Efficacy of different drug classes used to initiate antihypertensive treatment in black subjects: results of a randomized trial in Johannesburg, South Africa
Sareli, P.; Radevski, I.V.; Valtchanova, Z.P.; Libhaber, E.; Candy, G.P.; Den Hond, E.; Libhaber, C.; Skudicky, D.; Wang, J.G.; Staessen, J.A.
Archives of Internal Medicine 161(7): 965-971
2001
ISSN/ISBN: 0003-9926 PMID: 11295959 Document Number: 540079
Background: Thiazides are recommended to initiate antihypertensive drug treatment in black subjects. Objective: To test the efficacy of this recommendation in a South African black cohort. Methods: Men and women (N=409), aged 18 to 70 years, with a mean ambulatory daytime diastolic blood pressure between 90 and 114 mm Hg, were randomized to 13 months of open-label treatment starting with the nifedipine gastrointestinal therapeutic system (30 mg/d, n=233), sustained-release verapamil hydrochloride (240 mg/d, n=58), hydrochlorothiazide (12.5 mg/d, n=58), or enalapril maleate (10 mg/d, n=60). If the target of reducing daytime diastolic blood pressure below 90 nun Hg was not attained, the first-line drugs were titrated up and after 2 months other medications were added to the regimen. Results: While receiving monotherapy (2 months, n=366), the patients' systolic and diastolic decreases in daytime blood pressure averaged 22/14 mm Hg for nifedipine, 17/11 mm Hg for verapamil, 12/8 mm Hg for hydrochlorothiazide, and 5/3 mm Hg for enalapril. At 2 months the blood pressure of more patients treated with nifedipine was controlled: 133 (63.3%, Pltoreq.03) vs 20 (39.9%) receiving verapamil, 21 (40.4%) receiving hydrochlorothiazide, and 11 (20.8%) receiving enalapril. At 13 months (n=257), more patients (P<.001) continued receiving monotherapy with nifedipine (94/154 (61.0%)) or verapamil (22/35 (62.9%)) than hydrochlorothiazide (10/39 (25.6%)) or enalapril (1/29 (3.4%)). A sustained decrease of left ventricular mass (P<.001) with no between-group differences was achieved at 4 and 13 months. Conclusions: In contrast to current recommendations, calcium channel blockers are more effective than thiazides as initial treatment in black subjects with hypertension. If treatment is started with thiazides or converting-enzyme inhibitors, combination therapy is more likely to be required to control blood pressure and reduce left ventricular mass.