In the event of an erection that persists longer than 4 hours, the patient should seek immediate medical assistance. Prolonged erection greater than 4 hours and priapism (painful erections greater than 6 hours in duration) have been reported infrequently since market approval of Fildena. A starting dose of 25 mg of Fildena should be considered in patients taking erythromycin or strong CYP3A4 inhib