Buprenorphine effects on plasma luteinizing hormone and prolactin in male heroin addicts.

Buprenorphine, a mixed opiate agonist-antagonist, suppressed plasma luteinizing hormone (LH) and increased prolactin levels after 12 consecutive days of ascending dose administration (0.5-8 mg/day s.c.) in comparison to drug-free control conditions. During a subsequent 10-day period of buprenorphine maintenance at a dose of a 8 mg s.c., LH levels remained suppressed and prolactin levels continued to be elevated. Tolerance to buprenorphine effects on LH and prolactin levels did not occur during chronic drug administration. Buprenorphine-induced changes in plasma LH and prolactin after chronic administration to human males were smaller than those observed with less potent opiate agonist drugs. Effects of buprenorphine on LH and prolactin levels are more consistent with the actions of opiate agonists rather than opiate antagonists.