THE EFFECTS OF SULPIRIDE ON PSYCHOMOTOR PERFORMANCE AND SUBJECTIVE TOLERANCE

In many European countries, the substituted benzamide sulpiride is use d with antidepressant indication in the dosage range of 150-300 mg on an outpatient population. This raises the concern of possible impairme nts of psychomotor performance in this dosage range. To address this q uestion, the psychometric effects of 300 mg of sulpiride in comparison with placebo in 12 healthy volunteers was evaluated in this study. In a randomised, double-blind, two-way, within-subjects (cross-over) des ign, visuomotor performance was assessed using time estimation, critic al flicker fusion, and choice reaction time tasks at baseline and 4 h after oral administration of either 300 mg of sulpiride or placebo. In addition, self-ratings on subjective well-being were obtained. Result s were evaluated using analysis of covariance (ANCOVA) with baseline l evels as covariates. In healthy subjects, 300 mg of sulpiride caused n o alteration in time estimation and choice reaction movement time, whe reas critical Bicker fusion frequency was lower and choice-reaction de cision time were prolonged under medication. Self-rating scales showed no significant differences between sulpiride and placebo. Subjects we re not able to tell whether they received placebo or sulpiride. This s tudy indicates that sulpiride is subjectively well tolerated at a dosa ge of 300 mg. However, using psychometric methods, effects are demonst rable that can be interpreted as a reduction of excitatory arousal wit hout causing the subjective experience of sedation. These results call for caution when prescribing the drug to outpatients. (C) 1997 Elsevi er Science Ireland Ltd.