COMPARISON OF THE EFFICACY OF DIHYDROPYRIDINE CALCIUM-CHANNEL BLOCKERS IN AFRICAN-AMERICAN PATIENTS WITH HYPERTENSION

Background: Hypertension is a prevalent disease among African American s, and successful treatment rates are low. Since calcium channel block ers are well-tolerated and efficacious in African Americans, we undert ook this study to compare the efficacy, safety, and tolerability of 3 commonly prescribed calcium channel blockers: amlodipine besylate (Nor vasc), nifedipine coat core (CC) (Adalat CC), and nifedipine gastroint estinal therapeutic system (GITS) (Procardia XI). Methods: One hundred ninety-two hypertensive patients across 10 study centers were randoml y assigned to double-blind monotherapy with amlodipine besylate (5 mg/ d), nifedipine CC (30 mg/d), or nifedipine GITS (30 mg/d) for 8 weeks. Patients not achieving therapeutic response after 4 weeks had their d ose doubled for the next 4 weeks. The primary end point was a comparis on of the average reduction (week 8 minus baseline) in 24-hour ambulat ory diastolic blood pressure (DBP). Secondary end points included a co mparison of average 24-hour ambulatory systolic blood pressure (SBP), office SEP or DBP reduction, responder rates, safety, and tolerability . Results: One hundred sixty-three patients were evaluable for efficac y after 8 weeks. There was no significant difference in the average 24 -hour ambulatory DBP (-8.5, -9.0, and -6.1 mm Hg, respectively) or SEP (-14.3, -15.7, and -11.8 mm Hg, respectively) reduction. Average offi ce SEP and DBP were reduced to a comparable degree (19-22 mm Hg [P = . 50] and 12-14 mm Hg [P = .51], respectively). Responder rates (DBP <90 or reduced by greater than or equal to 10 mm Hg) were similar (P = .3 8). Discontinuation rates and adverse event frequency were distributed similarly across the 3 treatment groups. Conclusion: The efficacy, sa fety, and tolerability of the 3 dihydropyridine calcium channel blocke rs are equivalent in African Americans with stages 1 and 2 hypertensio n.