Its effects might last longer if you have mild to moderate ED. Oral medicines for ED usually work well and cause few side effects. That means eating healthy foods, exercising, getting good sleep, limiting stress, and treating other health conditions that might cause ED, like high blood pressure, heart disease, diabetes, obesity, and low testosterone, Dr. This medicine works best when you take it on an empty stomach an hour before sex. These include itraconazole Sporanox, Tolsura , ketoconazole Extina, Ketozole, others and ritonavir Norvir. Topicals tend to have a lower risk of side effects compared to oral medications, Dr.If you do buy medicines over the internet: Check to see if an online pharmacy is legitimate. Never order medicines from an online pharmacy that doesn’t . 1. It Targets the Problem and Works Quickly. Being a topical means MED targets your penis directly and offers a “quick onset of action,” Dr. Pearlman Missing: walgreens. Is there an over-the-counter Viagra? Viagra is only available with a prescription in the United States, Canada, and most other countries. Viagra is sold under .