We considered cost, medications available, and whether generic versions were offered to help reduce costs. Generic versions of sildenafil, vardenafil and tadalafil are available. These include itraconazole Sporanox, Tolsura , ketoconazole Extina, Ketozole, others and ritonavir Norvir. Generic vs. Insurance: If you plan to use insurance, make sure the online provider accepts it.Viagra is used to treat erectile dysfunction (ED). This is unlike Revatio, which is used to treat pulmonary arterial hypertension. (This is a condition that causes Missing: free. Still, if your doctor says it’s okay for you to use and you end up paying out-of-pocket, you can still get the generic for a lot less than Viagra. According to price . Typical dosing for Sildenafil (Viagra) The typical dose is to take 50 mg of sildenafil (Viagra) by mouth, about 1 hour before sex, as needed. The maximum .