厄贝沙坦与氢氯噻嗪联用在肾性高血压大鼠体内药动学-药效学关系研究

目的:应用药动学-药效学结合模型研究厄贝沙坦与氢氯噻嗪联用在肾性高血压大鼠体内单剂量及多剂量用药时的药动学-药效学关系。方法:将SD大鼠制备成2肾1夹型肾性高血压模型,给大鼠单剂量或多剂量灌胃给药,分别于第1天和第8天连续的预定时间点测定血药浓度,同时测定动脉收缩压(SBP)和动脉舒张压(DBP)等药物效应,建立效应室药动学-药效学结合模型并计算相关的药动学和药效学参数。对单用、联用及单剂量、多剂量的药动学-药效学规律进行定量研究。结果:厄贝沙坦的药动学特征呈二室模型,氢氯噻嗪在非稳态和稳态条件下均未改变厄贝沙坦的药动学参数,而在稳态条件下,厄贝沙坦可增高氢氯噻嗪的血药浓度及曲线下面积。厄贝沙坦和氢氯噻嗪联用降压效应优于单用的效应。药物效应和效应室浓度之间符合Sigmoid-Emax药效学模型。单剂量下药物效应与血药浓度间存在滞后现象,多剂量下滞后现象消失。Emax、EC50、Keo等药效学参数在厄贝沙坦组和两药联用组之间的差异有统计学意义。结论:建立了PK-PD定量数学模型研究厄贝沙坦和氢氯噻嗪联用在大鼠体内单剂量和多剂量用药后药动学-药效学(暴露-反应)关系的规律,并提供了相关的药动学和药效学参数,可为临床合理用药提供参考依据。     

蝙蝠葛碱在犬体内的药代动力学和药效动力学研究

目的　应用药动学药效学结合模型方法研究蝙蝠葛碱在犬体内的药代动力学和药效动力学之间的关系。方法　4只beagle犬给蝙蝠葛碱6mg·kg-1静脉注射后,分时取血及行心电、血压及血流动力学变化观察。采用反相高效液相紫外法测定血浆中蝙蝠葛碱的浓度。结果　蝙蝠葛碱主要药动学参数T1 /2α,T1 /2β,Vd,AUC分别为(0 049±0 016)h,(2 .7±0. 6)h, (15. 8±3 5)L·kg-1和(1. 48±0. 17)mg·h·L-1。对Q Tc的最大延长率为( 25 5±9 4 )%;SBP,DBP,±(dp/dt)max的最大抑制率分别为( 23 .0±4. 9 )%,(21 .9±5. 9)%, ( 42. 8±6 .6 )%和( 39 .0±17 .1 )%。药理效应滞后于血药浓度10 ~15min。药理效应与效应室浓度之间的关系符合sigmoid Emax模型。结论　建立了蝙蝠葛碱在犬体内血药浓度、时间、药物效应三者之间的关系。     

国产厄贝沙坦胶囊的生物等效性研究

18名健康男性志愿者随机交叉单剂量口服厄贝沙坦胶囊和厄贝沙坦片剂300mg,进行药代动力学和相对生物利用度研究.血药浓度采用高效液相色谱法测定.结果表明胶囊和片剂的主要药代动力学参数Cmax分别为2.51±0.66和2.64±0.46mg·L-1,tmax分别为1.50±0.70和1.29±0.47 h,t1/2分别为10.28±4.48和10.13±5.42 h,AUC0-24分别为9.99±2.24和10.21±1.84 mg·h·L-1.相对生物利用度为98.13±12.52%,统计学结果显示胶囊和片剂生物等效.     

30例健康志愿者口服双环醇片剂的药代动力学研究

目的研究健康志愿者口服双环醇片剂的药代动力学.方法30名健康志愿者,随机分成25、50、100mg3个剂量组,分别给予单一剂量、多次剂量、餐前、餐后给药,用HPLC测定血药浓度,用3p97软件进行药代动力学分析.结果药代动力学符合一房室模型及一级动力学消除规律,3个剂量单次给药代动力学参数分别为t(1/2)ka(0.84±0.68)、(0.33±0.09)、(1.19±10.9)h.t(1/2)ke为(6.26±6.24)、(6.17±2.01)、(4.66±1.21)h.Vd/F为(455.02±135.35)、(622.94±325.37)、(688.83±308.14)L.CL/F为(93.45±67.66)、(83.31±71.97)、(104.30±45.76)L·h-1.cmax和AUC与剂量成正比.单次和多次口服双环醇片剂的药代动力学参数比较无显著差异.表明在一定剂量范围内,体内无蓄积现象.餐前、餐后的cmax分别为(151.26±39.00)和(222.64±43.22)μg·     

