There are many precautions and warnings to be aware of when taking Levitra. For example, numerous other medications can potentially interact with this drug. Also, Levitra does not provide any protection against sexually transmitted diseases, such as HIV. A few other Levitra precautions and warnings include people who should not take Levitra (including those who are taking a nitrate, such as nitroglycerin, for angina), the safety of taking the medicine if you have cardiovascular disease or significant heart disease risk factors, and the risk of a prolonged and sometimes painful erection (lasting longer than four hours) in some people taking the drug.
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.