Research Evaluating a PDE5 Inhibitor for Erectile Dysfunction

Inclusion Criteria: * Males ≥ 18 years of age; * Minimum 6 months of erectile dysfunction; * In a monogamous, heterosexual relationship for at least 3 months; * Agree to make at least 4 attempts at intercourse per month; * Provide written informed consent; * Agree not to use any other ED treatments for erectile dysfunction; * Willing and able to comply with all study requirements. Exclusion Criteria: * Allergy or hypersensitivity to PDE5 inhibitors; * History of dose-limiting AEs with a PDE5 inhibitor or discontinued use of a PDE5 inhibitor; * Concomitant use of one or more of the following medications: * Other prescription or OTC drugs known to interfere with metabolism by the CYP 3A4 enzyme; * Dose of an alpha blocker that has not been stable for at least 14 days; * Any nitrate; * ED as a consequence of advanced neurologic disease, spinal cord injury,or radical prostatectomy; * Myocardial infarction, stroke, life-threatening arrhythmia or coronary revascularization within the past 6 months; * Unstable angina, angina with sexual intercourse, or congestive heart failure \> NYHA Class II; * Poorly controlled type 1 or type 2 diabetes; * Evidence of prostate cancer or previous radical prostatectomy; * Untreated hypogonadism or total testosterone levels outside normal reference range; * Abnormal laboratory value(s) judged to be clinically significant by the investigator; * Positive urine drug screen; * History of retinitis pigmentosa, nonarteritic anterior ischemic optic neuropathy or glaucoma; * Previous participation in any other study with avanafil; * Use of any other investigational medication or device for any indication within 30 days prior to enrollment or at any time during this study; * Evidence of any clinically significant medical, psychiatric, social or other condition by history, physical examination or laboratory studies that, in the opinion of the investigator, would contraindicate the administration of study medications, affect compliance, interfere with study evaluations, limit study participation, contraindicate sexual activity or confound the interpretation of study results.