Circadian rhythm of blood pressure and calcium entry blockade: a chronobiological study with nitrendipine in essential hypertension.

In order to evaluate the chronobiologic effect of nitrendipine. 27 patients with mild-to-moderate arterial essential hypertension were studied. Alter randomi/ed administration of 20 mg of nitrendipine and placebo, systolic and diastolic blood pressure (SBP and DBP. respectively) and heart rate (1 IR) were measured for 24 h using an automatic noninvasive device. The data of the time series were statistically analy/ed by single- and mean cosinor methods (obtaining mesor. amplitude, and acrophase) and by ANOVA and Student’s paired / test. Nitreiulipine significantly reduced the SBP and DBP mesors without all’ccting the HR mesor. and reduced the SBP ami DBP amplitudes while increasing the HR amplitude. Alter placebo, group circadian rhythms were observed for SBP. DBP. and HR and maintained alter nitrendipine. In conclusion, a single-dose administration of nitrendipine is effective in lowering blood pressure. The increased HR amplitude is probably due to a tachycardic reaction. the preserva...