Viagra (sildenafil) is a potent prescription medication efficient in helping the patients taking it to obtain a firmer erection. As most drugs, Viagra has been reported to interact with some other medicines. The list of drugs Viagra may interfere with is quite long, but here are the most commonly prescribed ones: bosentan, phenytoin, carbamazepine, other erectile dysfunction treatment drugs, barbiturates, amlodipine, anticoagulants, efavirenz, alpha blockers, high blood pressure medications, nevirapine, phenobarbital, rifabutin, medicines for seizures, tamsulosin, HIV protease inhibitors, cimetidine, erythromycin, antifungals (itraconazole, ketoconazole), beta blockers etc. If you are taking some medicine and are not sure taking it along with Viagra will be safe enough, you can always consult your health care provider or your pharmacist for more information. Make sure your health care provide is aware of the fact you have any of the following health conditions that may affect the efficiency of your treatment with Viagra: high cholesterol or blood circulation problems, bleeding disorder, chest pain, pulmonary veno-occlusive disease, blood cell problems, heart attack, eye disease such as retinitis pigmentosa, conditions affecting the shape of the penis, heart, kidney, or liver disease, stroke, high or low blood pressure, stomach ulcer, irregular heartbeat. If you have any other health conditions that you think may be of importance report them as well to make sure you get the full benefits of your treatment.