This randomized, double-blind clinical trial involving 198 generalized anxiety disorder (GAD) patients was conducted to more clearly define gepirone's role for the treatment of anxiety in daily dosages of 10 to 45 mg compared with diazepam and placebo. A secondary goal was to test for possible discontinuation symptoms after abrupt discontinuation of therapy. After a 1-week washout period, patients were treated for 8 weeks and then abruptly shifted under single-blind conditions for 2 weeks on placebo. The highest attrition rate occurred with patients on gepirone (58%) and the lowest on diazepam (34%). Medication intake for week 4 was 19.5 +/- 12.5 mg/day diazepam and 19.0 +/- 11.5 mg/day gepirone and was similar at week 8. The major adverse events were light-headedness, nausea, and insomnia for gepirone and drowsiness and fatigue for diazepam. Clinical improvement data showed gepirone's anxiolytic response to be delayed, being significant from placebo beginning at week 6, whereas diazepam caused significantly more relief than placebo from week 1 onward. Taper results showed that only diazepam, but not gepirone, caused a temporary worsening of anxiety symptoms or rebound. (J Clin Psychopharmacol 1997;17:272-277)
(Rickels, Schweizer, DeMartinis, Mandos, Mercer) Mood and Anxiety Disorder Section, Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania; (Mandos) Philadelphia College of Pharmacy and Science, Philadelphia, Pennsylvania.
Received October 21, 1996; accepted after revision February 21, 1997.
Address requests for reprints to: Karl Rickels, MD, University of Pennsylvania, Department of Psychiatry, University Science Center, 3600 Market Street, Suite 803, Philadelphia, PA 19104-2649.