Viagra.

Viagra (sildenafil) is a popularly prescribed anti-impotence medicine that works by increasing the blood flow to the tissues of the penis and then preventing the blood from escaping back into the body too soon therefore providing the patient with several hours of efficiency. This drug is not supposed to be combined with isosorbide mononitrate, butyl nitrate, nitroglycerin, amyl nitrate, or isosorbide dinitrate (nitrate based meds) as dangerous interactions are possible. Tell your doctor if you are using barbiturates, rifabutin, rifampin, anticoagulants, amlodipine, medications for high blood pressure, alpha blockers, erythromycin, bosentan, cimetidine, HIV protease inhibitors, seizure medications, other erectile dysfunction meds, certain antifungals, nevirapine, beta blockers, or efavirenz, as you may need a dose adjustment to make sure there are no interactions possible that can affect the success of either of your treatments. Call your doctor if you experience chest pain, lightheadedness, sudden severe loss of vision, fainting, ringing in ears, priapism, itching or burning during urination, rash, shortness of breath, blurred vision, loss of hearing, or dizziness, as those are serious side effects possible in some rare cases.