Pharmacodynamic comparison of the acute effects of nomifensine, amphetamine and placebo in healthy volunteers.

In a double blind cross over trial the effects of single doses of 100 mg nomifensine, 15 mg racemic amphetamine and placebo were compared in 9 healthy volunteers. Assessments of choice reaction behavior, simple reaction time, critical flicker fusion and attention on continuous calculations were performed together with a series of self rating scales, a side-effect list and vital signs before and 90 min., 180 min. and 360 min. after each administration. While the only significant nomifensine effect was an increase of correct solutions in the continuous calculation task, amphetamine differed from nomifensine and placebor in a number of subjective variables which describe emotional changes typical for drug stimulation. Subjects also expressed the will to have amphetamine prescribed for fatigue and loss of drive, whereas preferences for nomifensine were virtually the same as for placebo. Under amphetamine heart rate and blood pressure were increased and side-effects were frequent. It is concluded that nomifensine showed none of those subjectively pleasant amphetamine effects which are responsible for the reinforcement function leading to amphetamine dependence.