Ndanusa B U, Mustapha A, Abdu-Aguye I
Department of Pharmaceutical and Medicinal Chemistry, Ahmadu Bello University, Zaria, Nigeria.
J Pharm Biomed Anal. 1997 Jun;15(9-10):1571-5. doi: 10.1016/s0731-7085(97)00044-7.
The pharmacokinetic interaction of oral rifampicin (1200 mg) and oral nifedipine (10 mg capsules), given as single doses, was investigated in six healthy volunteers (mean age 28.5 +/- 6.3 years and mean weight 67.0 +/- 4/45 kg). The plasma concentrations of nifedipine was monitored using a HPLC technique, 8 h after pre-treatment, with rifampicin. The mean relative bioavailability of nifedipine following pre-treatment with rifampicin 1200 mg was 35.8% (P < 0.0001). The mean elimination half life (t1/2) of nifedipine decreased from 2.62 to 1.03 h (P < 0.0001); and, the total clearance (ClT) increased from 17.33 to 50.17 ml min-1 kg-1 (P < 0.0001). There were no significant differences in Vd and Tmax. The study suggests that the effect of induction by rifampicin decreases the bioavailability of nifedipine by either increasing the first pass effect or decreasing its oral absorption. The induction also increases the clearance of nifedipine.
在6名健康志愿者（平均年龄28.5±6.3岁，平均体重67.0±4.45kg）中研究了单剂量口服利福平（1200mg）与口服硝苯地平（10mg胶囊）的药代动力学相互作用。在使用利福平预处理8小时后，采用高效液相色谱技术监测硝苯地平的血浆浓度。1200mg利福平预处理后硝苯地平的平均相对生物利用度为35.8%（P<0.0001）。硝苯地平的平均消除半衰期（t1/2）从2.62小时降至1.03小时（P<0.0001）；总清除率（ClT）从17.33增加至50.17ml·min-1·kg-1（P<0.0001）。分布容积（Vd）和达峰时间（Tmax）无显著差异。该研究表明，利福平的诱导作用通过增加首过效应或减少其口服吸收来降低硝苯地平的生物利用度。这种诱导作用还增加了硝苯地平的清除率。
