Intravenous labetalol compared with intravenous nicardipine in the management of hypertension in critically ill patients.

BACKGROUND: Critically ill patients with acute hypertension often require titratable rapid blood pressure (BP) reductions using parenteral administration of drugs. There are few comparative studies available to make informed drug product selection decisions. The purpose of this study was to evaluate the short-term clinical outcomes and costs of intravenous labetalol or intravenous nicardipine in the management of hypertension in critically ill patients.
METHODS: This study was a retrospective analysis of consecutive patients receiving intravenous labetalol or intravenous nicardipine in the intensive care unit with acute elevations in either systolic (>160 mm Hg) or diastolic (>90 mm Hg) BP. Patient demographics, clinical characteristics, and short-term clinical outcomes were abstracted from the medical record. Hospital costs were calculated from hospital billing forms.
RESULTS: A total of 189 patients receiving labetalol and 193 patients receiving nicardipine were included in the analysis. The average hourly dose was 37.3 ± 9.4 mg/h for labetalol compared with 7.1 ± 5.6 mg/h for nicardipine (P < .001). The average total dose of labetalol was 170.9 ± 32.6 mg compared with 112.2 ± 29.1 mg for nicardipine (P = .02). The duration of therapy was significantly shorter for labetalol (8.2 ± 6.2 hours) compared with nicardipine (15.8 ± 4.4 hours) (P = .03). There were a greater number of dose titrations with labetalol (6.1 ± 6.2) than with nicardipine (4.7 ± 4.9), but this difference was not significantly different (P = .29). There were no significant differences in the magnitude of the average change in systolic (P = .79) or diastolic (P = .82) BP between labetalol and nicardipine. The proportion of patients achieving their BP targets was significantly greater with nicardipine (83%) than with labetalol (67%) (P = .04). The proportion of patients requiring an alternate antihypertensive agent was significantly greater with labetalol than with nicardipine (31% vs 17%; P = .02). The total number of all-cause adverse events was significantly greater with labetalol (61%) than with nicardipine (48%) (P = .04). Labetalol was associated with a significantly greater incidence of hypotension and bradycardia or atrioventricular block compared with nicardipine. There was no significant difference in the frequency of other adverse events between these 2 drugs. The median hospital costs were not significantly different between patients receiving labetalol and patients receiving nicardipine.
CONCLUSION: Our study suggests that nicardipine is a more effective antihypertensive agent than labetalol in an unselected group of patients who develop hypertension in the intensive care unit setting. A major advantage of nicardipine compared with labetalol was fewer adverse effects. Nicardipine was associated with less hypotension and bradycardia or atrioventricular block, resulting in a lower rate of drug discontinuation compared with labetalol.