口服国产尼莫地平胶囊在健康人体的药代动力学研究

目的 :探讨国产尼莫地平胶囊在健康人体的药代动力学。方法 :用高效液相色谱法测定12名男性健康志愿者口服尼莫地平胶囊后的血药浓度 ;用3p97软件计算有关药代动力学参数。结果 :该制剂的T1/2β(h)、Tmax、Cmax、AUC0～6 分别为 (2 53±1 18)h、(0 42±0 14)h、(75 41±27 65)ng/ml、(155 85±49 54)ng/(h·ml) ,药 -时曲线符合二室开放模型。结论 :该制剂在体内滞留时间短 ,于0 4h左右达血药浓度峰值 ,其测定数据可为临床用药提供参考。     

生脉注射液中人参皂苷Rc在心绞痛患者体内的PK-PD相关性

目的 评价生脉注射液中人参皂苷Rc在心绞痛患者体内的药代动力学-药效动力学（PK-PD）相关性。方法 10名稳定性心绞痛受试者连续静脉滴注生脉注射液14 d,分别于给药后不同时间点采集血浆样品,采用液相色谱-串联质谱（LC-MS）法测定血浆中人参皂苷Rc的血药浓度,绘制药-时曲线,进行非房室模型拟合并计算PK参数;以受试者的收缩压（SBP）、舒张压（DBP）及心率（HR）作为药效指标,进行PK-PD结合模型的拟合,计算PK-PD参数。结果 人参皂苷Rc在心绞痛受试者体内的PK符合二室模型,其降压及加快HR的效应滞后于血药浓度,不与血药浓度直接相关;效应室浓度与药效之间具有良好的相关性,血压和HR的效应模型分别符合Inhibitory Effect Sigmoid I_max和Sigmoid E_max模型。结论 成功建立了生脉注射液中人参皂苷Rc在心绞痛患者体内的PK-PD结合模型,可有效地用于预测其血药浓度和效应,评价药效物质基础。     

非洛地平片在人体内药动学与药效学的相关性研究

目的:研究非洛地平片在人体内药动学与药效学的相关性。方法:采用液-质联用法测定10名健康受试者单剂量口服非洛地平10mg后的血药浓度,并以DAS2.0药动学模块程序处理药-时数据及计算药动学参数。分别于服药前及服药后不同时间对收缩压(SBP)、舒张压(DBP)、心率(HR)、平均动脉压(MAP)进行监测。结果:平均药动学参数tmax、Cmax、AUC0～48、AUC0～∞、Ka、t1/2分别为(3.88±0.35)h、(5.94±1.45)μg·L-1、(61.73±15.54)μg·h·L-1、(67.62±16.09)μg·h·L-1、(0.73±0.33)h-1、(15.43±4.15)h,以不同时间血药浓度分别对SBP、DBP、HR和MAP进行回归分析,其相关系数分别为0.614 6、0.985 6、0.907 7和0.568 6。用药2～8 h内DBP下降明显(P<0.05或P<0.01)。结论:非洛地平血药浓度与药效相关,其有效血药浓度约为2.64～5.84μg·L-1,临床应用非洛地平应重点监测DBP、HR。     

中国健康志愿者单剂静滴甲磺酸加替沙星注射液的药代动力学

目的:研究中国健康成年男性志愿者单剂静滴甲磺酸加替沙星注射液的药代动力学。方法:按药物临床试验管理规范(GCP)指导原则设计试验方案。选择9名受试者分别依次单刘静滴100,200和400mg的甲磺酸加替沙星注射液后,应用HPLC测定血药浓度,采用3P97软件进行数据处理,求出药代动力学参数。结果:受试者分别给药后,药-时曲线符合二房室模型,主要药代动力学参数C_(max)分别为1.10±0.19,2.17±0.33和3.16±0.47mg·L~(-1);t_(1/2)β分别为7.42±1.99,8.41±2.72和8.46±2.83h;AUC_(0-∞)分别为4.45 ±0.71,11.10±1.81和23.03±3.83mg h·L~(-1)。原形药主要经肾排泄,48h尿药累积排泄率分别为(43.08±15.79)％,(51.33±23.69)%和(45.67±18.22)％。结论:9名静滴甲磺酸加替沙星注射液后,药-时曲线符合二房室模型。提示甲磺酸加替沙星在100～400mg剂量内药物体内过程基本呈线性动力学特征而无饱和性,主要排泄途径为肾脏。     

