Avanafil works by blocking the enzyme phosphodiesterase type 5, which results in increased blood flow to the penis, helping to achieve and maintain an erection when sexually aroused.Avana 50 mg, known generically as Avanafil, is a medication used to treat erectile dysfunction (ED) in men. It belongs to a class of drugs known as phosphodiesterase type 5 (PDE5) inhibitors, which also includes sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra).