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Once-daily antihypertensive treatment with calcium antagonists: utopia or reality?
J A Staessen1, H Celis, L Thijs
1Department of Molecular and Cardiovascular Research, University of Leuven, Belgium.
Insights
Evaluating antihypertensive drug efficacy requires standardized 24-hour blood pressure control evidence. This review highlights issues in studies assessing calcium antagonists, emphasizing the need for robust data on sustained blood pressure reduction.
Area of Science:
- Pharmacology
- Cardiovascular Medicine
- Clinical Trials
Background:
- Many antihypertensive drugs are approved for once or twice daily dosing.
- No standardized evidence is required to prove 24-hour blood pressure control.
- Calcium antagonists are a common class of antihypertensive medications.
Purpose of the Study:
- To review the literature on calcium antagonists to identify arguments for a long duration of action.
- To assess the quality of evidence supporting the 24-hour efficacy of these drugs.
- To highlight methodological limitations in existing studies.
Main Methods:
- Literature search of studies on calcium antagonists.
- Focus on studies using ambulatory blood pressure monitoring.
- Analysis of methodological quality and data interpretation.
Main Results:
- Several calcium antagonists (amlodipine, diltiazem SR, felodipine SR, isradipine SR, nifedipine SR, nitrendipine, verapamil SR) are reported to reduce 24-hour blood pressure.
- Many studies had interpretational issues including non-blinded designs, inappropriate statistics, and lack of baseline adjustment.
- Some studies provided detailed diurnal blood pressure profiles and end-of-dosing interval data.
Conclusions:
- Robust evidence for sustained 24-hour blood pressure reduction in antihypertensive drug studies is often lacking.
- Methodological rigor is crucial for accurately assessing the duration of action of antihypertensive medications.
- Standardized criteria are needed to evaluate the 24-hour efficacy of antihypertensive drugs.
Abstract:
Although a large number of antihypertensive drugs have been approved for once- or twice-daily dosing, no standardized set of evidence is required to demonstrate that the blood pressure reduction is sustained for 24 h. The recent literature on calcium antagonists was therefore searched for the arguments usually put forward to objectify a long duration of action. Most studies relied on ambulatory blood pressure monitoring. However, several published reports were difficult to interpret for a variety of reasons, such as: (1) a non-blinded non-randomized study design; (2) a statistical analysis, which was discordant with the study design; (3) analyses confined to the 24 h, day-time and night-time pressure means; (4) the absence of a baseline adjustment and/or formal statistical testing; (5) the "post hoc" subdivision of patients into responders and non-responders; and (6) the absence of a well-specified time-frame linking drug intake to the observed antihypertensive effects. According to the authors' interpretation, amlodipine, diltiazem SR (modified release), felodipine SR, isradipine SR, nifedipine SR, nitrendipine and verapamil SR have all been confirmed to reduce both the conventional and the 24 h blood pressure. Some studies went beyond the 24 h blood pressure means and also presented separate results for the day-time (or awake) and night-time (or sleeping) periods, or investigated the blood pressure reduction at the end of the dosing interval, or compared the diurnal blood pressure profiles on different treatments.(ABSTRACT TRUNCATED AT 250 WORDS)