1、kXdtdX X0Xk公式推导:公式推导: :体内药物的消除速度:体内药物的消除速度 k:一级消除速度常数:一级消除速度常数 负号:体内药量负号:体内药量X随随t的推移不断减少的推移不断减少dtdXt.k3032303. 2kTime (h)0.100.05Time (h)log0.100.01斜率斜率-303. 2k截距截距lgCot303. 2kt303. 2kCClgt693. 0303. 2CClgk303. 2t02/10 0kt0dteC 0ktdtekVX0XkdtdXeu dtdXudtdXut303. 2kdtdXu303. 2kdtdXudtdXuXkdtdXeu kXk0
2、ekt0eekXk t303. 2kkXk0et303. 2k)e1(kXkkt0e kkXXe0u kke frh990706930693021.k.t/ -101h0042. 01000179. 46211. 0lg Xkemg 59.7)1(07. 02 . 4)1(8007. 00 eekXkXkteuk0XkkXkdtdX0 dX/dt:体内药物量的瞬时变化率,:体内药物量的瞬时变化率,k0:静脉滴注速度常数(单位时间药量):静脉滴注速度常数(单位时间药量)k:消除速度常数。:消除速度常数。)e1(kkkto )e1(kVkkto kVk)e1(kVk0kt0 kte1 nnttkt
3、693. 0693. 02/12/1nsssseCCf693. 01nssef693. 01303. 2693. 0)lg()1lg(693. 0nefnss)1lg(32. 3ssfnfss = C/Css=kte152.23 mg/Lkt0eC kt0ekVk )e1(kVkCCktot0 kt0eCC )e1(kVkkto )e1(10231. 0308231. 0 )e1(kkeXXktokt0 )e1(kkeXXktokt0 为为静静注注和和静静滴滴血血浓浓的的和和k = 0.693/t1/2= 0.693/40 = 0.0173 h-1静静注注的的血血浓:浓:C1 = = e-0.
4、01734= 0.373 mg/L静静滴滴的的血血浓:浓:C2= = (1- e-0.01734) = 1.546 mg/LC= C1 + C2= 0.373 + 1.546 = 1.919 mg/Lktd0eVX )e1(kVkktd0 60021.010 aaaXkdtdX XkakXaX0FkXXkdtdXaa )ee (kkFXktkkta0aa )ee ()kk(VFXktkkta0aa )kk(VFXka0a )ee (Atkkta )ee ()kk(VFXktkkta0aa )07. 08 . 0(102007 . 08 . 0 )07. 08 . 0(102007 . 08 .
5、 0 )07. 08 . 0(102007 . 08 . 0 时时 间间 血浆药物浓度血浆药物浓度 (mg/L) 静脉注射静脉注射 口口 服服 TmaxCmaxPlasma concentrationCmax tmax吸吸收收项项消除项消除项kVFXAUC0)(tkktaeeAtk303. 2tka303. 2)(0kkVFXkaa外推外推线线残数线残数线图图 单室模型血管外给药的血药浓度、残数浓度曲线图单室模型血管外给药的血药浓度、残数浓度曲线图)kk(VFXkad0a 000()()()()aak tktktaataak taak FXk FXCCeeeV kkV kkk FXeV kk
6、0lglg2.303()aarakk FXCtV kk CrlnC = 4.215 - 0.0683t前提条件前提条件kak,一般一般ka5k末端末端35点数据,点数据,lnCtt回归回归得得k外推外推lnCtt直线求外推浓度直线求外推浓度Ct求残数浓度求残数浓度Cr=Ct ClnCrt回归得回归得kaCt数据点一般不少于数据点一般不少于10个个取样时间要足够大,取样时间要足够大,5 t1/2n Wagner-Nelson法法求求kaEAXXX kVCdtdCVdtdXA dtdXdtdXdtdXEA kXdtdXdtdXA tAt0A0( X)( X)tCkCdtkCdt 0()tA ttX
7、VCkVCdt 0CdtkV)X(A0000(1)ak tttFXeCkCdtVFXkCdtV ()1()ak tAtAXeX ()lg1001lg100()2.303A taAXktX ()1()ak tAtAXeX A000A()d ,d ,d ,()ttttXC t kC t CtkC tX000()()()aaak FXk ttk ttCeeV kk t0一、血药浓度法图解法图解法参数计算法参数计算法Ct中中ktkkkkFXlntXlnaeau 0kak, t 较大时较大时:一般只能求得一般只能求得k值,值,ka较难求得较难求得X0FkaknekeXuXaX)ee (kkkkFXXkd
8、tdXt kktaeaeua 0uXtt中中ekekkkXXXkkekekXX)kk(kekkkek(kkkFXXtkktaauuuatkktauuaatkaktaeauaaa 10kak, t 较大时:较大时:ktkkkXln)XXln(ekkkXXXaauuuktaauuu Xu =FX0ke/k1某患者单次静脉注射某单室模型某患者单次静脉注射某单室模型药物药物2g,测得不同时间的血药浓度结,测得不同时间的血药浓度结果如下:果如下:求求k,Cl,T1/2,C0,V,AUC和和14h的血药浓的血药浓度。度。 y = -0.022x + 0.2809R2 = 0.96224954. 0061.
9、 0logtCkteCC0tkCC303. 2loglog0得回归方程:1h1405. 0)061. 0(303. 2303. 2bkh9323. 41405. 0693. 0693. 02/1kTmg/ml3196. 0)4954. 0(log10C6.258Lml)(62583196. 0200000CXVL/h8792. 0258. 61405. 0 kVCl)(mg/mlh2747. 21405. 03196. 0AUC00kC3495. 14954. 014061. 0logCg/ml44.7mg/ml)(0477. 0C图解法求:图解法求:k,ka,Tmax,Cmax,V,AUC,
10、Cl(已知(已知F=0.698) )()(0katktaaeekkVFXkCktAeCtkAC303.2loglog)h(0957. 0)0416. 0(303. 21k)h(788. 0)3422. 0(303. 21akv从截距可知A=82g/ml)9.689(L9689(ml)82)0957. 0788. 0(1000000698. 0788. 0)(0AkkFXkVaa分布容积表观)log(log303. 2maxkkkkTaa达峰时)h(046. 3)0957. 0log788. 0(log0957. 0788. 0303. 2max0maxKTeVFXC峰浓度)g/ml(82.53
11、96891000000698. 0046. 30957. 0eh)g/ml(77.7520957. 096891000000698. 0AUC0VkFX曲线下面积总清除率总清除率inkVCl15.45ml/mml/h)(24.9270957. 096891h0957. 0k1h788. 0akV = 9.689L,Tmax = 3.046h, C max = 53.82 g/ml,h)g/ml(77.752AUCCl = 15.45ml/min(0.5)0.0126(0.5)0.0126100.01260.0126020.01260.0126120.01260.01260.1670.16510(1)(1)13.2 13.20.0126 600.16513.2 13.20.50.16513.2 13.22.k tttktttttttCCeeekCeeekVCCCeeeet 03 h