Relationship between early side effects and therapeutic effects of clomipramine therapy in obsessive-compulsive...

Early adverse effects of a drug may be a manifestation of individual differences in drug metabolism or of different pathologic processes. These differences may influence therapeutic responsiveness. Using data from Ciba-Geigy's multicenter 10-week clinical trial, we studied the relationship between early side effects and subsequent therapeutic response to clomipramine (CMI) in obsessive-compulsive disorder. We used tabular analyses and multiple regression to evaluate associations between early complaints and change in score on the Yale-Brown Obsessive-Compulsive Scale. We also evaluated whether early complaints were drug related (i.e., true side effects). It appeared that dry mouth, constipation, dizziness, insomnia, male impotence, nervousness, palpitation, and tremor reported during the first 4 weeks were predictive of good response to CMI. Myoclonus and tinnitus appeared weakly associated with treatment success. Most of these complaints were reported more by the CMI group than the placebo group, and more during CMI treatment than before. The more common complaints may reflect an individual's ability to metabolize CMI appropriately so that adequate therapeutic blood levels are attained. The less common complaints may reflect a sensitivity to CMI's serotonergic actions.