Intramuscular testosterone undecanoate for the treatment of male hypogonadism–review of recent data

Androgen preparations are indicated for the treatment of male hypogonadism. The re-establishment of normal testosterone (T) levels in hypogonadal men has been shown to result in improved libido, erectile quality and mood and to have positive effects on body composition and other parameters. Several treatment options exist for hypogonadal patients; the most commonly used include injectable intramuscular testosterone esters such as testosterone enanthate administered at intervals of 2–3 weeks, which often leads to temporary fluctuations in serum testosterone levels. A novel injectable testosterone ester, testosterone undecanoate (TU), is as effective and safe as the standard injectable formulation and requires only four injections per year in long-term treatment while maintaining serum T levels within the physiological range. Recent data confirm the safety and efficacy of long-term TU therapy in patients treated over a period of up to 7.5 years and show the positive impact of testosterone on the cavernosal tissues that are pathologically altered due to androgen deficiency in an animal model and in humans. Men with erectile dysfunction and low serum testosterone may benefit from testosterone administration and the combination of phosphodiesterase 5-inhibitors and testosterone may be indicated in men who do not respond sufficiently to testosterone alone.