People with liver or kidney disease should avoid taking Cenforce pills. They should also consult their physician before taking it. The drug may interact with certain medications, especially nitrate-based medicines that treat chest pain and angina. If you have liver or kidney disease, it's best to consult with your doctor before taking it. Also, avoid taking more than one tablet a day. Taking more than one tablet may increase your risk of side effects such as flushing and headaches.