A Potent Aphrodisiac Drug Combination: Naloxone and N-n-Propyl-Norapomorphine

Abstract

Publisher Summary This chapter discusses a potent aphrodisiac drug combination which is naloxone and N-n-propyl-norapomorphine (NPA). Studies have shown that low doses of dopamine (DA) receptor stimulants, such as apomorphine, N-n-propyl-norapomorphine, amphetamine, L-Dopa, and amantadine, injected to adult male rats produce repeated episodes of penile erection (PE). NPA is by far the most potent compound to induce such a response, the minimum active dose being in the order of tenths of micrograms per kilogram. Moreover, apomorphine and NPA produce a bell-shaped dose-response curve, in that the effect is proportional to the dose up to the maximum active dose, then higher doses are progressively less effective until the stimulant effect ceases, and finally, even the normal occurrence of PE is suppressed. The sexual stimulant effect of apomorphine and NPA seems to be because of the stimulation of central DA receptors. They are prevented by the centrally acting neuroleptics but not by domperidone which fails to cross the blood–brain barrier. Experimental evidence suggests that endogenous peptides may play an antagonistic role against DA in the control of sexual behavior.