Avanafil (Stendra, Vivus), a new drug to treat erectile dysfunction (ED), was approved today by the US Food and Drug Administration (FDA).
It becomes the fifth FDA-approved branded oral drug for ED. The others are tadalafil (Cialis, Eli Lily), vardenafil (Levitra, Staxyn, Bayer Healthcare Pharmaceuticals), and sildenafil (Viagra, Pfizer).
Like the others, avanafil belongs to the drug class called phosphodiesterase type 5 (PDE5) inhibitors, which increase blood flow to the penis. As a PDE5 inhibitor, avanafil should not be prescribed for men who also take nitrates, commonly used to treat angina, because the drug combination can cause blood pressure to plummet, the FDA said in an announcement today. In addition, the agency cautions that PDE5 inhibitors may on rare occasions trigger color vision changes, a sudden loss of vision or hearing, and erections lasting more 4 hours or more.
Avanafil is to be taken on as-needed basis 30 minutes before sexual activity. Clinicians should prescribe the lowest dose that works for an individual patient.
The FDA said that 3 clinical trials involving 1267 patients established the safety and effectiveness of the new drug. They were randomly assigned to take various doses of avanafil or a placebo for up to 12 weeks. Patients receiving avanafil reported significant gains in erectile function, vaginal penetration, and successful intercourse.
The most common adverse events, reported in more than 2% of patients in the clinical trial, were headache, flushing in the face and other areas, nasal congestion, symptoms of nasopharyngitis, and back pain.
More information about the FDA's approval of avanafil is on the agency’s Web site.