This allows the smooth muscles in the penis to relax and fill with blood. Most erectile dysfunction medications belong to the drug class known as PDE5 inhibitors , which help relax the muscles and increase blood flow to allow for a full erection. According to the FDA, generic medications contain the same active ingredients as brand names, meaning there’s no difference in effectiveness or safety. It may be difficult to remain firm despite wanting to have sex. Insurance can help you save even more on consultations and medications. Your primary care doctor should always know what medications you’re taking, including ED pills prescribed by another provider.Tadalafil (Cialis). This medication is taken with or without food an hour before sex. It works for up to 36 hours. You can take it in a small dose daily or in a larger . We have good news for you: generic Cialis, used to treat erectile dysfunction (ED)and enlarged prostates, just hit pharmacies. Prices for the generic, .