药动学习题是.doc

PAGE  PAGE 6 药 物 动 力 学 习 题 Following the intravenous administration of 250mg of Phenytoin to 12 human subjects, the mean plasma concentration versus time data presented below was obtained: t (h) :248122448C (?g/ml):5.044.684.003.462.210.90 Plot these data and estimate the apparent volume of distribution (V) and the overall elimination rate constant (k) for Phenytoin. Determine the biologic half-life . Consider the following data obtained after IV administration of 250mg of a penicillin derivative. Calculate t1/2 , k, V, CL. t (h) :0.250.51.01.52.02.53.0C(?g/ml):6.854.892.451.20.600.300.15 100mg of a drug is injected intravenously into a human subject. The drug rapidly distributes into a human subject. 8 hours after the injection the plasma level of the drug is 2.8?g/ml. 16 hours after injection the plasma level of drug is 1.4?g/ml. Calculate: 1) biological half-life of the drug 2) elimination rate constant 3) volume of distribution 4) plasma clearance For the patient below it is desired to achieve an initial plasma concentration of the antibiotic of 60?g/ml, What dose should be used? (X0iv=250mg) t (h) :0.51.02.04.08.012.024.0C(?g/ml):39.336.030.021.711.15.620.74 A drug is administration to a 70kg patient by means of a constant rate iv infusion at a rate of a 0.5mg/min. The drug has a biological half-life of 4.5 hours , appears to distribute into a volume of 3L. Calculate the steady state plasma levels achieved with the infusion. Calculate the time taken to reach 95% and 99% of the steady state level. 6、给1个50kg体重的患者静脉注射某抗生素6mg/kg，测得不同时间的血药浓度如下： t(h)0.250.51.03.06.012.018.0C(?g/ml)8.227.887.265.163.081.120.40求：(1)消除速率常数，表观分布容积，半衰期，消除率。 (2)描述上述血药浓度的方程。 (3)静脉注射后10h的