Effect of hypotensive drugs on the circadian blood pressure pattern in essential hypertension: a comparative study.

To compare the effect of four drug groups on the ambulatory circadian blood pressure (BP) pattern, amiloride hydrochlorothiazide, atenolol, nifedipine, and perindopril (5/50 mg/d, 100 mg/d, 40 mg/d, and 4 mg/d respectively, for 14 days) were alternated in each of 20 essential hypertension patients. Diuretics induced the largest (P < 0.05) drop in mean 24-hour systolic BP (-12 mmHg, P < 0.001). Atenolol reduced only its standard deviation, and nifedipine reduced only the mean daytime systolic BP (P < 0.05). The mean 24-hour diastolic BP was equally reduced by all drugs except nifedipine, which only reduced (P < 0.05) the mean daytime value. The mean 24-hour heart rate was decreased by atenolol (P < 0.001), increased by diuretics (P < 0.05), and unchanged with perindopril, while nifedipine increased (P < 0.05) only its night-time value. In conclusion, diuretics were the strongest agents in reducing systolic BP, atenolol the only agent that reduced variability, perindopril the only agent that did not affect the heart rate, and nifedipine reduced only daytime BP values.