非线性混合效应模型法在群体药代动力学和群体药效学中的研究进展

群体药代动力学和群体药效学是近年来得到快速发展的药学领域，具有广阔的应用前景。本文对群体药代动力学和群体药效学重要估算方法非线性混合效应模型法进行综述，包括基本概念、常用模型、模型确定方法、数值计算和应用等方面。     

应用非线性混合效应模型法考察儿童疾病因素对环孢素药动学的影响

目的:考察疾病因素对于环孢素A(CsA)在儿童体内药动学的影响,促进个体化用药。方法:收集150例包括再生障碍性贫血(AA)、嗜血细胞综合征(HPS)和难治性肾病综合征(RNS)不同病种患儿的CsA血药浓度数据和临床资料。采用非线性混合效应模型法考察疾病种类因素对于CsA药动学的影响。采用Bayesian最大后验概率法获取并比较CsA在不同病种患者中药动学参数的差异。用拟合优度(goodness-of-fit)、自举法(bootstrap)、直观预测检验法(VPC)、正态化预测分布误差(NPDE)对最终模型的预测性能进行验证。结果:最终模型药动学参数的群体典型值分别为:吸收速率常数(k_a)1.22 h^-1,吸收时滞时间(T_lag)0.45 h,表观分布容积(V_d)218.18 L,口服清除率(CL)14.45 L·h^-1。拟合优度、自举验证、VPC和NPDE结果表明最终模型稳定,预测结果可靠。模型结构显示只有患者的体质量和AST值是影响CsA清除率的显著性因素。CsA在AA、HPS和RNS患者中的药动学参数差异无显著性(P>0.05)。结论:本研究成功获取了CsA在儿童AA、HPS和RNS患者中的药动学参数,上述疾病因素不会显著影响CsA在儿童体内的药动学过程。     

群体药代动力学及其在新药研究中的应用

近年来新药临床研究越来越重视群体药代动力学的应用。群体药代动力学可以定量地描述病理、生理、合并用药等多种因素对药物代谢的影响，可将PK参数中的各种变异区分开，指导用药方案的调整，从而增强对新药有效性和安全性的评价。本文对群体药代动力学的研究方法及其在新药研究中的应用进行综述．     

肾移植病人口服环孢素的药代动力学

本文用HPLC法测定环孢素的全血浓度,对8例异体肾移植病人口服环孢素后的药代动力学特性进行研究。病人在肾移植后用环孢素的时间为47天到11个月,平均给药剂量为8.26±1.41 mg/kg·d(5.88～10.0mg/kg·d),每12h一次。病人常规监测血样本300余次。测得病人的环孢素药代动力学参数:峰浓度(Cmax)664.9±87.5 ng/ml,达峰时间(Tmax)3.27±1.07h;t¹/₂β13.53h(6.13～44.3h)。     

非线性混合效应模型法估算肾移植患者环孢素A的相对清除率

目的:用非线性混合效应模型(NONMEM)法定量考察年龄、性别、体重、合并用药、肝功能、合并症和服药持续时间对清除率的影响.方法:收集中山大学附属第一医院由1999～2001年临床221例肾移植患者323人次肾移植后服用环孢素A(CsA)3 d以上谷值浓度,应用SAS程序估算其药动学参数(参考NONMEM程序一步法).结果:按口服吸收一室开放模型的群体药动学参数:清除率CL、表观分布容积Vd分别等于13.46 L·h-1,228.2 L,浓度观察值与模型预测值的残差变异σE(%)等于0.006 5.其个体间变异σCL(%)为5.94.CL(L·h-1)的最终回归方程为:CL=13.46-0.063 A 0.082 W.其中A为患者年龄;W为患者体重(kg).结论:年龄越大,CL越小;体重越大,CL越大.     

非线性混合效应模型估算环孢素在人体相对生物利用度和药动学参数

目的:用非线性混合效应模型(NONMEM)估算环孢素2种制剂在人体的相对生物利用度和药动学参数。方法: 20名男性志愿者随机、交叉单次口服环孢素微乳剂和普通乳剂500mg。HPLC法测定血药浓度。经典药动学方法和NONMEM法估算相对生物利用度和药动学参数。结果:用NONMEM法估算环孢素微乳剂生物利用度是普通乳剂的(209±s60) %;普通乳剂和微乳剂的V/F分别是(0. 30±0. 10), (0. 14±0. 06)L;Ka分别是0. 40±0. 11, 0. 9±0. 5;Ke分别是0. 16±0. 18, 0. 32±0. 13;K12分别是0. 23±0. 17, 0. 20±0. 17;K21分别是0. 021±0. 021, 0. 17±0. 08, 与传统方法相比基本一致。结论:NONMEM法为药物生物利用度评价和药动学参数计算提供一种简捷和快速的数据分析途径。     

