month
Posttraumatic stress disorder (PTSD)
- Paxil: 20-50 mg/day
Social anxiety disorder
- Paxil: 20-60 mg/day
- Paxil CR: 12.5-37.5 mg/day
Precautions
Pregnant women
Pregnant women should use caution if taking Paxil or Paxil CR. The U.S. Food and Drug Administration (FDA) has warned that taking the drug during the first three months of pregnancy may increase the risk for birth defects. The FDA classifies a drug according to how it may affect a baby during pregnancy and breastfeeding. Paxil or Paxil CR now fall into pregnancy category D, the government’s second highest category for risk of birth defects. This means that studies have shown that the drug causes harm to an unborn human baby, but the drug’s benefits to the mother may outweigh the risks. The manufacturer of Paxil and Paxil CR reports that taking paroxetine during the last three months of pregnancy has been shown to cause health problems in babies after birth. Such problems include breathing difficulties, seizures, poor feeding, changes in body temperature, vomiting, low blood sugar, floppiness, stiffness, tremor, shakiness, irritability, and constant crying. Paxil moves through breast milk, so breastfeeding mothers could pass the drug to their babies. Women who take Paxil and are pregnant, breastfeeding, or planning to become pregnant should talk to their health care providers. An alternate antidepressant may be recommended.
Children and young adults
In October 2004, the FDA required that manufacturers of Paxil, Paxil CR, and all other antidepres-sants include a warning on the medicine’s label telling users that the drugs have been linked to an increase in suicidal thought and actions in children and young adults. This is called a “black box warning.” As of January 2007, Paxil is not approved for persons under age 18.
Older adults
Older adults tend to metabolize (break down) drugs more slowly than younger people. Therefore, older and elderly adults may need lower doses of Paxil or Paxil CR than younger patients.
Medical conditions
Before taking Paxil or Paxil CR, patients should make sure their health care provider also knows if they have or have had any of the following conditions:
- electroconvulsive therapy (ECT)
- heart disease
- kidney disease
- liver disease
- seizures
- suicidal thoughts or suicide attempt
Side effects
Nausea is one of the most common side effects of Paxil or Paxil CR. Taking the medicine with food may help relieve stomach discomfort. Other reported side effects involving the gastrointestinal tract include dry mouth, constipation, diarrhea, decreased appetite, an eating disorder called anorexia, gas (flatulence), and vomiting.
Although the drug is used to treat certain anxiety disorders, in some cases it may also cause anxiety and related symptoms, such as heart palpitations and nervousness. This side effect may be reduced by starting with the lowest dosage and increasing it gradually, if needed.
Other side effects of Paxil or Paxil CR include abnormal vision, dizziness, injury due to dizziness, infection, frequent urination, headache, sweating, tremor, trouble falling or staying asleep (insomnia), sleepiness, weakness, and yawning. Sexual side effects have been reported. Men taking Paxil or Paxil CR may have delayed ejaculation.
Interactions
People who take or have recently taken antidepressant medicines called monoamine oxidase inhibitors (MAOIs) should use caution when taking Paxil or Paxil CR. MAOIs cause the body to absorb too much paroxetine, which could be dangerous. Patients must wait 14 days before taking Paxil after discontinued use
KEY TERMS
Ejaculation —The release of sperm-containing fluid from the penis.
Hot flashes —Body-wide feelings of warmth and flushing.
Menopause —The time of life after a woman’s menstrual cycle permanently stops.
Monoamine oxidase inhibitors (MAOIs) —The oldest class of antidepressants. Types of MAOIs include phenelzine (Nardil), tranylcypromine (Parnate), iso-carboxazid (Marplan), and selegiline (Emsam).
Selective serotonin reuptake inhibitor (SSRI) —An antidepressant drug that controls the balance of serotonin in the body.
Serotonin —A chemical found in the brain and other parts of the body that helps regulate mood.
of an MAOI. The same amount of time should lapse when stopping Paxil and starting an MAOI. Kidney and liver disease can also cause increased blood levels of paroxetine. Because of this, dosages may need to be reduced in patients with severe liver or kidney disease.
If Paxil or Paxil CR is taken with another SSRI, a life-threatening drug reaction called “serotonin syndrome” may develop. Symptoms occur within minutes to hours and may include high blood pressure, mental status changes, and increased body temperature (hyperthermia).
Paxil or Paxil CR may slow down or speed up the absorption of many other drugs. The following drugs are known to interact with Paxil (Paxil CR):
- atomoxetine (Strattera)
- cimetidine (Tagamet)
- desipramine (Norpramin)
- digoxin (Lanoxin, Digitek)
- phenytoin (Dilantin)
- procyclidine (Kemadrin)
- risperidone (Risperdal)
- St. John’s wort
- warfarin (Coumadin)
Resources
BOOKS
Ferri, Fred F. Practical Guide to the Care of the Medical Patient. 6th ed. St. Louis: Mosby, 2004.
Karch, Amy M. 2007 Lippincott’s Nursing Drug Guide. Baltimore, MD: Lippincott Williams & Wilkins, 2007.
Reus, Victor I. “Practical Guide to the Care of the Medical Patient.” Principles of Internal Medicine. 16th ed. New York, NY: McGraw-Hill, 2005.
ORGANIZATIONS
Mental Health America, 2000 N. Beauregard Street, 6th Floor. Alexandria, VA 22311. (800) 969-6MHA (6642) http://www.nmha.org
National Alliance on Mental Illness, 2107 Wilson Boulevard, Suite 300, Arlington, VA 22201-3042. (703) 524-7600. http://www.nami.org
National Institute of Mental Health, 6001 Executive Boulevard, Room 8184, MSC 9663, Bethesda, MD 20892-9663. (301) 443-4513. http://www.nimh.nih.gov
Kelli Miller Stacy