Pulse loading versus gradual dosing of intravenous clomipramine in obsessive-compulsive disorder

Objective: We compared gradually increased to pulse loaded doses of open-label, intravenous clomipramine (CMI) in patients with obsessive- compulsive disorder (OCD). Method: We treated adult outpatients with DSM- III-R OCD, who had no prior exposure to effective treatments. Pulse loading patients received 150 mg on day 1; 150 mg or 200 mg on day 2. Gradual dosing patients received 25 mg per day increased to 200 mg per day over 2 weeks and then continued for a mean of 43 days (n=40). After i.v. dosing, all patients received oral CMI; the total treatment period was 6 months. Results: Pulse loading completers (n=7) had a rapid, dramatic response (mean Y-BOCS score decrease of 32% five days after pulse-loading). At this point (day 7), completers in the gradual intravenous group (n=20) exhibited no mean change in Y-BOCS score. The pulse loading group reached both a 25% or greater and a 50% or greater decrease in Y-BOCS score statistically and clinically significantly faster than the gradual group. Conclusions: Pulse-loaded intravenous CMI for the treatment of OCD deserves further study.