The FDA has approved avanafil (Stendra – Vivus), an oral phosphodiesterase type-5 (PDE5) inhibitor, for treatment of erectile dysfunction. It is the fifth PDE5 inhibitor to be approved for this indication. Advertisements on Stendra’s website imply that it has a faster onset of action than other PDE5 inhibitors.

The FDA recently advised health care professionals and consumers not to use a number of dietary supplements found to contain the phosphodiesterase-5 inhibitor sildenafil (Viagra) or an analog of the drug (www.fda.gov). Although the effects of sildenafil may be noticeable (in men), the presence of other, possibly more toxic adulterants in dietary supplements may be more difficult or impossible to detect.Other drugs previously found in dietary supplements have included lovastatin (Mevacor, and others), estrogen, alprazolam (Xanax, and others), indomethacin (Indocin, and others) and warfarin...

The FDA has approved the use of nitroglycerin ointment 0.4% (Rectiv – ProStrakan/Aptalis) for treatment of moderate to severe pain associated with chronic anal fissure; the same drug is marketed as Rectogesic in Europe. Nitroglycerin ointment 2% (Nitro-Bid) is available in the US for prevention of angina.

The FDA has approved a sublingual powder formulation of nitroglycerin (GoNitro – Espero) for prevention or acute relief of an attack of angina pectoris. It is the first powder formulation of nitroglycerin to become available in the US. Most patients with angina use sublingual nitroglycerin tablets (Nitrostat, and generics). Translingual spray formulations of nitroglycerin (NitroMist, Nitrolingual Pumpspray, and generics) are also available.

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.

The FDA has approved the use of the phosphodiesterase-5 (PDE-5) inhibitor tadalafil (Cialis – Lilly) for treatment of signs and symptoms of benign prostatic hyperplasia (BPH) in men with or without erectile dysfunction. Tadalafil is approved for use under another brand name (Adcirca) for treatment of pulmonary arterial hypertension. The other PDE-5 inhibitors available in the US for treatment of erectile dysfunction (sildenafil [Viagra]; vardenafil [Levitra]) have also been reported to be effective for treatment of BPH signs and symptoms, but have not been approved for this...

The phosphodiesterase type 5 (PDE5) inhibitor tadalafil (Cialis - Lilly) is now being promoted for once daily treatment of erectile dysfunction. Tadalafil differs from sildenafil (Viagra) and vardenafil (Levitra), the other PDE5 inhibitors marketed for erectile dysfunction in the US, in having a much longer duration of action.

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.

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.