Injections or Topical Treatments

Injections Using Papaverine and Phentolamine

Until the introduction of alprostadil, the two drugs used for injection therapy had been papaverine (Pavabid, Cerespan) and phentolamine (Regitine). Adverse reactions are usually minor but include pain, ulcers, and prolonged erections (priapism).

Testosterone Replacement Therapy

Testosterone replacement therapy may be helpful for some men, particularly those with hypogonadism. Forms of testosterone therapy include:

• Muscle injections using testosterone enanthate (Andryl, Delatestryl) or cypionate (Andro-Cyp, Depo-Testosterone, Virion). This has been the standard administration.
• Skin patch (Testoderm, Testoderm TTS, Androderm). Depending on the brand, patches may be applied to the skin of the scrotum every 24 hours or to the abdomen, back, thighs, or upper arm. In the latter case, two patches are required every 24 hours. Testoderm and Testoderm TTS may cause less skin irritation than Androderm.
• Skin gel (Androgel, Testim). At this time, the gel is applied only to the same parts of the body as the patch. A gel applied to the penile skin is being investigated for men with hypogonadism and erectile dysfunction. Pregnant women must avoid contact with the gel because theoretically the testosterone could harm the fetus.

Oral forms of testosterone are not recommended because of the risk for liver damage when taken for long periods of time.

Testosterone replacement is used or investigated in the following:

• Replacement Therapy for Hypogonadism. Testosterone replacement therapy may be effective in inducing puberty in adolescent boys with hypogonadism and may also be helpful for some adult patients with the condition. Either the skin patch or gel achieves normal testosterone levels in 67 - 90% of men. The gel is proving to be more effective than the patch at improving sexual desire and well being. It may also be more effective in boosting energy and mood and increasing muscle mass and weight in men with testosterone deficiencies.
• Replacement for Older Men with Androgen Deficiencies. Some experts believe testosterone replacement therapy may be helpful for older men whose androgen (male hormone) levels are deficient.
• Testosterone in Men with Normal Levels. Testosterone therapy is not recommended for men with testosterone levels that are normal for their age group. One 2003 study did report that short-term (one-month) use of the patch in men with low-normal testosterone levels improved their response to sildenafil (Viagra).