Effects of acute intravenous clomipramine on obsessive-compulsive symptoms and response to chronic treatment.

The aim of this study was to test the hypothesis that obsessive-compulsive symptoms are temporarily worsened by acute intravenous clomipramine, suggesting that there is a basal hypersensitivity of serotonin (5-HT) receptors in obsessive-compulsive (OC) patients. We also investigated the relationship of the effects of acute (intravenous) and chronic (oral) administration of clomipramine. Twenty-eight OC patients were recruited. The first part of the study included placebo and clomipramine infusions and monitoring of OC symptoms by 100 mm Visual Analogue self-rated scales (VAS). There was significant worsening of obsessions in the whole sample during clomipramine infusion. The second part included standardized 10-week oral treatments with clomipramine and evaluation of clinical efficacy. Among the 18 patients who completed the second part of the study, oral clomipramine significantly reduced OC symptoms, but OC patients who had become worse after clomipramine infusion showed higher Y-BOCS scores.