Effects of short- and long-acting calcium channel blockers on the relationship between blood pressure and physical activity

Calcium channel blockers are widely used as antihypertensive drugs. However , there is some controversy as to how they should be used. Our first aim wa s to clarify how the dihydropyridine calcium channel blocker, benidipine, a ffects the quantitative relationship between blood pressure (BP) and physic al activity. The second aim was to determine whether there is a relationshi p between systolic blood pressure (SBP) and physical activity in patients w ith hypertension when treating with a short-acting (nifedipine) or long-act ing (benidipine) calcium channel blocker. In Study 1, ambulatory BP and phy sical activity were measured simultaneously in 27 patients with hypertensio n before and after 6 months with benidipine. In Study 2, ambulatory BP and physical activity were measured simultaneously in 16 patients with hyperten sion before (placebo) and after 6 weeks of crossover treatment with nifedip ine and benidipine. In Study 1, there was no difference in the SEP change c aused by physical activity between the pre- and posttreatment periods. In S tudy 2, SEP was significantly related to physical activity in the placebo ( 16/16) and benidipine (16/16) groups but not in the nifedipine (12/16) grou p. The lowest BP during daytime and nighttime in the nifedipine group were significantly lower than those in the benidipine group. Plasma renin activi ty (ng/mL/h) was significantly higher in the nifedipine group(l.20 +/- 1.05 ) than in the placebo (0.57 +/- 0.59) and benidipine (0.75 +/- 0.78) groups . These findings indicate that nifedipine might interfere with the adaptati on mechanism of BP changed by physical activity and that the activated reni n-angiotensin system might cause cardiac events. (C) 2001 American Journal of Hypertension, Ltd.