7a-methyl-19-nortestosterone maintains sexual behavior and mood in hypogonadal men
Anderson,Richard A.; Martin,C.W.; Kung,Annie W.C.; Everington,D.; Pun,T.C.; Tan,K.C.B.; Bancroft,John; Sundaram,Kalyan; Moo-Young,Alfred J.; Baird,David T.
Journal of Clinical Endocrinology and Metabolism 84(10): 3556-3562
Publication date: 1999
The synthetic steroid 7-methyl-19-nortestosterone (MENT) isa potent androgen that is resistant to 5-reductase. It thushas decreased activity at the prostate and may have advantagesover testosterone-based regimens in long term treatment or aspart of a male contraceptive. Administration to eugonadal menresults in suppression of gonadotropins, but its ability tosupport androgen-dependent behavior has not been investigated.For sustained release administration, MENT acetate was used,because its diffusion characteristics were more suitable foruse in implants. However, upon release the acetate is rapidlyhydrolyzed, and MENT is the biologically active moiety in circulation.We studied the effects of MENT on sexual interest and activity,spontaneous erection, and mood states in comparison with testosteroneenanthate (TE) in 20 Caucasian and Chinese hypogonadal men recruitedin Edinburgh and Hong Kong (n = 10 in each center). Outcomeswere measured using a combination of daily diaries, semistructuredinterviews, and questionnaires. Nocturnal penile tumescence(NPT) was also recorded in the Edinburgh group. After withdrawalof androgen replacement treatment (wash-out phase) for a minimumof 6 weeks, subjects were randomized to two groups in a cross-overdesign. Drug treatment regimens were of 6-week duration and consistedof two implants, each containing 115 mg MENT acetate, insertedsc into the upper arm and removed after 6 weeks and two injectionsof TE (200 mg, im) 3 weeks apart. MENT treatment resulted in stableplasma MENT concentrations of 1.4 ± 0.1 nmol/L after3 weeks and 1.3 ± 0.1 nmol/L after 6 weeks (mean ± SEM;all men). Nadir testosterone concentrations were 3.6 ±0.6 nmol/L at the end of the wash-out phase and 9.4 ± 0.6nmol/L 3 weeks after each injection. There were no differencesin hormone concentrations between centers. There were no adverse toxicologicaleffects.