Resources - Medications
Paxil (paroxetine)
What is Paxil?
Paxil (paroxetine hydrochloride) and Paxil CR are antidepressant medications also used to treat anxiety disorders. Paxil was introduced into the United States in early 1993. They are members of the SSRI (selective serotonin reuptake inhibitor) family (along with Zoloft and Prozac). These medications are effective in alleviating the symptoms of major depression without causing some of the harmful side effects caused by the older tricyclic antidepressants (TCAs). Paxil is also approved for the treatment of anxiety disorders, including generalized anxiety disorder (GAD), panic disorder, post-traumatic stress disorder (PTSD), social anxiety disorder, and obsessive-compulsive disorder (OCD).
What does Paxil treat?
Depression and anxiety disorders are biologically based disorders, although social factors may contribute to these illnesses. Depression is associated with decreased activity of neurotransmitters in the brain (particularly serotonin and norepinephrine). These chemical messengers help regulate several functions and thoughts, including mood. Paxil blocks the reabsorption of serotonin and normalizes the brain's chemical supply.
What are the advantages of Paxil over other antidepressants?
Paxil is as effective in relieving depression as TCAs such as imipramine. However, Paxil causes fewer adverse cardiovascular and anticholinergic effects (dry mouth, constipation, blurred vision, urinary retention) than the older TCAs. It does not usually cause drowsiness or low blood pressure. Paxil has no active metabolites and leaves one's system 24 hours after it enters.
Who can benefit from taking Paxil?
Paxil is equally effective in elderly depressed patients as it is in younger patients. Paxil is effective in the treatment of anxiety which accompanies depression in some people. Those experiencing lethargy at the beginning of treatment can also take Paxil with positive results because Paxil does not impair psychomotor function.
What is the standard dose of Paxil?
The usual dose of Paxil is 20 mg taken once daily, usually in the morning. Paxil comes in either 10 mg tablets and 40 mg tablets. For the depressed elderly, the recommended starting dose is 10 mg once daily. Physicians may change the dose by 10 mg at a time and the dose should not exceed 50 mg per day (40 mg in geriatric patients). There should be a one-week interval between dose adjustments. The dose of Paxil for the anxiety disorders is generally the same as for depression, except that for patients with panic disorder it is recommended to start at 10 mg. Consumers with panic disorder often need to take 40 mg a day to feel better.
Can I take Paxil with other medications?
Paxil should not be used while taking any MAOI (monoamine oxidase inhibitor) medication. The interaction between the two could produce fatal results. Therefore, there should be a fourteen-day interval between stopping the MAOI and starting Paxil, or vice versa.
Patients with kidney or liver dysfunction should take Paxil with caution. Other combinations of medications require consultation with your doctor. Alcohol consumption is best avoided while one is taking Paxil. There are some potentially problematic interactions between Paxil and other drugs such as tricyclic antidepressants and beta-blockers.
What are the most common side effects of Paxil?
For the most part, the side effects of Paxil are mild and brief. The major side effect of Paxil is nausea, which can be reduced by taking Paxil with food. Paxil CR has a lower risk of nausea than Paxil. Side effects may include drowsiness, asthenia (lack of physical strength) tremors, nervousness, dizziness, insomnia, weight gain, sweating, ejaculatory delay, and other male genital dysfunction. Only a small percentage of people have had to discontinue their use of Paxil because of side effects. Both men and women commonly experience difficulty having an orgasm while on Paxil. Also, patients who stop taking Paxil abruptly often experience dizziness, nausea, vertigo and shock-like sensations. Therefore, slow tapering is recommended.
Women who become pregnant or who are nursing an infant should discuss with their doctors the effects of Paxil. People with kidney or liver dysfunction should use Paxil with caution.
How soon will I feel better?
Some people will notice improvements within a week or two, but it may take up to six weeks for the full therapeutic effect to be realized. Depressed mood, concentration problems, and slowed activity may improve in the first week, sleep disturbances within the second week.
How long should I stay on Paxil?
Paxil should be continued as directed by the prescribing physician. Paxil is effective in the treatment of both short-term and long-term depression, and it can be beneficial in preventing relapse into depression. Studies have shown that Paxil is easily tolerated for up to four years. It is important to be in close communication with the prescribing physician, and to promptly report any unusual or distressing symptoms or side effects.
Reviewed by Jack Gorman, M.D., Chair NAMI Scientific Council, Sept 2002
Information from NAMI's Website (http://www.nami.org)
