Trough:peak ratio of the blood pressure response to dihydropyridine calcium antagonists. Italian Nifedipine GITS Study Group.

OLD VERSUS NEWER DIHYDROPYRIDINE CALCIUM ANTAGONISTS

First-generation dihydropyridines have a short duration of antihypertensive action, which requires more than one daily dose in order to produce a relatively 'smooth' antihypertensive effect. However, more recent molecules or preparations have been shown to possess a much longer and smoother action. TROUGH:PEAK RATIOS OF NIFEDIPINE GASTROINTESTINAL THERAPEUTIC SYSTEM (GITS): The Italian Nifedipine GITS Study has shown, by using ambulatory blood pressure monitoring for 24-36 h, that nifedipine GITS, a new slow-release preparation, is capable of producing a marked reduction in both systolic and diastolic blood pressure that extends to 30-36 h after the dose. In this study, nifedipine GITS produced a smooth antihypertensive effect throughout the dose interval of 24 h by whatever method was used to evaluate this effect: (1) hourly blood pressure profiles; (2) trough:peak ratios, corrected or uncorrected by placebo effects (ratios often approached 100%); (3) calculation of individual trough:peak ratios in all treated patients (60% of whom had ratios of > 50%); and (4) calculation of individual trough:peak ratios in 'responders' to nifedipine GITS (approximately 75% of whom had ratios of > 50%). USE OF AMBULATORY BLOOD PRESSURE MONITORING: The large body of data on ambulatory blood pressure monitoring provided by this study has also allowed comparison and analysis of the advantages and disadvantages of the various methods of assessing the smoothness of the antihypertensive action of a drug by ambulatory blood pressure monitoring.