Effects of acetylmethadol on plasma testosterone

Plasma testosterone levels were measured in a group of 13 men maintained on acetylmethadol for treatment of opiate dependence. Prior to acetylmethadol administration, plasma testosterone levels were within normal adult ranges. Four hours following ingestion of acetylmethadol, plasma testosterone levels were significantly depressed and continued to fall 7-9 hr after drug administration. Plasma testosterone levels remained low 24-25 hr after the drug was taken, but, 48 hr following drug, plasma testosterone levels rose to values approximating those prior to drug. Depression of plasma testosterone levels following acetylmethadol ingestion was not only statistically but also biologically significant, since in many patients the levels were below the normal range for adult males.