Phillips T A, Howell A, Grieve R J, Welling P G
J Pharm Sci. 1980 Dec;69(12):1428-31. doi: 10.1002/jps.2600691220.
The pharmacokinetics of fluorouracil were examined after single 250-mg iv doses and 500-mg oral doses to female patients with breast cancer. In five patients who received intravenous fluorouracil, the mean peak plasma level of unchanged drug was 13.4 microgram/ml, the elimination half-life was 6.3 min, and the plasma clearance was 1410 ml/min. The last value is similar to the hepatic blood flow. In six patients who received oral fluorouracil, the mean peak value of unchanged drug in plasma, which occurred within 20 min of dosing, was 8.3 microgram/ml, and the fluorouracil elimination half-life was 7.2 min. The overall bioavailability of oral fluorouracil as unchanged drug was 28%, and the variation in plasma drug levels between individuals was similar following oral and intravenous doses. The data provide additional evidence of saturable hepatic metabolism of fluorouracil during the first pass.
对乳腺癌女性患者单次静脉注射250毫克和口服500毫克氟尿嘧啶后的药代动力学进行了研究。在接受静脉注射氟尿嘧啶的5名患者中，未变化药物的平均血浆峰值水平为13.4微克/毫升，消除半衰期为6.3分钟，血浆清除率为1410毫升/分钟。最后一个数值与肝血流量相似。在接受口服氟尿嘧啶的6名患者中，给药后20分钟内血浆中未变化药物的平均峰值为8.3微克/毫升，氟尿嘧啶消除半衰期为7.2分钟。口服氟尿嘧啶作为未变化药物的总体生物利用度为28%，口服和静脉给药后个体间血浆药物水平的差异相似。这些数据为氟尿嘧啶在首过过程中肝脏代谢饱和提供了更多证据。
