The safety of cumulative doses of labetalol in perioperative hypertension.

Intravenous labetalol is commonly used in the management of hypertensive emergencies or urgencies as well as postoperative hypertension. The maximum recommended dose in any clinical setting is 300 mg in 24 hours. The safety of administering high doses of intravenous labetalol (greater than 300 mg in 24 hours) was evaluated in neurosurgical patients (n = 9). During 15 distinct periods of 24 hours or less, the mean dose of labetalol given was 623 +/- 86 mg. Adverse hemodynamic and biochemical effects were minor and easily reversible. Intravenous labetalol can safely be used in doses exceeding 300 mg per 24 hours in neurosurgical patients.