Efficacy and Tolerability of Paroxetine for the Long-Term Treatment of Generalized Anxiety Disorder

Background: Paroxetine has demonstrated efficacy in depression and anxiety disorders, including generalized anxiety disorder (GAD). This 32-week study evaluated the maintained efficacy and safety of paroxetine in GAD by assessing the potential for relapse after discontinuation of medication.

Method: Adults (N = 652) with DSM-IV GAD and a Clinical Global Impressions-Severity of Illness (CGI-S) score >= 4 received paroxetine (20-50 mg/day) for 8 weeks. Patients whose CGI-S score had decreased by at least 2 points to = 4 or withdrawal resulting from lack of efficacy) during double-blind treatment.

Results: Significantly fewer paroxetine than placebo patients relapsed during the 24-week double-blind phase (10.9% vs. 39.9%; p < .001). Placebo patients were almost 5 times more likely to relapse than paroxetine patients (estimated hazard ratio = 0.213 [95% CI = 0.1 to 0.3]; p < .001). Statistical significance in favor of paroxetine was demonstrated for all secondary efficacy parameters, including functional status. Twice as many paroxetine patients as placebo patients (73%) achieved remission. Paroxetine was well tolerated, with no unexpected adverse events reported.

Conclusion: Paroxetine was found to be effective and well tolerated for both the short- and long-term treatment of DSM-IV GAD. Continued treatment with paroxetine significantly reduced the potential for relapse of GAD symptoms.