THE EFFECTS OF REMOXIPRIDE AND CHLORPROMAZINE ON EYE-MOVEMENTS AND PSYCHOMOTOR PERFORMANCE IN HEALTHY-VOLUNTEERS

Fifteen healthy male volunteers received single doses of 100 mg immedi ate release remoxipride (IR), 150 mg controlled release remoxipride (C R), 50 mg chlorpromazine (CPZ), 2 mg lorazepam (LZ), and placebo in a randomised, five-period cross-over study. Both saccadic (SEM) and smoo th pursuit eye movements (SPEM) as well as a battery of psychomotor pe rformance tests were assessed at 1.5-h intervals over 9 h following dr ug administration. The areas under the response-time curves and the ma ximum effect during the study period were analysed by analysis of vari ance. The most consistent impairments were produced by LZ. The neurole ptics caused impairments to SEM, and tended to impair critical flicker fusion, continuous attention and both paced and unpaced versions of t he digit-symbol substitution test as well as subjective measures of se dation. Only LZ impaired SPEM. Neither paced nor unpaced psychomotor t ests distinguished between neuroleptics and benzodiazepines. The low t herapeutic doses of IR and CR produced similar impairments to a sub-th erapeutic dose of CPZ. Selectivity of pharmacological action does not appear to predict selectivity of effect on psychomotor function.