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 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 mm 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%, P</=.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.
Sareli
P
P
Department of Cardiology, Chris Hani-Baragwanath Hospital, University of the Witwatersrand, PO Bertsham, Johannesburg 2013, South Africa. psareli@iafrica.com
Radevski
I V
IV
Valtchanova
Z P
ZP
Libhaber
E
E
Candy
G P
GP
Den Hond
E
E
Libhaber
C
C
Skudicky
D
D
Wang
J G
JG
Staessen
J A
JA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000145:classification* / Q000494:pharmacology / Q000627:therapeutic use*; D000959:Antihypertensive Agents / Q000145:classification* / Q000494:pharmacology / Q000627:therapeutic use*; D044383:Black People; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000145:classification* / Q000494:pharmacology / Q000627:therapeutic use*; D003971:Diastole / Q000187:drug effects; D004232:Diuretics; D004359:Drug Therapy, Combination; D004656:Enalapril / Q000145:classification* / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006852:Hydrochlorothiazide / Q000145:classification* / Q000494:pharmacology / Q000627:therapeutic use*; D006973:Hypertension / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy* / Q000235:genetics*; D017379:Hypertrophy, Left Ventricular / Q000209:etiology / Q000473:pathology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000145:classification* / Q000494:pharmacology / Q000627:therapeutic use*; D017410:Practice Guidelines as Topic; D016016:Proportional Hazards Models; D049993:Sodium Chloride Symporter Inhibitors / Q000145:classification* / Q000494:pharmacology / Q000627:therapeutic use*; D013019:South Africa; D013997:Time Factors; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000145:classification* / Q000494:pharmacology / Q000627:therapeutic use*; D014700:Verapamil / Q000145:classification* / Q000494:pharmacology / Q000627:therapeutic use*
D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D004232:Diuretics; D049993:Sodium Chloride Symporter Inhibitors; D014665:Vasodilator Agents; D006852:Hydrochlorothiazide; D004656:Enalapril; D014700:Verapamil; D009543:Nifedipine