Plasma levels of dihydrotestosterone remain in the normal range in men treated with long-acting parenteral testosterone undecanoate

Abstract

The major goal of androgen therapy is to achieve testosterone levels as close to physiological concentrations as possible. For some androgen-dependent functions, testosterone is a pro-hormone, peripherally converted to 5 alpha-dihydrotestosterone (DHT) and 17beta-oestradiol of which the levels preferably should also be within their normal physiological ranges. In this study, the resulting plasma DHT levels in 122 hypogonadal men treated with a novel testosterone treatment modality: parenteral long-acting testosterone undecanoate (Nebido), were investigated. Following the treatment, there were no abnormally high/low plasma DHT levels; levels varied between 86 and 511 ng l(-1) (normal range: 40-575 ng l(-1)). In conclusion, treatment with testosterone undecanoate generates physiological levels of DHT. Prostate safety parameters did not undergo changes.