Hernández R H, Armas-Hernández M J, Chourio J A, Armas-Padilla M C, López L, Alvarez M, Pacheco B
Clinical Pharmacology Unit, Hypertension Clinic, School of Medicine. Universidad Centroccidental Lisandro Alvarado, Barquisimeto, Venezuela.
Blood Press Monit. 2001 Feb;6(1):47-57. doi: 10.1097/00126097-200102000-00008.
To compare the antihypertensive efficacy of amlodipine and nifedipine gastrointestinal therapeutic system (GITS) measured by office and ambulatory blood pressure monitoring (ABPM) during treatment and, after patients have missed two doses.
After a single blind run-in 4-week placebo period, 58 patients were randomly allocated to amlodipine (5mg/daily, n=30) or nifedipine GITS (30mg/daily; n=28) in a double-blind, double dummy fashion. Patients received active medication for 4 weeks. Then, to simulate failure of compliance, patients received two single blinded doses of placebo. Ambulatory blood pressure monitoring was carried out at the end of run-in placebo phase, the first day, the last day of active treatment and up to 72h after the last active dose.
Diastolic blood pressure was controlled in 61.9% patients on amlodipine and 52.9% on nifedipine GITS. Reductions in blood pressure were similar in both groups. ABPM showed significant reduction in blood pressure from the first day in the nifedipine GITS group, while amlodipine group had marginal effect. Peak reduction in systolic/diastolic blood pressure was 26/15mmHg at 5-6h after ingestion of amlodipine tablets. The trough reduction was 22/13mmHg; with a trough-to-peak ratio of 84.61% for systolic and 86.67% for diastolic blood pressure. Peak reduction in systolic/diastolic blood pressure with nifedipine GITS was 19/15mmHg and the trough reduction was 21/17mmHg, giving a trough-to-peak ratio of 100% for both systolic and diastolic blood pressure. When patients received placebo after 4 weeks of active treatment, simulating a compliance failure, amlodipine maintained reduction in systolic and diastolic blood pressure for at least up to 72h after the last active dose, maintaining 57.71% of the effect for systolic blood pressure and 60.00% for diastolic blood pressure. In contrast, nifedipine GITS effect was rapidly lost during this study phase, with a reduction in systolic and diastolic blood pressure of only 14-16%, 72h after the last active dose.
This study showed that amlodipine and nifedipine GITS reduce blood pressure to about the same extent during chronic treatment. In the case of compliance failure, such as missing one or two doses, amlodipine maintained significant and important antihypertensive effect with the trough-to-peak ratio still over 50% 72h after the last active dose. On the other hand, the coverage of nifedipine GITS was limited to about 36h after the last active dose.
比较氨氯地平和硝苯地平胃肠道治疗系统（GITS）在治疗期间以及患者漏服两剂药物后通过诊室血压监测和动态血压监测（ABPM）所测得的降压疗效。
在为期4周的单盲导入安慰剂期后，58例患者以双盲、双模拟方式随机分配至氨氯地平组（5mg/每日，n = 30）或硝苯地平GITS组（30mg/每日；n = 28）。患者接受活性药物治疗4周。然后，为模拟依从性失败，患者接受两剂单盲安慰剂。在导入安慰剂期末、活性治疗的第一天、最后一天以及最后一剂活性药物后长达72小时进行动态血压监测。
氨氯地平组61.9%的患者舒张压得到控制，硝苯地平GITS组为52.9%。两组血压降低幅度相似。ABPM显示硝苯地平GITS组从第一天起血压显著降低，而氨氯地平组仅有轻微效果。氨氯地平片摄入后5 - 6小时收缩压/舒张压的最大降幅为26/15mmHg。谷值降幅为22/13mmHg；收缩压的谷峰比为84.61%，舒张压为86.67%。硝苯地平GITS的收缩压/舒张压最大降幅为19/15mmHg，谷值降幅为21/17mmHg，收缩压和舒张压的谷峰比均为100%。当患者在4周活性治疗后接受安慰剂，模拟依从性失败时，氨氯地平在最后一剂活性药物后至少72小时内维持收缩压和舒张压的降低，收缩压维持了57.71%的疗效，舒张压维持了60.00%的疗效。相比之下，在本研究阶段硝苯地平GITS的效果迅速丧失，最后一剂活性药物后72小时收缩压和舒张压仅降低14 - 16%。
本研究表明，氨氯地平和硝苯地平GITS在长期治疗期间降低血压的程度大致相同。在依从性失败的情况下，如漏服一剂或两剂，氨氯地平在最后一剂活性药物后72小时仍维持显著且重要的降压效果，谷峰比仍超过50%。另一方面，硝苯地平GITS的作用持续时间在最后一剂活性药物后约为36小时。
