RESUMO
OBJECTIVES: To study the effect of Zingiber officinale and Hibiscus sabdariffa on pharmacokinetics and pharmacodynamics of amlodipine. METHODS: Hypertension was induced in rats (SBP 173.2 ± 1.7 mmHg, mean, 1-24 h). Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP) and heart rate (HR) of group-I (amlodipine treated), group-II (Z. officinale, and Z. officinale + amlodipine) and group-III (H. sabdariffa, and H. sabdariffa + amlodipine) animals were measured by "tail-cuff system". Pharmacokinetics of amlodipine with and without herbs (Z. officinale or H. sabdariffa) was also investigated. RESULTS: Z. officinale as well as H. sabdariffa decreased the SBP, DBP and MBP. Concurrent treatment with Z. officinale + amlodipine (SBP 129.4 ± 4.5) or H. sabdariffa + amlodipine (SBP 130.4 ± 3.9) showed higher decrease in BP (mean, 1-24h), than individually administered amlodipine (SBP 149.5 ± 2.4) or Z. officinale (SBP 150.2 ± 3.1) or H. sabdariffa (SBP 139.1 ± 1.2). These herbs also influenced the Cmax, AUC0-t, and Tmax of amlodipine. H. sabdariffa increased AUC0-t of amlodipine from 81.8 ± 14.7 to 125.0 ± 10.6 (ng h/mL). CONCLUSION: Simultaneous administration of Z. officinale or H. sabdariffa with amlodipine, improves its pharmacodynamic response.