Desager J P, Dab I, Horsmans Y, Harvengt C
Department of Internal Medicine, Université Catholique de Louvain, Belgium.
Clin Pharmacol Ther. 1993 Apr;53(4):431-5. doi: 10.1038/clpt.1993.47.
The pharmacokinetics of the second-generation H1-receptor antagonist cetirizine was studied in eight children younger than 4 years of age who were treated with a single dose of cetirizine solution (5 mg). These children were hospitalized with suspected allergic respiratory problems or recurrent respiratory tract infections. Blood samples were collected at 1/2, 1, 1 1/2, 2, 4, 6, 8, 12, and 24 hours, and a 24-hour urine collection was performed in five of the samples. The findings obtained in children were compared with those obtained in 16 healthy young adults (mean +/- SD, 24.6 +/- 4.1 years) who received a single 20 mg dose. Cetirizine was absorbed more slowly in children (p = 0.006; mean +/- SD, 1.44 +/- 1.12 hours) than in adults (0.62 +/- 0.22 hours). The plasma elimination half-life of cetirizine was significantly shorter in children (p < 0.001; 4.91 +/- 0.6 hours) than in adults (8.6 +/- 2.1 hours), and the clearance rate was significantly higher in children (p < 0.001; 1.48 +/- 0.41 ml/min/kg) than in adults (0.80 +/- 0.17 ml/min/kg). Urinary excretion of unchanged cetirizine was significantly lower in children (p < 0.001; 37.8% +/- 5.2%; n = 5) than in adults (57.7% +/- 11.8%). Therefore the metabolism of cetirizine is faster in young children than in adults. This effect must be taken into account in future pharmacodynamic studies in this age group.
在8名4岁以下因疑似过敏性呼吸道问题或反复呼吸道感染而住院的儿童中，研究了第二代H1受体拮抗剂西替利嗪的药代动力学。这些儿童接受了单剂量西替利嗪溶液（5毫克）治疗。在给药后1/2、1、1 1/2、2、4、6、8、12和24小时采集血样，并对其中5份样本进行了24小时尿液收集。将儿童的研究结果与16名接受单剂量20毫克西替利嗪的健康年轻成年人（平均±标准差，24.6±4.1岁）的结果进行比较。西替利嗪在儿童体内的吸收比成人更慢（p = 0.006；平均±标准差，1.44±1.12小时对比0.62±0.22小时）。西替利嗪的血浆消除半衰期在儿童中显著短于成人（p < 0.001；4.91±0.6小时对比8.6±2.1小时），清除率在儿童中显著高于成人（p < 0.001；1.48±0.41毫升/分钟/千克对比0.80±0.17毫升/分钟/千克）。儿童中未变化的西替利嗪尿排泄显著低于成人（p < 0.001；37.8%±5.2%；n = 5对比57.7%±11.8%）。因此，西替利嗪在幼儿中的代谢比成人更快。在该年龄组未来的药效学研究中必须考虑到这一效应。
