A phase II, randomized crossover study published in BJU International has demonstrated the safety and efficacy of avanafil for treating men with erectile dysfunction (ED).

83 men in eight US research centres were included in the study, 80 of whom received all treatments (placebo, 50 mg sildenafil and 50, 100 or 200 mg avanafil). Men received a single oral dose of the agents in a random sequence at weekly clinic visits; dosing of avanafil was increased sequentially, after the safety of the previous dose had been confirmed. RigiScan® monitors (Dacomed Corp., Minneapolis, MN, USA)—an objective and validated apparatus for determining erectile rigidity—were used to evaluate baseline and treatment-induced erectile responses. Measurements taken at both the base and tip of the penis included time to ≥60% rigidity, duration of ≥60% rigidity, maximum rigidity, tumescence activity units and rigidity assessments units. Men also completed a five-point questionnaire to self-assess their response as 'none', 'some enlargement', 'full enlargement', 'erection sufficient for full intercourse' or 'rigid erection'.

Avanafil was associated with few adverse effects, with facial flushing the most commonly reported. Erectile responses to avanafil and sildenafil were similar, but, notably, duration to ≥60% rigidity occurred in the early phase after treatment with avanafil (20–40 min), compared with the mid or late phases (60–80 min and 100–120 min) for sildenafil. In the context of an on-demand treatment, this characteristic makes avanafil an attractive treatment option for men with ED.