What is Paxil?

Paxil (paroxetine hydrochloride), a new antidepressant medication, was introduced into the United States in early 1993. It is a member of the SSRI (selective serotonin reuptake inhibitor) family (along with Zoloft and Prozac). These new 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).

What does Paxil treat?

Depression is a biologically based disorder, although social and genetic factors may contribute to the illness. Depression is associated with a decreased number 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, low blood pressure, or weight changes. Paxil has no active metabolites and leaves one's system 24 hours after it enters. SmithKline Beecham Pharmaceuticals, which makes Paxil, states that Paxil is the most selective of the SSRI antidepressants. This selectivity causes serotonin levels in the brain to normalize quickly, relieving depression with relatively few side effects.

Who can benefit from taking Paxil?

Paxil is equally effective in elderly depressed patients as it is in younger. Elderly people may turn to Paxil for relief because it does not cause significant changes in blood pressure, unlike Effexor and some other antidepressants.

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 20 mg tablets (pink) or 30 mg tablets (blue). 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.

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 and those taking lithium should take Paxil with caution. Other combinations of medications require consultation with your doctor. Alcohol consumption is best avoided while one is taking Paxil.

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. Side effects may include drowsiness, asthenia (lack of physical strength) tremors, nervousness, dizziness, insomnia, sweating, ejaculatory delay, and other male genital dysfunction. There may be a slight weight loss associated with Paxil. Only a small percentage of people have had to discontinue their use of Paxil because of side effects.

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?

Most 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 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.

Is there financial assistance available to those who cannot afford treatment with Paxil?

The Paxil Access to Care program allows a physician to arrange no-cost supplies of Paxil for patients who meet specific requirements. To be eligible, a patient must have an annual household income of less than $25,000, have no medical insurance, and be ineligible for government (such as Medicaid) or private programs covering prescriptions. A physician who believes that the cost of Paxil would pose a significant hardship on a patient or cause an inability to take the medication as prescribed can call 1-800-729-4544 to receive a Paxil Access to Care kit.

Reviewed by Elliot Gershon, M.D., Chief, Clinical Neurogenetics Branch, NIMH 3/95