Methysergide-induced valvular heart disease: a report of 2 cases.

Methysergide is a serotonin antagonist and is used as a long-term prophylactic treatment for migraine. Although many patients experience adequate control of migraine episodes, methysergide has been reported to cause retroperitoneal and pleuropulmonary fibrosis. Cardiovascular side effects mainly in the form of valvular fibrosis have been less recognized.