Pharmacokinetic characteristics, efficacy, and safety of buccal testosterone in hypogonadal males: a pilot study

The endocrine pharmacology of testosterone therapy in men

The review starts off by outlining the history of the discovery of the male sex hormone testosterone and the historical background to the various, often dubious, approaches to the treatment of age-related endocrine disorders in older men. A discussion of congenital androgen deficiency in young men is followed by methods of diagnosing hypogonadism in older men. Among therapeutic options, the alternatives to direct testosterone replacement are discussed, although none of them have proved to be particularly successful in clinical practice. For testosterone replacement itself, various routes of administration and pharmaceutical formulations are now available, facilitating good monitoring and individualized therapy.

Testosterone replacement therapy in male hypogonadism

In human males 6-7 mg of testosterone are secreted by the testes in a circadian rhythm with a nocturnal rise in testosterone followed by a decline during the day. Testosterone is necessary to induce and maintain secondary sexual characteristics, lean muscle mass, bone density and for normal sexual behaviour and cognitive function in men. Replacement therapy has been shown to be beneficial in men with overt hypogonadism. Natural testosterone should be used and not modified molecules. Testosterone is currently available in oral, intramuscular, subcutaneous and transdermal preparations. Recent advances in testosterone replacement therapy include testosterone gels which provide flexibility in dosing and minimal skin irritation resulting in good compliance, and the development of longer acting intramuscular preparations which result in more stable testosterone levels with longer injection intervals. All patients receiving testosterone should be carefully monitored for changes in hematocrit, liver function, lipid parameters and prostate specific antigen (PSA).This article reviews the current experience with the use of various forms of testosterone for the treatment of male hypogonadism.