You take one 2. In some patients, the use of VIAGRA with alpha-blockers can lead to a drop in blood pressure or to fainting medicines called HIV protease inhibitors, such as ritonavir Norvir , indinavir sulfate Crixivan , saquinavir Fortovase or Invirase , or atazanavir sulfate Reyataz some types of oral antifungal medicines, such as ketoconazole Nizoral and itraconazole Sporanox some types of antibiotics, such as clarithromycin Biaxin , telithromycin Ketek , or erythromycin other medicines that treat high blood pressure other medicines or treatments for ED VIAGRA contains sildenafil, which is the same medicine found in another drug called REVATIO. We also looked at additional services, such as access to digital pharmacies and home delivery options. 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. Kidney disease that needs to be treated with dialysis.What is Viagra? Viagra is a brand-name prescription drug that’s approved to treat erectile dysfunction (ED). With ED, you’re unable to have or maintain an erection. Viagra is approved for. 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 medicine for erectile dysfunction. If you’re holding out for a generic version of branded Viagra, you won’t have to wait much longer. Teva Pharmaceuticals plans to release its generic of the “little blue pill” as early as.