Testosterone replacement therapy in male late onset hypogonadism: available pharmacological strategies

During the last few years, the general aging of the population and the growing knowledge about male hormonal changes in older age have lead the scientific community to focus on the clinical aspects of secondary hypogonadism in aging males. This syndrome is well defined by the term late-onset hypogonadism (LOH). Although the pathophysiology and the diagnostic aspects have been studied and defined and various preparations are available, the debate on androgen supplementation therapy is still ongoing. As the spectrum of effects of endogenous testosterone is essentially based on its metabolism to dihydrotestosterone and estradiol, testosterone is the treatment of choice for male hypogonadism. The aim of the therapy is to establish a physiological concentration of serum testosterone in order to correct the androgen deficiency, relieve its symptoms and prevent long-term sequelae. All of the available products, despite their varying pharmacodynamic and pharmacokinetic profiles, are able to reach this goal. Here we examine the indications for therapy, the characteristics of the different routes of administration and how to monitor therapy in order to make the treatment safe and effective.