Stendra (Avanafil): A new oral phosphodiesterase-5 inhibitor indicated for the treatment of ED

An estimated 30 million men in the United States are affected by erectile dysfunction (ED). On April 27, 2012, FDA approved the oral phosphodiesterase-5 (PDE-5) inhibitor, avanafil (Stendra, Vivus), for the treatment of ED.

Efficacy. Avanafil was evaluated in 3 randomized, double-blind, placebo-controlled, parallel group trials of up to 3 months in duration. A total of 1,267 men were randomly assigned to take avanafil 50 mg, 100 mg, 200 mg, or a placebo as needed about 30 minutes before sexual activity. The erectile function domain of the International Index of Erectile Function (IIEF) and Questions 2 and 3 from Sexual Encounter Profile (SEP) were used as primary outcome measures. Trial results showed men taking avanafil at all 3 doses experienced statistically significant improvement in all 3 end points studied.

Safety. The most common adverse reactions (greater than or equal to 2%) observed in subjects during the 3 placebo-controlled clinical trials of avanafil included headache, flushing, nasal congestion, nasopharyngitis, and back pain. Patients receiving avanafil for an additional 40 weeks during a long-term safety study did not experience worsening of adverse effects over time. The use of avanafil along with antihypertensive agents, particularly alpha-blockers, or substantial amounts of alcohol (greater than 3 units) may lead to hypotension.

Dosing. The recommended dose of avanafil for most patients is 100 mg taken with or without food approximately 30 minutes before sexual activity on an as-needed basis, but no more than once daily. The dose of avanafil may be increased to 200 mg or decreased to 50 mg based on efficacy and/or tolerability, with the preferred dose being the lowest providing benefit. No dosage adjustment in mild-to-moderate renal dysfunction is required.

Avanafil should not be used in patients taking a nitrate or a strong CYP-3A4 inhibitor (eg, ketoconazole, ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, telithromycin), and no more than 50 mg in a 24-hour period should be used in patients concomitantly taking a moderate CYP3A4 inhibitor (eg, erythromycin, amprenavir, aprepitant, diltiazem, fluconazole, fosamprenavir, verapamil) or a stable dose of an alpha-blocker.

Avanafil should not be used when sexual activity is inadvisable because of cardiovascular or other reasons.