Randomized, double-blind, crossover comparison of amlodipine and valsartan in african-americans with hypertension using 24-hour ambulatory blood pressure monitoring.

STUDY OBJECTIVE: To compare the efficacy of amlodipine and valsartan in African-American patients with hypertension using ambulatory blood pressure monitoring (ABPM).

DESIGN: Prospective, randomized, double-blind, crossover comparison study.

SETTING: University-affiliated cardiac center clinic.

PATIENTS: Twenty African-Americans (12 men, 8 women), with a history of uncomplicated hypertension (blood pressure > 140/90 mm Hg).

INTERVENTION: Patients were randomized to receive amlodipine 5 or 10 mg/day or valsartan 80 or 160 mg/day for 8-10 weeks, depending on response. Dosages were titrated to achieve a blood pressure of 140/90 mm Hg or below. For patients whose blood pressures were not controlled, hydrochlorothiazide 12.5 mg/day was added to their regimens. Patients then underwent 24-hour ABPM. After an intervening washout period during which baseline blood pressure was reestablished, patients received the other treatment.

MEASUREMENTS AND MAIN RESULTS: Mean +/- SD baseline blood pressure before the two ABPM periods were 155 +/- 12/100 +/- 8 mm Hg and 156 +/- 11/101 +/- 9 mm Hg, respectively. Fifteen (75%) patients achieved goal blood pressure with amlodipine and 14 (70%) with valsartan (p=0.62). Final daily dosages were as follows: amlodipine 5 mg in nine patients, 10 mg in five patients, and 10 mg plus hydrochlorothiazide in six patients; valsartan 80 mg in nine patients, 160 mg in four patients, and 160 mg plus hydrochlorothiazide in seven patients. Ambulatory blood pressure monitoring was not completed in three patients due to adverse effects: headache and dizziness (one patient each, amlodipine and valsartan) and hyperkalemia (one patient, valsartan). Four patients (20%) in each treatment group had drug-related adverse effects. Results of ABPM including averages for 24-hour, daytime, nighttime, first 4 hours, and last 8 hours, and trough:peak ratios were not significantly different between the amlodipine- and valsartan-based treatments.

CONCLUSION: Based on both clinic blood pressure measurements and ABPM data, amlodipine and valsartan produced similar reductions in blood pressure in African-American patients with uncomplicated hypertension.