血浆噻吗洛尔浓度及其降低心率作用的药动学及药效学结果分析

用药物动力学－药效学结合模型（ＰＫ－ＰＤ），对噻吗洛尔在兔体内的处置和效应动力学作定量分析。兔ｉｖ噻吗洛尔后，其效应变化明显滞后于血药浓度的变化，用ＰＫ－ＰＤ模型估算了其与这一滞后作用有关的效应动力学参数ｋｅｏ及与作用部位敏感性有关的药效学参数ＥＣ５０．兔ｉｖ４ｍｇ·ｋｇ后，Ｋｅｏ，ＥＣ５０分别为０．０９７±ｓ０．０２１ｍｉｎ，０．６±ｓ０．３ｕｇ·ｍＬ－１，本文用药物的时间－浓度－效应三维空间图描述效应和浓度随着时间变化的规律性。能直观地看出三者关系。     

法莫替丁对多潘立酮在健康人体药代动力学的影响

目的观察法莫替丁对多潘立酮药代动力学的影响。方法随机分组,10名健康志愿者未服和服用法莫替丁后单剂量口服多潘立酮10mg,用LC/MS/MS测定血药浓度,DAS软件计算药代动力学参数,t检验、非参数检验比较主要药代动力学参数。结果未服和服用法莫替丁后单剂量口服多潘立酮的血药浓度时间曲线均符合二室模型,达峰时间tmax分别为0.63±0.36、1.50±0.97h,峰浓度Cmax分别为9.91±5.45、4.30±5.01μg·L-1,曲线下面积AUC0-tn分别为39.57±10.46、32.43±9.61μg·h·L-1。服用法莫替丁后,多潘立酮的达峰时间延长,血药浓度时间曲线下面积减少,峰浓度降低,且均有统计学意义。结论在健康人体内,法莫替丁对多潘立酮的药代动力学参数影响显著。     

PK-PD modeling of irbesartan in healthy Chinese adult volunteers under non-steady-state conditions.

The purpose of this study was to construct a pharmacokinetic/pharmacodynamic model (PK-PD model) of irbesartan in healthy Chinese adult volunteers under non-steady-state conditions and provide relevant PK/PD parameters for use in clinical practice. Thirty-six healthy Chinese adult male volunteers received 150 or 300 mg irbesartan orally in tablet form (2 groups; n = 18 per group). Plasma concentrations were determined by HPLC and pharmacological effects, including effects on systolic (SBP) and diastolic blood pressure (DBP) were measured simultaneously. The experimental data were quantitatively analyzed according to the PK-PD model construct. PK/PD parameters were calculated. Blood pressure remained almost unchanged at an irbesartan dose of 150 mg under non-steady-state conditions. After a single dose of 300 mg, the pharmacokinetic profiles of irbesartan conformed to a two-compartment model. There were hysteresis loops between drug effects and plasma concentrations. The relationship between effects and effect compartment concentrations (Ce) could be represented by the sigmoid-Emax model. The Emax values for the inhibitory effects on SBP and DBP of irbesartan were 14.8 +/- 1.5 and 9.8 +/- 2.1 mmHg respectively, the EC50 values were 0.29 +/- 0.11 and 0.18 +/- 0.07 microg x ml(-1), while the K(eo) values were 0.62 +/- 0.09 and 0.68 +/- 0.07 h(-1), respectively. The PK-PD model of irbesartan was developed in healthy Chinese adult male volunteers, and may provide a more rational basis for dosage individualization.     

Pharmacokinetic and pharmacodynamic population modeling of orally administered rabeprazole in healthy Chinese volunteers by the NONMEM method.

The pharmacokinetic-pharmacodynamic (PK-PD) relationship of the proton pump inhibitor rabeprazole in healthy Chinese volunteers was characterized via a population approach. Healthy Chinese male volunteers were enrolled in the clinical trial. Subjects were divided into three groups by their CYP2C19 genotype. Serum concentrations of rabeprazole were determined using high performance liquid chromatography (HPLC). The intragastric pH values were monitored simultaneously. Data analysis was performed using nonlinear mixed-effects modeling as implemented in the NONMEM software package. The final PK-PD model incorporated a one-compartment PK model with one-order absorption from the gastroenteric trace, first-order elimination pathway with one fixed-effect genotype modeling, and a full sigmoidal Emax PD model (X +/- SE: E0 = 2.30 +/- 0.189; Emax = 7.32 +/- 0.662; EC50 = 51.3 +/- 2.142 ng/ml; Hill coefficient = 5.00 +/- 0.556). The time profiles for concentration and pH value, as well as the concentration-pH value relationship of rabeprazole in healthy Chinese volunteers were well described by the developed population PK-PD model.     

