A dose-finding and discontinuation study of clomipramine in panic disorder

Eighty-one panic disorder patients with or without agoraphobia were treated with flexible doses of clomipramine under single-blind conditions. Fifty-seven (70.3%) reached operational criteria for full remission in 18.2 +/- 6.5 weeks, with a mean dose of 89.1 +/- 8.2 mg/day. Fifty-four (81%) of them received a continuous post-remission maintenance treatment at full doses of clomipramine for 4-6 months. No patient relapsed during the clomipramine maintenance phase. Their medication was then tappered and discontinued with placebo substitution under double-blind conditions. Fifty-one (63%) patients were followed-up until relapse or recurrence for up to 3 years, with periodic assessments. Three different outcome groups were identified: the first (n = 19, 19; 37.2%) experienced an early/immediate relapse (5.2 +/- 4.9 weeks after drug discontinuation); the second group (n = 22, 22; 43.1%) experienced recurrence after 42.9 +/- 35 weeks following discontinuation; and the third group (n = 10, 10; 19.6%) remained assymptomatic and functionally well throughout the follow-up. Predictors of early relapse were: (1) higher baseline score in the Beck Depression Inventory; (2) higher global score on the phobic avoidance scale after the full remission criteria; and (3) the need for higher clomipramine doses to reach full remission. The need for long-term or intermittent maintenance for most patients is emphasized.