Viagra (sildenafil citrate) is effective in the treatment of male impotence, or impotence (ED). Your physician should learn about any various other medications you are taking presently to stop drug communications from taking place. Your doctor needs to understand regarding any one of the following medicines in case you are currently taking them: alpha blockers, erythromycin, HIV protease inhibitors, anticoagulants (warfarin), barbiturates, 'beta' blockers, cimetidine, other erectile dysfunction therapies, amlodipine, medications for hypertension, seizure medications, antifungals (itraconazole, ketoconazole), rifabutin and rifampin. It's a great concept to make a checklist of drugs you are taking and demonstrate to your medical company. Your dose may be readjusted or you will be unable to take this medicine.