Erectile Dysfunction Hormonal Therapy

Referral to endocrinology is recommended for patients with thyroid, adrenal, pituitary or hypothalamic dysfunction. The urologist should be aware that aging men with ED may show a variety of symptoms when hypogonadism coexists: low libido, depression, decreased intellectual abilities, decreased lean body mass, decreased bone mineral density, decreased skin turgor, changes in body hair distribution, changes in sleep patterns, and increased visceral fat. This discussion is limited to treatment of hypogonadism and hyperprolactinemia as they relate to ED.

In the patient with documented hypogonadism and ED, it is reasonable to initiate androgen therapy. Parenteral depo-preparations of testosterone such as testosterone cypionate and enanthate are the cheapest form of androgen supplementation and are effective in restoring serum levels of testosterone to normal. They are administered through deep intramuscular injection; resulting in supraphysiologic levels of testosterone for 72 h with gradual steady decline over 2-3 weeks. Enanthate and cypionate are generally administered every 2-4 weeks at dosages of 200-400 mg. Testosterone propionate has a shorter half-life requiring dosing every other day. Transcutaneous dosing more closely simulates normal circadian levels of testosterone if patients apply the patch in the morning.

There are currently 3 FDA-approved preparations available in the United States: Testoderm/Testoderm TTS (Alza Pharmaceuticals), Androderm (GlaxoSmithKline), and AndroGel (Unimed Pharmaceuticals, Inc). Testoderm comes in 2 sizes, delivering 4 mg/d or 6 mg/d. Physiologic blood levels can be achieved in 65% of patients who apply the system to the scrotum. Testoderm TTS may be applied daily as a 5-mg patch to the arm, back, or upper buttocks, avoiding the inconveniences of scrotal therapy. Androderm comes as a patch that delivers 2.5 mg or 5 mg. The most common adverse reactions to both Testoderm TTS and Androderm are itching, chronic skin irritation, and allergic contact dermatitis. Patients should alternate sites of application and avoid sun-exposed sites, and they may be helped by local application of cortisone cream to irritated skin. Androgel 1% is a cream designed to deliver 50 mg of testosterone, applied once daily in the morning to clean, dry skin over the shoulders, upper arms, or abdomen. It is supplied in packets of 25 mg and 50 mg. The most common adverse reaction is also skin-site irritation. The oral forms available in the United States are 17α-methyl testosterone preparations. When taken orally, these preparations are largely rendered metabolically inactive during the "first pass" circulation through the liver. These preparations are toxic to the liver and can lead to hepatitis, cholestatic jaundice, hepatomas, hemorrhagic liver cysts, and hepatocarcinoma (_{Bagatell and Bremner, 1996}). Testosterone undecenoate is an oral testosterone ester relatively free of liver toxicity but is not available in the United States.