A wide variety of vasoactive drugs have been used to treat the acute hypertensive response to electroconvulsive therapy (ECT). We designed this randomized, double-blind, saline-controlled, crossover study to compare three different doses of nicardipine when administered before the ECT stimulus. Twenty-five patients undergoing a series of 4 ECT treatments received bolus injections of either saline or nicardipine 20, 40, or 80 mug/kg IV in a random sequence during a standardized methohexital (1 mg/kg) and succinylcholine (1 mg/kg) anesthetic technique. The mean arterial blood pressure (MAP) and heart rate values were recorded at specific time intervals, as were the duration of seizure activity and the need for rescue labetalol. Both the 40 and 80 mug/kg doses of nicardipine reduced the percentage increase in MAP above the baseline value compared with the saline group (7% and 7% versus 30%, respectively). Nicardipine 40 and 80 mug/kg were also associated with a significant reduction in the need for labetalol (7 +/- 3 mg and 5 +/- 0 mg versus 22 +/- 10 mg in the saline group). Compared with the 40 mug/kg dose, nicardipine 80 mug/kg was associated with a more rapid heart rate at the time the ECT stimulus was applied. The 80 mug/kg dose was also associated with a reduced MAP value on awakening compared with the baseline value (91 +/- 12 mm Hg versus 102 +/- 8 mm Hg). We conclude that a bolus injection of nicardipine 40 mug/kg IV immediately before the ECT stimulus was optimal for controlling the acute hemodynamic response to ECT treatments.