Paroxetine: current status in psychiatry.

Paroxetine is a selective serotonin reuptake inhibitor (SSRI) with antidepressant and anxiolytic properties. It is commercially available in both an immediate-release (paroxetine) and a controlled-release formulation (paroxetine CR). The latter product was developed to improve gastrointestinal tolerability. Paroxetine is the most potent inhibitor of the reuptake of serotonin among the available SSRIs. It has approved indications for the treatment of major depression, obsessive-compulsive disorder, panic disorder, generalized anxiety disorder, post-traumatic stress disorder and social phobia in adults. Paroxetine CR is approved for the treatment of major depression, social anxiety disorder, panic disorder and premenstrual dysphoric disorder in adults. While the overall efficacy of paroxetine appears to be comparable with other SSRIs in the treatment of major depression, it is approved for use in a wider variety of anxiety disorders than any other antidepressant. Long-term data suggest that paroxetine is effective in preventing relapse or recurrence of depression for up to 1 year. Limited data show that paroxetine maintains a therapeutic response over 1 year in obsessive-compulsive disorder and up to 6 months in panic disorder. The side-effect profile of paroxetine is largely similar to that of the other SSRIs, although paroxetine tends to be more sedating and constipating in some patients, perhaps due to its anticholinergic activity. The potential for discontinuation syndrome and weight gain appears to be slightly higher with paroxetine than with other SSRIs. This review focuses on the immediate release and controlled-release formulations of paroxetine. It summarizes the efficacy and tolerability data for both formulations, with a particular emphasis on paroxetine CR which was introduced in 2002. It also discusses emerging evidence in other clinical areas and recent data that have led to modifications in the safety profile of paroxetine.