Sildenafil citrate (
) is a medication used to treat male sexual dysfunction, more specifically erectile dysfunction. As with all medications, there are potential side effects to using it. Some of the more common side effects include headache, flushing, indigestion, nasal congestion, and abnormal vision such as blurriness. Side effects that are less common but more serious include priapism (prolonged and painful erection), hearing loss, and heart attacks. If you experience any side effects, consult your doctor.