群体药代动力学研究进展

群体药代动力学(PK)用统计学和动力学原理,对不同的人群定量计算其PK参数,并描述其个体间和个体内变异的特征以及来源。近年来其受到越来越多的重视,本文对群体PK的原理及应用进行了综述。     

建立阿奇霉素在中国健康人群中的群体药代动力学模型

目的建立中国人群中阿奇霉素(大环内酯类抗生素)的群体药代动力学模型。方法对20例健康自愿者的血药浓度和生化指标,用非线性混合效应模型法进行群体药代动力学分析,估算药代动力学参数,分析固定效应的影响以及个体内/间的变异,建立群体药代动力学模型。结果口服阿奇霉素呈一级吸收的二室模型,体质量对CL1和CL2及年龄对V1均有影响。结论用非线性混合效应模型法建立的中国人群中阿奇霉素的群体药代动力学模型,结构稳定,预测准确。     

MDR1基因多态性对口服环孢素A药代动力学的影响

目的非线性混合效应模型(NONMEM)考察中国健康人多药耐药基因(MDR1)中26外显子的C3435T多态性与环孢素A (CsA)药代动力学特性间的关系。方法HPLC法测定20名健康男性单次口服CsA微乳溶液制剂500 mg后24 h内不同时间点的药物浓度。MDR1的基因多态性测定采用DNA限制性片段长度多态性法，并用基因测序法验证。数据处理与模型拟合采用NONMEM法。结果中国健康人中含MDR1 C3435T CC或CT型的相对生物利用度较TT型高40%。结论MDR1中C3435T多态性是个体间CsA相对生物利用度差异的影响因素。     

非线性混合效应模型法的临床应用进展

非线性混合效应模型法广泛应用于临床各类药物的群体药动学参数估算.本文通过对国内外近十年来大量运用该法研究的论文进行归纳整理,介绍群体药代动力学研究中非线性混合效应模型法的临床应用进展.     

Application of NONMEM to routine bioavailability data

Although NONMEM has been proposed as a modeling tool for sparse data sets, little work has described its application to pharmacokinetic data which is also amenable to typical evaluations. An analysis was performed with NONMEM using plasma concentration data obtained during the development of liquid and capsule extended-release (ER) pseudoephedrine products. A total of four studies (single dose and steady-state studies for both the liquid and capsule formulations) were evaluated, each with an immediate-release (IR) control, and consisting of 18 to 20 subjects. NONMEM analyses provided additional information which could not be obtained through traditional means. Specifically, NONMEM provided not only estimates of residual error from single dose and steady-state studies but also a stochastic measure of bioinequivalence and dose-dumping. It permitted hypothesis testing in the same process as pharmacokinetic parameter estimation, such as contrasting absorption rates from capsule and suspension ER products. A less biased estimate of absorption rate was obtainable for E R formulations by utilizing IR runs. Finally, these NONMEM runs confirmed that, even when data are plentiful and amenable to two-stage analyses, NONMEM provides estimates that may in fact be more meaningful and less susceptible to assay or residual variability. Fundamental differences between population and two-stage approaches are discussed.Glossary NONMEM NONlinearMixed Effects Models Program - ER Extended release (formulation) - IR Immediate release (formulation) - Study SUSP-SD Single dose suspension bioavailability study - Study SUSP-SS Steady-state suspension bioavailability study - Study CAP-SD Single dose capsule bioavailability study - Study CAP-SS Steady-state capsule bioavailability study - D Dose,g - V Population average apparent volume of distribution, L/kg - Ke Population average terminal elimination rate constant, hr^–1 - Ka Population average absorption rate constant, hr^–1 - V _j,ke _j, andKa _j The jth individual's estimates ofV, Ke, andKa - _jV, _j ke, and _j Ka Randomly distributed interindividual (between-subject) errors with a mean of zero and variances estimated by NONMEM - CONC Predicted concentration, ng/ml - CONC _mij The ith predicted concentrations from pharmacokinetic(V, Ke, Ka) and statistical ( _j V, _j Ke, _j ^Ka ) model - CONC _ij The ith observed concentration from the jth individual - _ij Residual intrasubject (within-subject) error corresponding toCONC _ij, - CF _Ka ,CF _BIO Contrast fractions for capsule vs. suspension parameters corresponding toCONC _ij - KaREL Relative absorption rate expressed as a ratio ofKa for Formulation ER divided byKa for Formulation IR - Population (typical) parameter estimate from NONMEM - ₂ Interindividual () variance estimate from NONMEM (reported as %CV in Tables) - ₂ Intraindividual () variance estimate from NONMEM (reported as% CV in Tables) - SEE Standard error of the estimate - 95% CI 95% Confidence interval for, ², or ² - %CV Coefficient of variation, expressed as percent - t _i The ith sample time, associated withCONC _mij , andCONC _ij - Ka _IR Ka from formulation IR - Ka _ER Ka from one of the ER formulations - BIO Bioavailability of an ER formulation relative to Formulation IR - _jBIO, _j KaREL Ratio error terms whose variances can describe frequency distribution for bioinequivalence and dosedumping of ER formulations     

