Avoid combining Viagra with similar treatments, e.g. avanafil (Stendra), tadalafil (Cialis) and vardenafil (Levitra). Notify your doctor of all other medications you are using, especially: bosentan (Tracleer); cimetidine (Tagamet, Tagamet HB); conivaptan (Vaprisol); imatinib (Gleevec); isoniazid (for treating tuberculosis); antidepressants such as nefazodone; antibiotics such as clarithromycin (Biaxin), erythromycin (E.E.S., EryPed, Ery-Tab, Erythrocin, Pediazole), rifampin (Rifater, Rifadin, Rifamate), or telithromycin (Ketek); antifungal medications such as itraconazole (Sporanox), ketoconazole (Nizoral), or voriconazole (Vfend); high blood pressure or prostate disorder drugs, such as alfuzosin (Uroxatral), doxazosin (Cardura), prazosin (Minipress), terazosin (Hytrin), silodosin (Rapaflo), tamsulosin (Flomax, Jalyn); heart or blood pressure medications such as amlodipine (Norvasc, Caduet, Exforge, Lotrel, Tekamlo, Tribenzor, Twynsta, Amturnide), diltiazem (Cardizem, Cartia, Dilacor, Diltia, Diltzac, Taztia, Tiazac), nicardipine (Cardene), quinidine (Quin-G), or verapamil (Calan, Covera, Isoptin, Verelan); hepatitis C medications boceprevir (Victrelis) or telaprevir (Incivek); or HIV/AIDS medicine such as atazanavir (Reyataz), darunavir (Prezista), fosamprenavir (Lexiva), indinavir (Crixivan), nelfinavir (Viracept), ritonavir (Kaletra, Norvir), saquinavir (Fortovase), or tipranavir (Aptivus).
Other medications can interact with Viagra as well.