Avanafil for Erectile Dysfunction

Objective: To review the pharmacology, pharmacokinetics, safety, and efficacy of avanafil and evaluate relevant clinical trial data. Data Sources: A MEDLINE, International Pharmaceutical Abstracts, ClinicalTrials.gov, and Google Scholar searches (1966 to July 2013) were conducted using the key words: avanafil, erectile dysfunction, and phosphodiesterase type 5 (PDE5) inhibitor. Study Selection and Data Extraction: Articles evaluating avanafil for erectile dysfunction (ED) published in English and using human subjects were selected. Five clinical trials were identified. References cited in identified articles were used for additional citations. Data Synthesis: Avanafil is a highly selective PDE5 inhibitor that is a competitive antagonist of cyclic guanosine monophosphate. Specifically, avanafil has a high ratio of inhibiting PDE5 as compared with other PDE subtypes allowing for the drug to be used for ED while minimizing adverse effects. Absorption occurs quickly following oral administration with a median Tmax of 30 to 45 minutes and a terminal elimination half-life of 5 hours. Additionally, it is predominantly metabolized by cytochrome P450 3A4. As such, avanafil should not be co-administered with strong cytochrome P450 3A4 inhibitors. Dosage adjustments are not warranted based on renal function, hepatic function, age or gender. Five clinical trials suggest that avanafil 100 and 200 mg doses are effective in improving the Sexual Encounter Profile and the Erectile Function Domain scores among men as part of the International Index of Erectile Function. A network meta-analysis comparing the PDE5 inhibitors revealed avanafil was less effective on Global Assessment Questionnaire question 1 while safety data indicated no major differences among the different PDE5 inhibitors. The most common adverse effects reported from the clinical trials associated with avanafil were headache, flushing, nasal congestion, nasopharyngitis, sinusitis, and dyspepsia. Conclusions: Avanafil is a potent PDE5 inhibitor and is an effective treatment option for ED.