Kivistö K T, Neuvonen P J, Tarssanen L
Department of Clinical Pharmacology, University of Helsinki, Finland.
Hum Exp Toxicol. 1997 Jan;16(1):35-7. doi: 10.1177/0960327197016001071.
The information on the pharmacokinetics of verapamil in overdose is scanty. We report two adults who ingested 3.2 g and 4 g of verapamil, respectively. Both patients had hypotension and a severe bradycardia. The highest plasma verapamil concentration in these patients was about 2200 ng/ml and 2700 ng/ml, respectively. The decline in plasma verapamil and norverapamil concentrations followed first-order kinetics, and the half-life of verapamil was 7.8 h and 15.1 h, respectively. The free fraction of verapamil (non-protein bound) was higher at total concentrations exceeding 2000 ng/ml (12-15%) than at lower concentrations (2-6%). There seems to be no marked saturation of the metabolism of verapamil in acute poisoning. The apparent concentration-dependent changes in the free fraction may be due to therapeutic measures.
关于过量服用维拉帕米的药代动力学信息很少。我们报告了两名分别摄入3.2克和4克维拉帕米的成年人。两名患者均出现低血压和严重心动过缓。这些患者血浆中维拉帕米的最高浓度分别约为2200纳克/毫升和2700纳克/毫升。血浆中维拉帕米和去甲维拉帕米浓度的下降遵循一级动力学，维拉帕米的半衰期分别为7.8小时和15.1小时。当总浓度超过2000纳克/毫升时，维拉帕米的游离分数（非蛋白结合部分）（12 - 15%）高于较低浓度时（2 - 6%）。急性中毒时维拉帕米的代谢似乎没有明显的饱和现象。游离分数中明显的浓度依赖性变化可能归因于治疗措施。
