The four main medicines taken by mouth for erectile dysfunction are: Avanafil Stendra. Kidney disease that needs to be treated with dialysis. Oral medicine for ED also might not be safe or work well if you have: Very low blood pressure, called hypotension, or uncontrolled high blood pressure, called hypertension. You can take it in a small dose daily or in a larger dose as needed. Avanafil Stendra.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, . Generic versions of sildenafil, vardenafil and tadalafil are available. When oral medications might not be safe Check with your health care team before you take any . Drug Facts Common Brands Viagra Drug Class PDE-5 inhibitor Controlled Substance Classification Not a controlled medication Generic Status Lower-cost generic .