The management of acute hypertension in patients with renal dysfunction: labetalol or nicardipine?

Study objectives: To compare the safety and efficacy of U.S. Food and Drug Administration (FDA)-recommended doses of labetalol and nicardipine for hypertension (HTN) management in a subset of patients with renal dysfunction (RD).

Design: Randomized, open label, multicenter prospective clinical trial.

Setting: Thirteen United States tertiary care emergency departments.

Patients or participants: Subgroup analysis of the Evaluation of IV Cardene (Nicardipine) and Labetalol Use in the Emergency Department (CLUE) clinical trial. The subjects were 104 patients with RD (i.e., creatinine clearance < 75 mL/min) who presented to the emergency department with a systolic blood pressure (SBP) ≥ 180 mmHg on 2 consecutive readings and for whom the emergency physician felt intravenous antihypertensive therapy was desirable.

Interventions: The FDA recommended doses of either labetalol or nicardipine for HTN management.

Measurements: The number of patients achieving the physician's predefined target SBP range within 30 minutes of treatment.

Results: Patients treated with nicardipine were within target range more often than those receiving labetalol (92% vs. 78%, P = 0.046). On 6 SBP measures, patients treated with nicardipine were more likely to achieve the target range on either 5 or all 6 readings than were patients treated with labetalol (46% vs. 25%, P = 0.024). Labetalol patients were more likely to require rescue medication (27% vs. 17%, P = 0.020). Adverse events thought to be related to either treatment group were not reported in the 30-minute active study period, and patients had slower heart rates at all time points after 5 minutes (P < 0.01).

Conclusions: In severe HTN with RD, nicardipine-treated patients are more likely to reach a target blood pressure range within 30 minutes than are patients receiving labetalol.

Clinical implications: Within 30 minutes of administration, nicardipine is more efficacious than labetalol for acute blood pressure control in patients with RD.