Christensen H R, Antonsen K, Simonsen K, Lindekaer A, Bonde J, Angelo H R, Kampmann J P
Department of Clinical Biochemistry, Bispebjerg University Hospital Copenhagen, Denmark.
Pharmacol Toxicol. 2000 Apr;86(4):178-82. doi: 10.1034/j.1600-0773.2000.d01-32.x.
Isradipine is a calcium channel-blocking agent of the dihydropyridine type, used in the treatment of hypertension. A terminal half-life of 8-9 hr has been reported, in several pharmacokinetic studies after oral administration of isradipine. In a yet unpublished study a much shorter half-life was observed, and the present trial was therefore conducted in order to estimate the half-life after intravenous administration of isradipine. The bioavailability was estimated as well. In a randomised cross-over design ten healthy young volunteers were given either isradipine orally or an intravenous infusion. The two study periods were separated by at least 3 days. Blood samples for measurement of isradipine concentration were collected for 10-12 hr after administration and half-life and bioavailability were estimated. Mean terminal half-life after intravenous administration was calculated to be 2.8 hr, and the bioavailability to be 0.28. None of the 10 subjects suffered from side effects. In the present intravenous study the half-life of isradipine seems to be of much shorter than demonstrated in previous oral studies.
伊拉地平是一种二氢吡啶类钙通道阻滞剂，用于治疗高血压。在几项口服伊拉地平后的药代动力学研究中，报告的终末半衰期为8 - 9小时。在一项尚未发表的研究中观察到半衰期要短得多，因此进行了本试验，以估计静脉注射伊拉地平后的半衰期。同时也对生物利用度进行了估计。采用随机交叉设计，10名健康年轻志愿者分别口服伊拉地平或静脉输注。两个研究期之间至少间隔3天。给药后10 - 12小时采集血样测定伊拉地平浓度，并估计半衰期和生物利用度。静脉给药后的平均终末半衰期计算为2.8小时，生物利用度为0.28。10名受试者均未出现副作用。在本次静脉研究中，伊拉地平的半衰期似乎比以往口服研究中显示的要短得多。
