| Abstract
| - Twenty-four patients completed a double-blind, randomized clinical trial comparing the effects of nifedipine GITS (N) and verapamil SR (V) on blood pressure (BP) control and exercise performance. After a 2-week placebo phase, all subjects had measurements of V02 max, maximal workload, and endurance time. They were then randomized to either Ν (30 to 90 mg/day) or V (240 to 480 mg/ day) and retested when BPs had stabilized. At rest, Ν lowered systolic (S) BP by 12 mm Hg (P = .02 compared to baseline) and diastolic (D) BP by 11 mm Hg (P = .001). V lowered SBP by 8 mm Hg (P = .013) and DBP by 11 mm Hg (P = .002). Neither drug affected resting heart rate. V significantly decreased resting epinephrine (P = .05) and there was a tendency for V to reduce norepinephrine (P = .07) and dopamine (P = .08). Ν tended to increase plasma renin activity (P = .07). During graded cycle ergometry N, compared with placebo, significantly lowered DBP at all exercise levels (P = .011), but had no significant effect on heart rate (HR), SBP, or heart rate pressure product (HRPP). Pulse pressure (PP) was significantly increased (P = .045), which was most noticeable at high exercise levels. Compared with placebo, V caused a marked reduction of exercise HR (P < .001), which was more pronounced at high levels, SBP (P = .004), DBP (P = .004), mean arterial pressure (MAP) (P = .001), and HRPP (P < .001). V caused a significantly greater reduction in HR (P = .069), SBP (P = .013), MAP (P = .056), PP (P = .023), and HRPP (P < .001) than N. There were no differences in DBP reduction. At maximum exercise, Ν significantly increased plasma norepinephrine (P = .04). Neither drug affected V 0 2 m a x / exercise duration, or maximum workload. In summary, both Ν and V lowered resting SBP and DBP. During graded cycle ergometry, both drugs effectively lowered DBP, but only V lowered SBP, PP, and HRPP. V is the preferred drug for those who participate in vigorous activity. Am J Hypertens 1993;6:1025-1032
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