The FDA has approved a 0.75% ophthalmic solution of the alpha-adrenergic antagonist phentolamine (Ryzumvi – Viatris) for treatment of mydriasis produced by adrenergic agonists such as phenylephrine or parasympatholytic agents such as tropicamide in patients ≥3 years old. Ryzumvi is the first drug to be approved in the US for reversal of pharmacologically induced mydriasis.

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.

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.

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.

Clevidipine (Cleviprex - The Medicines Company), a dihydropyridine calcium channel blocker (CCB), has been approved by the FDA for intravenous (IV) use in lowering high blood pressure. It is the second IV CCB to be marketed in the US; nicardipine has been available in an IV formulation (Cardene IV) for more than 10 years. Like IV nicardipine, clevidipine will probably be used mainly for urgent treatment of hypertension in intensive care units, operating rooms and emergency departments.

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.

Many fermented foods contain tyramine as a byproduct formed by the bacterial breakdown of the amino acid tyrosine; it can also be formed by para-hydroxylation of phenylethylamine or dehydroxylation of DOPA and dopamine. Tyramine and some other amines found in food can cause hypertensive reactions in patients taking monoamine oxidase (MAO)inhibitors.

Ever-increasing specialization has made it difficult for many physicians to keep up with therapeutic standards in intensive-care units (ICUs). This issue of Treatment Guidelines offers current recommendations for use of cardiovascular drugs in the ICU for treatment of hypertensive emergencies; shock, cardiac arrest or decompensated heart failure; and ventricular arrhythmias.