Once-daily dihydropyridine calcium channel blockers appeared to lower blood pressure by a relatively constant amount throughout the 24-hour dosing interval .
Six dihydropyridine calcium channel blockers studied in this review lowered blood pressure by a relatively similar amount each hour over the course of 24 hours .
BACKGROUND Calcium channel blockers are a heterogeneous class of drugs , including dihydropyridine and non-dihydropyridine subgroups , commonly used in the treatment of hypertension .
A systematic review of the 24-hour time course of the blood pressure-lowering effect has not been published .
OBJECTIVES To assess how much variation there is in hourly systolic and diastolic blood pressure lowering by dihydropyridine calcium channel blockers over a 24-hour period in people with hypertension aged 18 years or over , with baseline systolic blood pressure of at least 140 mmHg or diastolic blood pressure of at least 90 mmHg , or both .
The 24-Hour Efficacy of a New Once-Daily Formulation of Nifedipine
Summary Nifedipine GITS ( Gastro-Intestinal Therapeutic System ) is a recently launched long-acting formulation of nifedipine . The aim of the Italian  Nifedipine GITS Study was to determine the duration of the antihypertensive effect of once-daily nifedipine GITS in out patients with essential hypertension . After a 2-week placebo run-in period , 126 patients with mild to moderate essential hypertension ( diastolic BP 95 to 114 mm Hg ) were r and omised to receive nifedipine GITS 30 mg ( n = 42 ) , nifedipine GITS 60 mg ( n = 42 ) or placebo ( n = 42 ) , once daily in a double-blind fashion for 4 weeks . At the end of the run-in and treatment periods ,  ambulatory BP monitoring  was performed ( Spacelabs 90202 or 90207 device ) to provide regular 15-minute BP readings for 24 to 36 hours . In the 81 patients with at least 24 hours of valid ambulatory BP data , the average systolic and diastolic BP changes after treatment with nifedipine GITS 30 mg ( n = 25 ) , nifedipine GITS 60 mg ( n = 28 ) and placebo ( n = 28 ) were −16.5/−10.8 , −16.3/−10.0 and + 0.4/+0.9 mm Hg , respectively . BP changes with nifedipine GITS differed significantly ( p < 0.01 ) from those with  placebo . Heart rate was not significantly altered by nifedipine GITS . The effects of nifedipine GITS and placebo on ambulatory BP 24 hours and 36 hours after the last dose were evaluated in 56 patients with complete 36-hour ambulatory BP profiles . After 24 hours , both doses of nifedipine GITS caused significant ( p < 0.01 ) reductions in systolic and diastolic BP . After 36 hours , the reduction in ambulatory BP induced by nifedipine GITS was less pronounced than after 24 hours ; the changes in systolic BP produced by both nifedipine GITS doses were still significant ( p < 0.01 ) , whereas the change in diastolic BP was significant only after the 60 mg dose ( p < 0.05).Trough : peak ratios of the antihypertensive effect of nifedipine GITS were calculated by comparing the highest average hourly BP reduction between 2 and 6 hours postdose ( peak reduction ) and the BP change at 24 hours postdose ( trough reduction ) in the 81 patients with valid 24-hour ambulatory BP data . Trough : peak ratios were 90.5 % ( systolic BP ) and 76.3 % ( diastolic BP ) for nifedipine GITS 30 mg , and 109.3 % ( systolic BP ) and 98.6 % ( diastolic BP ) for nifedipine GITS 60 mg . The ratios were further increased if placebo-induced BP changes were taken into account . In conclusion , the antihypertensive effect of nifedipine GITS is maintained for more than 24 hours postdose , and is uniform over this period , without any undue imbalance between the peak BP effect and that observed immediately before the subsequent dose
Once-daily dihydropyridine calcium channel blockers appeared to lower blood pressure by a relatively constant amount throughout the 24-hour dosing interval .
Six dihydropyridine calcium channel blockers studied in this review lowered blood pressure by a relatively similar amount each hour over the course of 24 hours .
BACKGROUND Calcium channel blockers are a heterogeneous class of drugs , including dihydropyridine and non-dihydropyridine subgroups , commonly used in the treatment of hypertension .
A systematic review of the 24-hour time course of the blood pressure-lowering effect has not been published .
OBJECTIVES To assess how much variation there is in hourly systolic and diastolic blood pressure lowering by dihydropyridine calcium channel blockers over a 24-hour period in people with hypertension aged 18 years or over , with baseline systolic blood pressure of at least 140 mmHg or diastolic blood pressure of at least 90 mmHg , or both .