Cardiac effects of sumatriptan: findings of Holter monitoring and review of the literature

The aim of this study was to elucidate possible electrocardiographic effects of sumatriptan in a selected group of patients with severe headache requiring in-patient treatment. The patients (n = 21) were treated with sumatriptan in addition to various other compounds and were asked to record any symptoms following the administration of sumatriptan. In addition, Holter monitoring was performed in all subjects. In agreement with other studies, the adverse events reported by the patients were not related to ECG changes and, vice versa, ECG changes were not accompanied by clinical symptoms. The Holter findings before and after administration of sumatriptan were significantly different in three patients, i.e. recurrent episodes of ST depression and increase in extrasystoles. These changes occurred within a period of 1.45 to 18 hours and were not reproducible when Holter monitoring was repeated without sumatriptan. Even though the findings might be explained by spontaneous variability of Holter monitoring or other factors, this study does not definitely discount the possibility that sumatriptan may cause ST segment changes and increase pre-existing extrasystoles. Controlled studies are required to clarify this issue.