Effect of co-administration of Intralipid on the pharmacokinetics of cyclosporine in the rabbit

The effect of Intralipid co-administration on the pharmacokinetics of cyclosporine (CyA) was studied in NZW rabbits. A single intravenous bolus dose of CyA (10 mg kg-1) mixed with 3 ml of Intralipid was administered to rabbits (n = 4). Control animals (n = 4) received the same dose of CyA without Intralipid. Serial blood samples were collected up to 12 h after the administration of CyA. Concentrations of CyA in plasma were analyzed using a HPLC method. The terminal elimination half-life (t1/2) of CyA was significantly lower with Intralipid administration (191 +/- 25 min) than control (298 +/- 59 min). The total body clearance (ClTOT) and volume of distribution (Vdss) of CyA was reduced by approximately 65-70 per cent with Intralipid administration compared to control. The free fraction of CyA in plasma with and without Intralipid administration was estimated to be 0.05 +/- 0.01 and 0.17 +/- 0.06, respectively. Co-administration of Intralipid with CyA decreased both the ClTOT and Vdss resulting in a rapid elimination, i.e., decrease in a t1/2 of CyA from the body.     

甘草提取物对大鼠体内环孢素药代动力学的影响

目的:研究甘草连续给药7 d对环孢素在大鼠体内的药代动力学影响。方法:12只大鼠随机分为生理盐水对照组和甘草实验组,甘草实验组予甘草提取物(0.5 g/kg,1次/d)连续给药7 d,第8天晨两组均予环孢素灌胃给药后按时间点连续采样,采用荧光偏振免疫分析法测定环孢素的血药浓度,计算并比较主要药动学参数。结果:对照组和实验组的环孢素主要药动学参数Cmax、tmax、t1/2、AUC0-48 h、AUC0-∞、平均滞留时间(MRT)、药物清除率(CL/F)、表观分布面积(V/F)差异均无统计学意义(P>0.05)。结论:甘草连续给药7 d后不影响环孢素在大鼠体内的药代动力学。     

NONMEM法分析静滴异丙酚在中国人体的群体药代动力学

目的　考察中国人静脉匀速滴注异丙酚的群体药代动力学。方法　51例腰麻-硬膜外联合麻醉病人匀速输注异丙酚直至暴发脑电抑制,以HPLC法测定异丙酚血浆浓度,用NONMEM程序分析中国人异丙酚群体药代动力学。结果　异丙酚药代动力学符合三室线性开放模型,群体参数CL(L.min-1)、Vc(L)、Q2(L.min-1)、V2(L)、Q3(L.min-1)和V3(L)的标准值分别为1.10,7.63,1.54,15.0,0.76和175;体重对CL的校正为体重除以60的0.70次方,CL和Q2年龄≥60的病人较年龄<60的分别低18.1%和32.1%;年龄对V2和Q3的校正分别为年龄除以50的-0.66次方和-0.71次方。结论　NONMEM法对以三室模型群体参数估算的血药浓度值与实测值有良好相关性,体重、年龄对参数影响较大。     

Influence of lovastatin on the pharmacokinetics, toxicity and immunologic response of cyclosporine in the obese Zucker rat

