The most common side effects of this medicine are flushing, headache, blurred vision, muscle pain, stomach upset, and rash. Talk to your doctor if the side effects bother you or will not go away.
This medicine is not intended for use by women and men should avoid using any other medicines to treat impotence without talking to a doctor. It can be dangerous to take it along with medicines called nitrates (often given for chest pain). Do not take this medicine if you have severe heart or liver problems, if you have recently had a stroke or heart attack or if you have low blood pressure. Let your doctor know if you suffer from these or any other health problems before taking it. You should not drive if this medicine makes you feel dizzy. Avoid drinking alcohol while taking this medicine as it can lead to side effects.