Schwieler J H, Ericsson H, Löfdahl P, Thulin T, Kahan T
Division of Internal Medicine, Karolinska Institutet, Danderyd Hospital, Sweden.
J Cardiovasc Pharmacol. 1999 Aug;34(2):268-74. doi: 10.1097/00005344-199908000-00013.
The pharmacokinetics of clevidipine, a potent short-acting vascular-selective calcium antagonist, was investigated during steady state and the postinfusion period in patients with mild to moderate hypertension. Furthermore, the dose-effect and blood concentration-effect relations and the tolerability of the drug were studied. Twenty patients were randomized to clevidipine intravenously at target dose rates of 0.18, 0.91, 2.74, and 5.48 microg/kg/min, respectively, or placebo. Each patient received in random order three infusion rates of clevidipine or placebo during three separate study days. Dose-dependent reduction in blood pressure and a modest increase in heart rate were noted. The extremely high clearance value and the small volume of distribution resulted in short half-lives of clevidipine, 2.2 and 16.8 min, respectively. The blood concentration and dose rate producing half the maximal effect (i.e. EC50 and ED50) were approximately 25 nM and 1.5 microg/kg/min, respectively. There was a linear relation between blood concentration and dose rate in the range studied. Clevidipine was safe and generally well tolerated; one patient was excluded because of adverse events at 2.74 microg/kg/min. In conclusion, clevidipine is a high-clearance calcium antagonist that may become a valuable contribution to the drugs used in conditions in which precise and rapid control of blood pressure is needed.
在轻度至中度高血压患者的稳态期和输注后阶段,对强效短效血管选择性钙拮抗剂氯维地平的药代动力学进行了研究。此外,还研究了该药的剂量效应和血药浓度效应关系以及耐受性。20例患者分别以0.18、0.91、2.74和5.48微克/千克/分钟的目标剂量率随机接受静脉注射氯维地平或安慰剂。每位患者在三个独立的研究日中随机接受三种氯维地平输注速率或安慰剂。观察到血压呈剂量依赖性降低,心率略有增加。极高的清除率值和较小的分布容积导致氯维地平的半衰期较短,分别为2.2分钟和16.8分钟。产生最大效应一半时的血药浓度和剂量率(即EC50和ED50)分别约为25纳摩尔和1.5微克/千克/分钟。在所研究的范围内,血药浓度与剂量率之间呈线性关系。氯维地平安全且耐受性一般良好;一名患者因在2.74微克/千克/分钟时出现不良事件而被排除。总之,氯维地平是一种高清除率的钙拮抗剂,对于需要精确快速控制血压的疾病所使用的药物可能会有重要贡献。