Pentikäinen P J, Neuvonen P J, Penttilä A
Eur J Clin Pharmacol. 1979 Sep;16(3):195-202. doi: 10.1007/BF00562061.
The kinetics of 14C-metformin have been studied in five healthy subjects after oral and intravenous administration. The intravenous dose was distributed to a small central compartment of 9.9 +/- 1.61 (X +/- SE), from which its elimination could be described using three-compartment open model. The elimination half-life from plasma was 1.7 +/- 0.1 h. Urinary excretion data revealed a quantitatively minor terminal elimination phase with a half-life of 8.9 +/- 0.7 h. After the intravenous dose, metformin was completely excreted unchanged in urine with a renal clearance of 454 +/- 47 ml/min. Metformin was not bound to plasma proteins. The concentration of metformin in saliva was considerably lower than in plasma and declined more slowly. The bioavailability of metformin tablets averaged 50--60%. The rate of absorption was slower than that of elimination, which resulted in a plasma concentration profile of "flip-flop" type for oral metformin.
在五名健康受试者口服和静脉注射后，对14C-二甲双胍的动力学进行了研究。静脉注射剂量分布到一个9.9±1.61（X±SE）的小中央室，从该中央室可以使用三室开放模型描述其消除过程。血浆消除半衰期为1.7±0.1小时。尿排泄数据显示，存在一个半衰期为8.9±0.7小时的数量上较小的终末消除相。静脉注射剂量后，二甲双胍以原形完全经尿液排泄，肾清除率为454±47 ml/min。二甲双胍不与血浆蛋白结合。唾液中二甲双胍的浓度明显低于血浆，且下降更缓慢。二甲双胍片的生物利用度平均为50%-60%。吸收速率比消除速率慢，这导致口服二甲双胍的血浆浓度曲线呈“翻转”型。
