Among the people who should not take vardenafil are those who are allergic to vardenafil or any component of Levitra and those who are taking a nitrate (such as nitroglycerin) for angina. Some of the conditions you should let your healthcare provider know about before you take vardenafil include heart disease, high blood pressure, and kidney disease that requires dialysis. A few other precautions and warnings for vardenafil include potential drug interactions; the risk of a prolonged, sometimes painful erection (lasting longer than four hours) in some people taking the medicine; and the fact that vardenafil does not provide protection against sexually transmitted diseases, such as HIV.
A rare heart condition known as prolongation of the QT interval (long QT syndrome); also tell your doctor if anyone in your family has this condition.
It is also important to tell your healthcare provider about all the medicines you take, including prescription and non-prescription medicines, antacids, vitamins, and herbal supplements.