General Information

Stendra (avanafil) is a phosphodiesterase 5 (PDE5) inhibitor. 

Stendra is specifically indicated for the treatment of erectile dysfunction.

Stendra is supplied as a tablet designed for oral administration. The recommended initial dose of Stendra is 100 mg taken approximately 30 minutes before sexual activity with or without food. The dose may be increased to 200 mg or decreased to 50 mg. Use the lowest dose that provides benefit on an as needed basis no more than once per day.

Mechanism of Action

Stendra (avanafil) is a phosphodiesterase 5 (PDE5) inhibitor. The physiologic mechanism of erection of the penis involves release of nitric oxide (NO) in the corpus cavernosum during sexual stimulation. NO then activates the enzyme guanylate cyclase, which results in increased levels of cGMP, producing smooth muscle relaxation in the corpus cavernosum and allowing inflow of blood. Avanafil has no direct relaxant effect on isolated human corpus cavernosum, but enhances the effect of NO by inhibiting PDE5, which is responsible for degradation of cGMP in the corpus cavernosum. Because sexual stimulation is required to initiate the local release of nitric oxide, the inhibition of PDE5 has no effect in the absence of sexual stimulation.

Side Effects

Adverse effects associated with the use of Stendra may include, but are not limited to, the following:

• headache
• flushing
• nasal congestion
• nasopharyngitis
• back pain

Clinical Trial Results

The FDA approval of Stendra was based on the results of 3 randomized, double-blind, placebo-controlled, parallel group trials. The trials enrolled subjects who self administered Stendra 50 mg, 100 mg, or 200 mg 30 minutes prior to initiating sexual activity. Subjects could request an adjustment in treatment dosage based on individual response. The 3 primary outcome measures were the erectile function domain of the International Index of Erectile Function (IIEF) and Questions 2 and 3 from Sexual Encounter Profile (SEP). Stendra demonstrated statistically significant improvement from baseline in all three dose arms against the placebo. A subset of patients from 2 of these trials were enrolled into an open-label extension trial to evaluate Stendra in ED patients with type 1 or type 2 diabetes mellitus in a randomized, double-blind, parallel, placebo-controlled fixed dose trial of 3 months in duration. Stendra or placebo was administered in doses of 100 mg or 200 mg. Subjects in the treatment arms demonstrated statistically significant improvement from baseline against the placebo upon evaluation based on the IIEF and SEP measures.