老年患者口服法莫替丁的药物动力学

Pharmacokinetics of famotidine in elderly patients

健康志愿者１０例和老年消化性溃疡患者６例单剂量口服４０ｍｇ法莫替丁（Ｆａｍ）后，体内处置符合一室开放模型，老年患者Ｔ１／２为０．５９±１．８１ｈ，药－时曲线下面积８６６．５±１９４ｎｇ·ｍｌ－１·ｈ－１，肾清除率和总清除率分别为３２９±４５．５ｍｌ／ｍｉｎ和４３８±３４ｍｌ／ｍｉｎ，２４ｈＦａｍ原型经肾排出量为总剂量的２１．５％，与健康志愿者相比，消除明显减慢，血药浓度水平升高，临床使用时需调整剂量，避免由于药物在体内蓄积而引起的不良反应。

The pharmacokinetics of famotidine (Fam) were studied after the administration of a single oral dose of 40 mg to ten young healthy volunteers and six elderly patients with peptic ulcer. In elderly patients, the plasma elimination half-life was 6.59±1.81h. The area under plasma concentration-time curve was 866.5±194 ng. mg-1. h-1. Mean renal and total body clearance were 329±45.5 ml/min and 438±34 ml/min. About 21. 5% of the dose were recovered as unchanged Fam in urine within 24 h. Significant differences were oberved in most pharmacokinetic parameters between healthy volunteers and elderly patients. Thus reduction in drug dosage should therefore be necessary in elderly patients.