The prostaglandin alprostadil injected into the corpus cavernosum (Caverject - Upjohn) can produce an erection in some men with erectile dysfunction (Medical Letter, 37:83, 1995). Now a pellet (microsuppository) formulation has become available for intraurethral administration of alprostadil (MUSE [Medicated Urethral System for Erection] - Vivus). It is marketed in a sterile foil pouch containing a pellet 1.4 mm in diameter and 3 or 6 mm long within the stem of a hollow applicator, which is inserted 3 cm deep into the urethra. Pressing a button pushes the pellet into the urethra.

An aqueous formulation of alprostadil (prostaglandin E 1 ; - Upjohn) has been approved by the US Food and Drug Administration (FDA) for injection into the corpus cavernosum to treat erectile dysfunction. The drug is also marketed as Prostin VR, an alcohol-containing formulation, for intravenous use in newborns with congenital heart disease to maintain the patency of the ductus arteriosus.

Self-injection of papaverine, a smooth muscle relaxant, and phentolamine (Regitine), an alpha-adrenergic blocker, directly into the corpus cavernosum has been effective for treatment of impotence in some patients, even after complete quadriplegia, radical surgery for bladder or prostate cancer, or castration (Medical Letter, 29:95, 1987). Recently, injections of prostaglandin E1, now called alprostadil (Prostin VR - Upjohn), have also been tried for this purpose. No drug is approved for this use by the US Food and Drug Administration.

Low-intensity extracorporeal shockwave therapy similar to that used to fragment kidney stones or gallstones is a new option for treatment of erectile dysfunction that is now being advertised extensively in the US. It has not been approved by the FDA for treatment of erectile dysfunction.

Sildenafil citrate (Viagra - Pfizer) is the first oral drug approved by the FDA for treatment of erectile dysfunction. Alprostadil is also marketed for this indication but must be injected into the corpus cavemosum (Caverject) or pushed into the urethra (MUSE).

Sexual complaints related to desire, arousal, orgasm and painful intercourse are common in women. Since the last Medical Letter article on this subject, some new information has become available.

The FDA has authorized over-the-counter (OTC) sale of a nonmedicated alcohol-based gel (Eroxon – Futura) for treatment of erectile dysfunction (ED) in males ≥22 years old. Eroxon is the only FDA-approved OTC and topical treatment for erectile dysfunction. It is also available in the UK and the EU.