Often, these are prescribed for chest pain called angina. It might work longer if you have mild to moderate erectile dysfunction. The four main medicines taken by mouth for erectile dysfunction are: Avanafil Stendra. How oral medicines differ Each oral medicine for ED has a slightly different chemical makeup. If it is not treated right away, priapism can permanently damage your penis sudden vision loss in one or both eyes. Patients should always ask their doctors for medical advice about adverse events. As with sildenafil, a high-fat meal or alcohol keep the body from absorbing it as quickly.Currently, there are no over the counter alternatives to Viagra available. Viagra (sildenafil) is a prescription medication, meaning it’s not available over the counter from your local. Sildenafil (Viagra, Revatio) is a moderately priced drug used to treat erection problems in men. It is also used to treat pulmonary arterial hypertension, a serious heart and lung drug is more popular than comparable drugs. It is available in generic and brand versions. Generic sildenafil is covered by most Medicare and insurance plans, but . · Specifically, you may have a lower starting dosage than usual if you’re over age For example, a year-old might start at a dose of 50 milligrams (mg), while a year-old might have a.