Effects of Brofaremine (CGP 11 305A), a Short-acting, Reversible, and Selective Inhibitor of MAO-A on Sleep, Nocturnal Penile Tumescence and Nocturnal Hormonal Secretion in Three Healthy Volunteers

The effects of brofaremine (CGP 11 305A), a short-acting, reversible and selective inhibitor of MAO-A, on sleep, nocturnal penile tumescence (NPT) and hormonal secretion during the night were studied during a long-term trial. Three healthy males underwent sleep-EEG and NPT recordings during consecutive nights (1) under placebo, (2) under stepwise increasing dosages of brofaremine and (3) under placebo after withdrawal. Hormone profiles were sampled during selected nights to analyze the plasma concentration of cortisol, HGH, prolactin, testosterone, LH and FSH. REM sleep was suppressed markedly under 150 mg brofaremine, while stages 1 and 2 increased. In comparison to the effect of irreversible MAOIs the REM suppression was shorter and did not persist after withdrawal. A decrease of the plasma concentration of the drug coincided with a return of sleep variables to baseline values. A REM rebound occurred after withdrawal of brofaremine. REM sleep and NPT showed a dissociation; NPT variables did not follow the decrease of REM sleep. The effects of REM parameters are correlated with the dosage and the plasma concentration of the substance. Intraindividually, a decrease in secretion of HGH was observed throughout the trial. No marked changes were found in the other endocrinological variables.