Sedative effects and prolactin response to single oral doses of melperone

The pharmacokinetics of melperone and the relationship between plasma concentration and the effect on arousal and prolactin secretion after single oral doses (10, 25, 50 and 100 mg) was studied in normal subjects. Dose-dependent kinetics were indicated by the fact that higher plasma concentrations than expected were demonstrated after the 100-mg dose. Melperone decreased arousal and increased prolactin secretion in a dose-dependent manner. The level of arousal was correlated to melperone plasma concentration over the entire dose range. Prolactin secretion was also correlated to melperone plasma concentration, provided the relationship was studied separately for the individual melperone doses. Thus at higher doses, higher plasma concentrations are needed to elicit the same prolactin outflow. The possibility that reduced arousal reactions might contribute in the antipsychotic action of neuroleptic drugs was discussed.