But, keep in mind that ED might signal an underlying medical problem, like high blood pressure, heart disease, diabetes, low testosterone, or sleep apnea. These include itraconazole Sporanox, Tolsura , ketoconazole Extina, Ketozole, others and ritonavir Norvir. Vardenafil usually works for 4 to 5 hours. Some examples of nitrates are nitroglycerin Nitro-Dur, Nitrostat, others , isosorbide mononitrate Monoket and isosorbide dinitrate Bidil. This boosts blood flow and helps you get an erection from sexual activity. These medicines are called PDE5 inhibitors.Can You Buy Viagra Over the Counter? A straightforward answer: Yes! Since , the ED medication Viagra has been available over the counter at many pharmacies, under the brand name Viagra Connect – only in the licensed strength of 50mg. Clinically proven to treat men with erectile dysfunction (ED) Ongoing commitment to product quality and safety monitoring Learn More IF YOU CHOOSE BRAND-NAME VIAGRA, MAKE SURE YOU GET THE BRAND NAME Your prescription may have been filled with a generic version instead of brand-name VIAGRA. It also includes natural or over-the-counter ED treatments, such as l-arginine and yohimbine. Taking Viagra with other ED medications increases your risk of certain side effects, such as low.