药理学总论英文(睢大员).pptVIP

Absorption distribution excretion Cell membrane 1) GI epithelial cells 2) vascular endothelium 3) blood brain barrier (BBB) 4) subcellular membranes ANY QUESTIONS？ THANK YOU！ 4. Excretion excretion of kidneys excretion of bile excretion of mammary gland Hepatoenteral circulation liver--bile gall bladder duodenum excrete 4. Excretion 消除 transport and transformation of drugs Section 2 Basic concept of pharmacokinetics A. Time-concentration curve threshold dose Cmax Tpeak TCmin B. Half Life (t1/2) first order kinetics t1/2 = 0.693/K zero order kinetics t1/2 = 0.5C/K C. Compartment model absoption elimination Drug one-compartment model two-compartment model drug central compartment peripheral compartment absoption elimination D. Clearance (CL) CL = Vd . K or 0.693.Vd/t1/2 0 2 1 0 1 2 3 4 5 6 Steady state con Css.max Css.min 7 E. Steady state concentration (Css) 血药浓度 100 200 300 8 0 2 4 6 0 0 0 2 4 6 8 100 200 300 时间（半衰期） 100 200 300 0 2 4 6 0 A B C 8 MTC MEC 三种不同给药方案对稳态浓度的影响 A. 缩短给药时间 B. 增加给药剂量 C. 负荷量给药 F. Drug elimination rate dc/dt = -KCn C: concentration of the drug K: elimination rate constant n=1 first order kinetics -dc/dt = KC1 n=0 zero order kinetics -dc/dt = KC0 = Vmax First order kinetics: constant fraction of drug is eliminated per unit time Zero order kinetics : same quantity of drug is eliminated per unit time Dose Response Curve Emax Emax Chapter 2 Pharmacodynamics LD50 therapeutic index (TI) = ───── ED50 LD5 safety index (SI) = ───── ED95 (LD1 - ED99) safety margin (SM) = ───