Effect of methadone on the male reproductive system.

Daily injections (s.c.) of methadone HCL (5, 10 or 20 mg/kg) for 5 or 10 days caused significant regression (p less than or equal to 0.05) in the weights of sex accessory organs and testes in mature mice. Similar treatment regimens led to significant elevations in the levels of cyclic adenosine monophosphate (cAMP) in the prostate gland (P less than or equal to 0.05). Daily injuctions of morphine sulfate (10, 20 or 40 mg/kg) likewise caused significant increases in cAMP levels in the prostate gland (P less than or equal to 0.05). When either of these drugs were incubated in vitro with prostate glands obtained from normal mice, the cAMP levels were also observed to be elevated (P less than or equal to 0.05). The results reveal that so-called analgesic drugs can exert deleterious actions upon male reproductive tissues in the mouse.