FDA Approves New ED Remedy
FDA on April 27 approved the phosphodiesterase type 5 inhibitor avanafil for the treatment of erectile dysfunction.
The newest drug of four in this class will be sold as Stendra by Vivus Inc., which licensed the product from Mitsubishi Tanabe Pharma Corporation of Japan. A U.S. launch date for avanafil has not yet been announced.
The labeling (PDF) for avanafil recommends taking the drug with or without food 30 minutes before sexual activity. No more than one dose should be taken per day.
The recommended starting dose of avanafil is 100 mg, but the amount may be doubled or halved on the basis of individual effectiveness or tolerability, according to the labeling. The lowest effective dose should be used.
Men whose cardiovascular condition makes sexual activity inadvisable should not take avanafil.
Like other drugs in its class, avanafil is contraindicated in men who require regular or intermittent treatment with nitrates. If a nitrate must be given on an emergency basis to a patient who has taken avanafil, at least 12 hours should lapse before the nitrate is administered, and the patient must be under close medical supervision that includes hemodynamic monitoring.
Avanafil should not be taken concomitantly with strong inhibitors of cytochrome P-450 (CYP) isoenzyme 3A4. The maximum recommended daily dosage of avanafil when used with moderate CYP 3A4 inhibitors is 50 mg.
Concomitant use of avanafil and alpha-blockers, other antihypertensive drugs, or more than three alcoholic drinks may cause symptomatic hypotension. Patients treated with an alpha-blocker who are hemodynamically stable should initiate avanafil therapy at the lowest recommended dose, 50 mg.
Avanafil oral tablets will be available in 50-, 100-, and 200-mg strengths in bottles of 30 or 100. The product should be stored at controlled room temperature.
FDA is requiring Vivus to conduct two postmarketing clinical trials to address concerns about potential adverse events associated with the use of avanafil. One clinical trial will study the effects of avanafil on spermatogenesis and must be completed by November 2013. The second clinical trial will examine the drug's effects on vision and must be completed by February 2013.