Paroxetine is an anti-depressant drug that affects the chemicals that nerves in the brain use to communicate with one another. These chemical messengers called neurotransmitters are released by one nerve and taken up by other nerves. Neurotransmitters that are released but not taken up by other nerves are taken up by the nerves that release them reuptake. Many experts believe that it is an imbalance among the amounts of the different neurotransmitters that are released that causes depression. Paroxetine works by inhibiting the reuptake of serotonin by the nerves that release it an action which allows more serotonin to be available to be taken up by other nerves. Paroxetine is in a class of drugs called selective serotonin reuptake inhibitors SSRIs a class that also contains fluoxetine Prozac and sertraline Zoloft.

Paroxetine is given as a single daily dose usually in the morning. As with all anti-depressants the full effect may not occur until after a few weeks of therapy. Doses for obsessive- compulsive disorders and panic disorders are often higher than those for depression. Doses often are adjusted to find the optimal dose. Elderly patients debilitated persons and patients with certain kidney or liver diseases may need lower doses because they metabolize and eliminate paroxetine more slowly and therefore are prone to develop high blood levels.

The most commonly noted side effects associated with paroxetine are anxiety sweating nausea decreased appetite somnolence sleepiness dizziness insomnia and male sexual disturbances. Dry mouth occurs in about 18 of patients taking paroxetine.

The withdrawal of treatment with many anti-depressants has been associated with troublesome symptoms. Symptoms have been particularly frequent with anti-depressants like paroxetine classified as SSRIs. Specifically the incidence of symptoms upon withdrawal is between 17 and 30 with paroxetine and fluvoxamine Luvox but less than 5 with other SSRIs.

The most common symptoms of withdrawal have been dizziness tiredness tingling of the extremities nausea vivid dreams irritability and poor mood. Other symptoms have included visual disturbances and headaches.

Withdrawal reactions have been reported upon withdrawing SSRIs after an average of 12 to 36 weeks of treatment but after as few as 5 weeks. Although most authorities have recommended that treatment be discontinued by tapering the SSRI by gradually reducing the dose symptoms have occurred despite tapering. Symptoms generally appear within a few days of discontinuing medication and persist for an average of 12 days up to 21 days. They are relieved within 24 hours by re-administering the medication that was discontinued.

It has been suggested that SSRIs may cause depression to worsen and even lead to suicide in a small number of patients. These potential side effects are difficult to evaluate in depressed patients because depression can progress with or without treatment and suicide is itself a consequence of depression. Moreover the evidence supporting these potential side effects is weak. Therefore no conclusions can yet be drawn about the relationship between SSRIs and worsening depression and suicide. Until better information is available patients receiving SSRIs should be monitored for worsening depression and suicidal tendencies.

All SSRIs including paroxetine should not be taken with any of the MAO mono-amine oxidase inhibitor-class of anti-depressants for example isocarboxazid Marplan phenelzine Nardil tranylcypromine Parnate and procarbazine Matulane. Such combinations may lead to confusion high blood pressure tremor and increased activity. This same type of interaction may also occur with selegiline Eldepryl fenfluramine Pondimin and dexfenfluramine Redux. The anti-ulcer medication cimetidine Tagamet can increase the amount of paroxetine in the blood possibly leading to side effects. Paroxetine may increase the risk of bleeding in patients taking warfarin Coumadin although the mechanism for the interaction is not known. Tryptophan can cause headaches nausea sweating and dizziness when taken with any SSRI. Phenytoin Dilantin and phenobarbital may decrease the amount of paroxetine in the body and possibly reducing its effectiveness.

Paxil CR is approved for continuous or intermittent therapy for premenstrual dysphoric disorder. For intermittent therapy women take Pacil CR once daily during only the two-week period prior to the onset of their menstrual cycle rather than throughout the month.

Paroxetine is indicated for the management of depression obsessive-compulsive disorders panic disorders and premenstrual dysphoric disorder.

Paroxetine is also used occasionally to treat headaches diabetic leg pain and premature ejaculation. Talk to your doctor about the possible risks of using this drug for your condition. This medication may be prescribed for other uses ask your doctor or pharmacist for more information.

Tablets should be kept at room temperature 15- 30°C 59-86°F.