On April 27, pharmaceutical manufacturer Vivus announced the approval of its erectile dysfunction (ED) drug, Stendra (generic name avanafil) by the US Food and Drug Administration. It is the first ED medicine to be approved in over a decade, joining Viagra (sildenafil), Cialis (tadalafil), and Levitra (vardenafil) in the drug class known as phosphodiesterase type 5 inhibitors, or PDE5 inhibitors. Roughly 30 million men in the United States are affected by erectile dysfunction, and according to at least one estimate, over 50% of men will develop ED within 10 years of developing diabetes.
The body produces a chemical called cGMP during sexual stimulation, which causes the blood vessels in the penis to dilate, resulting in an erection. cGMP is broken down by an enzyme known as phosphodiesterase-5 (PDE5). PDE5 inhibitors work by blocking the action of this enzyme, causing levels of cGMP to increase and leading to a better erection.
The safety and effectiveness of Stendra was established through three double-blind, placebo-controlled trials that involved a total of 1,267 people assigned to take Stendra for as long as 12 weeks. The medicine — which may be an option for men who do not respond to Viagra, Cialis, or Levitra — will be available in 50-milligram, 100-milligram, and 200-milligram doses and should be taken 30 minutes before sexual activity at the lowest dose necessary to be effective. According to the drug maker, Stendra may work faster for some men than other medicines in its class, potentially becoming effective in as little as 15 minutes. The medicine should not be taken more than once per day.
“This approval expands the available treatment options to men experiencing erectile dysfunction, and enables patients, in consultation with their doctor, to choose the most appropriate treatment for their needs,” noted Victoria Kusiak, MD, of the FDA’s Center for Drug Evaluation and Research.
Stendra, along with all other medicines in the PDE5 inhibitor class, should not be taken by men who are taking nitrates, as the combination could cause a sudden drop in blood pressure. The most common side effects of Stendra include redness of the face and other areas, headache, nasal congestion, cold-like symptoms, and back pain. In rare cases, taking this drug can lead to an erection that lasts four or more hours. If this occurs, seek medical attention immediately. The drug can also rarely cause decreases in vision or hearing. Anyone experiencing this should stop taking PDE5 inhibitors and call a doctor immediately.