Efficacy of different drug classes used to initiate antihypertensive treatment in black subjects - Results of a randomized trial in Johannesburg, South Africa

Background: Thiazides are recommended to initiate antihypertensive drug tre atment in black subjects. Objectives: To test the efficacy of this recommendation in a South African black cohort. Methods: Men and women (N=409), aged 18 to 79 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 gastroin testinal therapeutic system (30 mg/d, n=233), sustained-release verapamil h ydrochloride (240 mg/d, n=58), hydrochlorothiazide (12.5 mg/d, n=58), or en alapril maleate (10 mg/d, n=600). If the target of reducing daytime diastol ic blood pressure below 90 mm Hg was not attained, the first-line drugs wer e titrated up and after 2 months other medications were added to the regime n. Results: While receiving monotherapy (2 months, n=366), the parents' systol ic and diastolic decreases in daytime blood pressure averaged 22/14 mm Hg f or nifedipine, 17/11 mm Hg for verapamil 12/8 mm Hg for hydrochlorothiazide , and 5/3 Hg for enalapril. At 2 months the blood pressure of more patients treated with nifedipine was controlled: 133 (63.3%, P less than or equal t o .03) vs 20 (39.9%) receiving verapamil, 2.1 (40.4%) receiving hydrochloro thiazide, and 11 (20.8%) receiving enalapril. At 13 months (n=257), more pa tients (P<.001) continued receiving monotherapy with nifedipine (94/154 [61 .0%]) or verapamil (22/35 [62.9%]) than hydrochlorothiazide (10/39 [25.6%]) or ventricular mass (P<.001) with no between-group differences was achieve d at 4 and 13 months. Conclusions: In contrast to current recommendations, calcium channel blocke rs are more effective than thiazides as initial treatment in black subjects with hypertension. If treatment is started with thiazides or converting-en zyme inhibitors, combination therapy is more likely to be required to contr ol blood pressure and reduce left ventricular mass.