Alfuzosin hydrochloride (Uroxatral - Sanofi-Synthelabo) is now available in the US in a new formulation for once-daily treatment of benign prostatic hyperplasia (BPH). The drug has been used in Europe since 1987. Alpha₁-blockers cause relaxation of smooth muscle tone in the bladder neck, prostatic capsule and prostatic urethra, relieving symptoms of urinary obstruction.

Serious adverse interactions between drugs continue to be reported. Many of these are due to inhibition or induction of cytochrome P450 (CYP) enzymes, particularly CYP3A4. CYP3A is thought to be involved in the metabolism of more than 50 percent of currently prescribed drugs.2 CYP3A4, which is more abundantly expressed than CYP3A5, accounts for most CYP3A activity in vivo.

View the Expanded Table: Some Drugs for Altitude Illness, Jet Lag, and Motion Sickness

BiDil (NitroMed), a fixed-dose combination of isosorbide dinitrate and hydralazine, was approved by the FDA for adjunctive use in the treatment of heart failure in black patients.Both drugs are oral vasodilators that have been used together off-label for many years to treat heart failure in patients not responding to other drugs.

The ability of grapefruit juice to increase serum concentrations of drugs was first discovered during a study of the effect of ethanol on felodipine (Plendil) pharmacokinetics. Double-strength grapefruit juice used to disguise the taste of ethanol resulted in higher than expected serum concentrations of felodipine (DG Bailey et al, Clin Invest Med 1989; 12:357).

The Medical Letter reported last year that sildenafil (Viagra - Pfizer) appeared to be effective for idiopathic pulmonary arterial hypertension (PAH), but confirmation from a controlled trial was needed. Now the results of such a study are about to be published, and the drug has been approved by the FDA for this indication under the trade name Revatio.

In overactive bladder, involuntary bladder contractions due to detrusor overactivity result in urinary urgency, frequency, nocturia, and incontinence. The prevalence of the disorder increases with age. Nonpharmacologic treatment, including bladder training, urge suppression, pelvic floor muscle exercises, constipation management, modification of fluid intake, and avoidance of dietary irritants such as alcohol and caffeine, should be tried first.

The FDA has approved a lingual aerosol formulation of nitroglycerin (NitroMist – Akrimax) for acute relief of an attack or acute prophylaxis of angina pectoris. It is the second nitroglycerin lingual spray to become available in the US; Nitrolingual Pumpspray was approved in 1985. Most patients with angina use sublingual nitroglycerin tablets.

Patients who receive pretravel advice can reduce their risk for many travel-related conditions. Vaccines recommended for travelers are reviewed in a separate issue.

The FDA has approved oral and injectable formulations of the HIV-1 capsid inhibitor lenacapavir (Sunlenca – Gilead) for use with other antiretroviral drugs to treat multidrug-resistant HIV-1 infection (MDR-HIV) in heavily treatment-experienced adults whose current regimen is failing. Lenacapavir is the third drug to be approved exclusively for treatment of MDR-HIV; the intravenously administered CD4-directed antibody ibalizumab-uiyk (Trogarzo) and the orally administered HIV-1 gp120-directed attachment inhibitor fostemsavir (Rukobia) were approved earlier.