Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes .This boosts blood flow and helps you get an erection from sexual activity. Vardenafil usually works for 4 to 5 hours. Oral ED medicines might not work or might be dangerous if you also take any of the following: Nitrate medicines. This, in my view, is the key issue in this appeal. Such patients must not apply any out-of-pocket expenses incurred using this Savings Offer toward any government insurance benefit out-of-pocket spending calculations, such as Medicare Part D true out-of-pocket TrOOP costs You are responsible for reporting use of this Savings Offer to any private insurer, health plan, or other third party who pays for or reimburses any part of the prescription filled using this Savings Offer, as may be required.Learn about uses, how it works, and more for Viagra (sildenafil). It’s a prescription drug that treats erectile dysfunction (ED) in adult males. VIAGRA does not protect against sexually transmitted diseases, including HIV. The most common side effects of VIAGRA: headache; flushing; upset stomach; abnormal vision, . Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes .Samples were also taken from a year-old male found dead in his car. More testing revealed the presence of desmethyl carbodenafil, which is an unapproved sildenafil analog, at a concentration of 0. Studies showed that PDE5 inhibitors might contribute to death in patients with cardiovascular disease after sexual intercourse at low concentrations 0. The contraindication to using PDE5 inhibitors in these patients was a history of cardiovascular disease in cases one and two. The fourth case was a man in his 80s complaining of dizziness and fever after having sex who then died after resting for a period.