Beta blockers are commonly used to attenuate the transient increase in heart rate (HR) and blood pressure (BP) that accompany electroconvulsive therapy (ECT). Recent reports have suggested that several beta blockers have anticonvulsant properties and hence could be countertherapeutic with ECT. In a randomized, double-blind controlled study of the dose response effects of intravenous labetalol on ECT hemodynamics and seizure duration, labetalol exhibited dose-dependent reduction in HR and rate pressure product (RPP) at the 5 and 10 mg doses compared to placebo. However, no significant differences between labetalol 5 mg, 10 mg, or placebo were found on BP or seizure duration.