Comparison of long-acting testosterone undecanoate formulation versus testosterone enanthate on sexual function and mood in hypogonadal men.

OBJECTIVE To compare the effects of two treatment modalities of testosterone on sexual functioning and mood. Design Forty men were randomized to receive either parenteral testosterone enanthate (TE) or long-acting parenteral testosterone undecanoate (TU) over a period of 30 weeks. Thereafter, 20 men who had received TU and 16 men who had received TE continued with TU and completed another 65 weeks to study longer-term effects of TU. METHODS The following variables of sexual functioning were studied: sexual thoughts and fantasy, sexual interest and desire, satisfaction with sex life, number of erections and ejaculations per week, and number of spontaneous morning erections per week. Also variables related to mood were analyzed. RESULTS Improvements in these variables were significant and were of a similar magnitude in the group treated with TU and TE for 30 weeks. Improvements were maintained at the same levels over a period of another 65 weeks when all men received TU. Effects on mood were recorded for 30 weeks, but were more difficult to establish in the study population. There were significant differences in baseline values between the two groups and scores showed wide s.d. CONCLUSIONS Both TE and TU were effective in improving sexual functions in hypogonadal men. An advantage of TU over TE is its lower frequency of administration and its better tolerability and safety profile.