The FDA today approved Stendra (avanfil), a new drug to treat erectile dysfunction. Erectile dysfunction is when a man has trouble getting or keeping an erection.
Stendra is a pill that patients take on an as-needed basis 30 minutes before sexual activity. It belongs to a class of drugs known as phosphodiesterase type 5 inhibitors (PDE5) inhibitors, which are used to help increase blood flow to the penis. The lowest possible dose of Stendra that provides benefit should be prescribed.
As is the case with other PDE5 inhibitors, Stendra should not be used by men who also take nitrates, commonly used to treat angina, since the combination can cause a sudden, unhealthy lowering of blood pressure.
Adverse effects associated with the use of PDE5 inhibitors include color vision changes, and in rare cases, a sudden loss of vision in one or both eyes. A sudden loss or decrease in hearing has also been reported in patients taking PDE5 inhibitors. Patients who experience such symptoms should stop taking PDE5 inhibitors and call a doctor immediately.
The most common side effects reported in greater than 2% of patients in the clinical studies of Stendra include headache, flushing, nasal congestion, common cold-like symptoms (nasopharyngitis), and back pain. In rare cases, patients taking Stendra and other PDE5 inhibitors may get an erection lasting four hours or longer that will not go away (priapism). If this happens, patients should seek immediate medical care.
Stendra’s safety and efficacy were established in three double-blind, placebo-controlled clinical studies. A total of 1,267 patients were randomly assigned to take Stendra for up to 12 weeks at doses of 50 mg, 100 mg or 200 mg, or a placebo as needed about 30 minutes before sexual activity.
At the start of the studies and every four weeks thereafter, patients completed questionnaires to evaluate erectile function, vaginal penetration and successful intercourse. Results showed patients taking Stendra experienced statistically significant improvement in all three endpoints for all three doses of Stendra studied.
To further evaluate Stendra’s safety, a subset of patients from two of the studies was enrolled in another trial to receive up to an additional 40 weeks of treatment. Patients were initially given Stendra at the 100 mg dose, but could have their dose increased to 200 mg or decreased to 50 mg based on their individual response to treatment. Results showed that the side effects commonly reported in patients using Stendra did not worsen over time.
Stendra is marketed by Mountain View, Calif.-based VIVUS Inc.