Recent heart or blood vessel problems. Stop taking VIAGRA and call your healthcare provider right away if you have any sudden vision loss sudden hearing decrease or hearing loss. 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. 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. Patients should always ask their doctors for medical advice about adverse events.Last updated: June 14, If you’re looking for a less costly Viagra, you might want to ask your doctor about sildenafil. It’s the active ingredient in both branded Viagra and the drug. Don’t be fooled into buying “herbal viagra.” Never take any medicines that claim to be the “herbal” or nonprescription version of an oral medicine for ED. These aren’t an effective . Generic Viagra (sildenafil) is an alternative to the branded Viagra drug that can be used for treating erectile dysfunction (ED). It’s now sold by many manufacturers, including online.