The combined use of lovastatin, a hypolipidemic agent effective in the reduction of cholesterol levels, and the lipophilic immunosuppressant, cyclosporine, was studied in the obese rat model. Pharmacokinetics, immunosuppressive activity, lipid levels, and creatinine clearances were compared between groups administered drug-free vehicle, lovastatin or cyclosporine alone, or concomitant cyclosporine and lovastatin. All groups were pre-treated with either oral lovastatin 2.5 mg kg-1 day-1 or propylene glycol vehicle for 1 week. Although no differences in renal function were observed in rat groups administered cyclosporine or lovastatin alone, there was a significant reduction in baseline creatinine clearance following combination therapy compared to placebo controls (70 +/- 18 vs 121 +/- 16 per cent of baseline; p less than 0.05). No differences in trough cyclosporine concentrations were observed between groups. Similarly, mean areas under the whole blood concentration-time profiles were not significantly different with or without concomitant lovastatin (61823 +/- 27295 vs 41470 +/- 10312 ng h ml-1; p = 0.13). No differences in systemic clearance or volume of distribution of parent cyclosporine were observed with combination therapy. Furthermore, lipid levels and T-lymphocyte activity were unchanged with the addition of lovastatin. Per cent increases in creatine kinase were significantly correlated with percentage drop in baseline renal function, suggesting the development of rhabdomyolysis. The present data support the interaction between cyclosporine and lovastatin observed clinically, resulting in acute renal dysfunction. Caution should be exercised in their combined use.     

重组葡激酶群体药动学研究

目的:应用非线性混合效应模型(NONMEM)法研究重组葡激酶(r-SAK)的群体药动学.方法:建立双抗体酶联免疫吸附法(ELiSA)测定r-SAK的血浆药物浓度,应用NONMEM法进行模型优化,确定r.SAK的药动学模型和统计学模型,估算群体药动学参数和个体间、个体内变异,并进行统计分析.结果:建立了r-SAK的特异性浓度测定方法.r-SAK符合二房室一级消除模型,体重(WET)和肌酐对k21有显著性影响,方程为k21=θ(3)×WETθ(5),最终估算结果:k=0.19h-1,k12=1.93h-1,k21=1.87×10-4×WET11.8h-1,V=13.2L.计算所有参数的SE(Standard error)和95%CI(Confidence interva1)评价参数估算方法的优劣.结论:应用NONMEM法估算出的群体药动学参数结果可全面给出药物的药动学参数和变异,为r-SAK的安全性和有效性研究提供了丰富的依据.     

Analyzing Rich Data Using Different Methods Provided by NONMEM: Pharmacokinetics of Telmisartan Following Intravenous Infusion to Healthy Volunteers

Pharmaceutical Research -     

用NONMEM法建立中国癫痫儿童丙戊酸钠的群体药动学/药效学结合模型

目的:建立中国癫痫儿童应用丙戊酸钠(VPA)的群体药动学药效学(PPKPD)结合模型,为设计个体化用药方案奠定基础。方法:回顾性收集246例癫痫患儿应用VPA的临床数据。血药浓度是常规监测的稳态浓度。用246例患儿的数据,通过NONMEM法已经自行成功建立PPK模型。现将246例中单用VPA的69例的数据与已经建立的PPK模型结合,建立PPKPD模型。药效指标用癫痫发作次数减少百分比,分为5级。应用Logistic回归分析,拟合线性药效模型,用NONMEM法建立PPKPD模型,求算血药浓度获得某一级疗效的概率。结果:应用Logistic回归分析,拟合线性药效模型,求算出血药浓度获得某一级疗效的概率:血药浓度超过23μg·ml-1时,5级的概率小于50%,获得4、3、2级的最大概率及浓度为(30μg·ml-1,32.3%)、(50μg·ml-1,26.3%)、(65μg·ml-1,36.5%);血药浓度超过78μg·ml-1时,1级的概率大于50%;浓度为100μg·ml-1时,1级的概率约84.2%。结论:用NONMEM法成功地建立了中国癫痫儿童应用VPA的PPKPD模型,定量地求出某一血药浓度获得不同疗效等级的概率。     

吗替麦考酚酯在原发性肾病综合征患者中的群体药动学研究

目的：研究吗替麦考酚酯在原发性肾病综合征患者中的群体药动学模型,为临床个体化用药提供参考。方法选取2011年1月~2014年2月期间我院收治的56例原发性肾病综合征患者作为本组研究的观察对象,所有患者在给予吗替麦考酚酯对症治疗后,采集其血液样本,通过非线性混合效应模型构建出麦考酚酯的群体药动学模型,从而探讨患者的年龄、性别、身高、体重、剂量、血清肌酐、治疗时间等对药动学参数的影响。结果药动学基本模型采用一级吸收和消除的二房室模型最为有效;患者体重与治疗时间是吗替麦考酚酯清除率的主要因素;最终群体药动学模型为：清除率=0.476×体重×(1-e-1.17POD)。结论吗替麦考酚酯在原发性肾病综合征患者中的药动学模型具有明显的代表性,为个体化给药方案的确定提供依据。