But, some side effects, including flushing, heartburn, sinus congestion, and headaches, might prevent some men from taking them even though they work well. They enhance the effects of a chemical the body makes that relaxes muscles in the penis, called nitric oxide. Box , Mission, KS If your pharmacy does not participate, you may be able to submit a request for a rebate in connection with this Savings Offer. How oral medicines differ Each oral medicine for ED has a slightly different chemical makeup. Stop taking VIAGRA and call your healthcare provider right away if you have any sudden vision loss sudden hearing decrease or hearing loss. This site is intended only for U.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 says. “People love . Drug Images What is Viagra? If you have erectile dysfunction (ED), your doctor may recommend that you take Viagra. It’s a prescription drug that’s used in adult males* with . Sildenafil (Viagra, Revatio) is a moderately priced drug used to treat erection problems in is also used to treat pulmonary arterial hypertension, a serious heart and lung .