Effect of acute intravenous clomipramine and antiobsessional response to proserotonergic drugs: Is gender a predictive variable?

Background: Previous studies on serotonergic responsivity in obsessive-compulsive disorder (OCD) showed about 50% of patients experiencing an acute worsening of OC symptoms when administered meta-chlorophenylpiperazine or IV clomipramine. The aim of this study was to determine what variables influence the response to acute IV clomipramine. Could this response be predictive of the response to chronic treatment with two serotonergic drugs with differing selectivity profiles: clomipramine and fluvoxamine? Methods: Fifty OC patients were consecutively recruited. All underwent a challenge with 25 mg IV clomipramine and placebo and were administered 10-week oral clomipramine or fluvoxamine according to a double-blind design. The efficiency of the antiobsessional treatment was evaluated by Yale-Brown Obsessive-Compulsive Scale and Clinical Global Impression scale scores. Results: Obsessions worsened in 42% patients as rated by change values in 100-mm visual analogue scale scores for the clomipramine vs. placebo infusion. There was a significant difference in gender distribution between "worsened" and "unchanged" patients, since female subjects were more frequently "unchanged." Thirty-one patients completed the 10-week treatment. According to both qualitative and quantitative evaluations, female subjects showed a better antiobsessional response, and this difference was enhanced in the clomipramine-treated group. Conclusions: Results suggest a role for reproductive hormones in the pathophysiology or treatment of OC patients. Biol Psychiatry 1999;45:290-294 (C) 1999 Society of Biological Psychiatry.