Effects of antihypertensive drugs on SBP variability are dose-dependent and persist when used in combinations .
Use of a high dose of a calcium channel blocker alone or in combination with other agents is therefore likely to be particularly effective in prevention of stroke
BACKGROUND AND PURPOSE Recent studies have shown that visit-to-visit blood pressure variability is a powerful risk factor for stroke , is reduced by calcium channel blockers and diuretics , and increased by β-blockers .
However , it is unknown whether these effects are dose-dependent and persist in combination with other drugs .
Comparative effects of felodipine ER, amlodipine and nifedipine GITS on 24 h blood pressure control and trough to peak ratios in mild to moderate ambulatory hypertension: a forced titration study.
OBJECTIVE To evaluate the 24 h antihypertensive efficacy and duration of action of felodipine extended release ( ER ) in comparison with two other long acting dihydropyridine calcium antagonists , amlodipine and nifedipine gastrointestinal therapeutic system ( GITS ) , in patients with mild to moderate essential hypertension substantiated by ambulatory blood pressure ( BP ) monitoring . DESIGN R and omized , forced titration , parallel group study . Clinic BP was measured at every patient 's visit , and 24 h ambulatory BP was monitored at baseline and at the end of each dose-titration period . SETTING Single centre : hypertension research unit in Quebec City , Quebec . PATIENTS There were 89 patients enrolled into the study . Eighty-four eligible patients were r and omized , and 83 completed the study and were included in the final efficacy analysis . INTERVENTIONS Following a two-to four-week washout period ( baseline ) , patients were r and omly allocated to receive felodipine ER 5 mg , amlodipine 5 mg or nifedipine GITS 30 mg for four weeks ( low dose ) . All study patients had their daily dose doubled to felodipine ER 10 mg , amlodipine 10 mg or nifedipine GITS 60 mg for a further four weeks ( high dose ) . MAIN RESULTS Significant ( P < 0.001 ) and similar changes from baseline in clinic BP were observed in all treatment groups for low and high doses . Ambulatory BP profiles showed comparable blood pressure reductions with felodipine ER and amlodipine , and a trend towards a lesser reduction with nifedipine GITS during 24 h , daytime and night-time periods . BP loads were similarly reduced with the three treatments . Trough to peak ratios ( T : Ps ) were calculated from 24 h ambulatory BP curves according to two different approaches : for diastolic and systolic BP , respectively , the global approach produced T : Ps of 0.49 and 0.50 with felodipine ER 5 mg ; 0.50 and 0.34 with felodipine ER 10 mg ; 0.70 and 0.60 with amlodipine 5 mg ; 0.88 and 0.82 with amlodipine 10 mg ; 0.65 and 0.55 with nifedipine GITS 30 mg ; 0.68 and 0.53 with nifedipine GITS 60 mg . T : Ps in the individual approach were 0.07 and 0.10 with felodipine ER 5 mg ; 0.23 and 0.31 with felodipine ER 10 mg ; 0.22 and 0.31 with amlodipine 5 mg ; 0.45 and 0.58 with amlodipine 10 mg ; 0.27 and 0.31 with nifedipine GITS 30 mg ; and 0.24 and 0.40 with nifedipine GITS 60 mg . CONCLUSION There was no evidence in this study of a difference among felodipine ER , amlodipine and nifedipine GITS in lowering ambulatory or clinic BP . Treatment based on ambulatory BP may be preferable to treatment guided by T : Ps because ambulatory BP is firmly established as a predictor of cardiovascular risk . Furthermore , there is no consensus on how to calculate T : Ps , and different methods of calculation may give divergent results
Effects of antihypertensive drugs on SBP variability are dose-dependent and persist when used in combinations .
Use of a high dose of a calcium channel blocker alone or in combination with other agents is therefore likely to be particularly effective in prevention of stroke
BACKGROUND AND PURPOSE Recent studies have shown that visit-to-visit blood pressure variability is a powerful risk factor for stroke , is reduced by calcium channel blockers and diuretics , and increased by β-blockers .
However , it is unknown whether these effects are dose-dependent and persist in combination with other drugs .