More serious side effects may include a drop in blood pressure or an erection that lasts longer than four hours. This is important for your overall health and safety, as certain medications can negatively interact with each other or cause existing conditions to worsen. Erectile dysfunction can be caused by a variety of factors , including age, cardiovascular problems, diabetes, and other conditions that affect nerve function or blood flow. Stendra avanafil : This is an as-needed medication taken 30 minutes before sex and can last up to six hours. They have the same benefits and risks as their brand-name counterparts.AdEnjoy low prices and get fast, free delivery with Prime on millions of products. Discover new arrivals & latest discounts in prime shopping online from your favorite has been visited by 1M+ users in the past monthTypes: Amazon Devices · Try Before You Buy · Limited Time Deal · Learn More. Amazon Pharmacy: Vardenafil (Generic for Levitra, Oral Tablet).us. Account Returns& Orders. Cart. Transfer your prescription for Vardenafil (Generic for Levitra, Oral .