Tadalafil Cialis. Generic versions of sildenafil, vardenafil and tadalafil are available. Some people may also have ringing in their ears tinnitus or dizziness. The information provided is for educational purposes only and is not intended to replace discussions with a healthcare provider. 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. ED can sometimes signal an underlying medical problem, like heart disease or diabetes , that needs to be treated separately. These medicines all work well for ED.Most popular Safeway $ retail Save 94% $ Get free savings Low price Walgreens $ retail Save 94% $ Get free savings directions Closest store Rite Aid. Avanafil (Stendra). Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that . If you’re interested in buying Viagra online, five of the best options available are Hims, Roman, Lemonaid, Optum Store, and REX MD. Read on for full details on the process .