Inhibition of the acute effects of angiotensin II by the receptor antagonist irbesartan in normotensive men

Irbesartan (SR 47436, BMS 186295) is an imidazole derivative that specifically binds to the angiotensin type 1 receptor. The purpose of this study was to assess the inhibitory effect of irbesartan on the pressor action of exogenous angiotensin II in healthy subjects, to evaluate the dose dependency and duration of this inhibition, and to determine the effect of irbesartan on plasma components of the renin-angiotensin system. Forty-two healthy male volunteers maintained on ad libitum sodium intake were enrolled in a randomized, double-blind, placebo-controlled, parallel-design, dose-ranging study. On 2 study days 1 week apart, volunteers were given either a placebo or the active drug at one of the chosen doses (5, 25, 50, 75, 100, 150, or 300 mg). The pressor effects of an individually titrated test dose of exogenous angiotensin II as well as plasma levels of angiotensin II, active renin, aldosterone, and treatment drug were determined before and throughout the 24 h after drug administration. The inhibitory effect of irbesartan on the pressor response to angiotensin II was observed within 1 h after dosing, peaked between 2 and 4 h, and lasted more than 24 h for doses of 25 mg and more. The effect was clearly dose related. Two and 24 h after administration of irbesartan, 300 mg, the response of arterial blood pressure (systolic and diastolic) to a given dose of angiotensin II was reduced by approximately 100% and 60%, respectively. Plasma concentrations of angiotensin II and active renin increased markedly after irbesartan administration, whereas plasma concentrations of aldosterone decreased. No evidence was found that the high levels of circulating angiotensin II observed after irbesartan administration could override the inhibitory effect of irbesartan on any of the measured parameters up to 24 h after dose. In conclusion, irbesartan appears to be a well-tolerated, orally active, potent antagonist of the renin-angiotensin system in men.     

Pharmacokinetic-pharmacodynamic modeling of testosterone and luteinizing hormone suppression by cetrorelix in healthy volunteers

Cetrorelix (CET), a potent luteinizing hormone-releasing hormone (LH-RH) antagonist, was recently approved for the prevention of premature ovulation in patients undergoing a controlled ovarian stimulation (COS), followed by oocyte pickup and assisted reproductive techniques (ART), and is currently under clinical trials for benign prostate hyperplasia, endometriosis, and tumors sensitive to sex hormones. CET suppresses luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T) in men. The purpose of this study was to evaluate the pharmacokinetics and absolute bioavailability of 3 mg intravenously and subcutaneously administered CET in healthy male and female volunteers and to develop a pharmacokinetic-pharmacodynamic (PK-PD) model to link the plasma concentrations of CET to the T and LH suppression in males. Following intravenous (IV) (n = 5) and subcutaneous (SC) (n = 6) administration of CET acetate, CET and hormone plasma levels were measured by radioimmunoassay (RIA) and enzyme immunoassay (EIA) methods, respectively. Pharmacokinetics of CET was explained by a three-compartment model for the IV route and by a two-compartment model with first-order absorption for the SC route. Average absolute bioavailability after SC administration was 85%. There were no differences in the pharmacokinetics between male and female subjects (ANOVA, p > 0.05). Single IV and SC doses of CET caused immediate and distinct suppression of LH, FSH, and T levels by 80%, 45% and 95% of their baseline levels, respectively. The duration of hormone suppression was longer for the SC route. An indirect-response PK-PD Emax model was developed to link the measured CET plasma concentrations with the respective T or LH levels. In addition, the circadian rhythm of T levels was accounted by including a cosine function in a second separate PD model. The PD model with cosine function was applied to T baseline levels as well as to the suppressed concentrations after CET dosing. The two models adequately described the PK-PD relationship between plasma levels of CET and T suppression following IV and SC dosing. The EC50 values (mean +/- SD) for the suppression of T were similar (p > 0.05) between the two routes of administration and the two models.     

厄贝沙坦氢氯噻嗪胶囊在健康人体的生物等效性

目的研究厄贝沙坦氢氯噻嗪胶囊(抗高血压药)在健康人体的生物等效性。方法 22名健康志愿者,随机双交叉单剂量口服厄贝沙坦氢氯噻嗪胶囊(试验制剂)和厄贝沙坦氢氯噻嗪片(参比制剂),剂量为厄贝沙坦300 mg、氢氯噻嗪25 mg。分别于服药后36 h内,多点抽取静脉血,用高效液相色谱法分别测定血浆中厄贝沙坦和氢氯噻嗪的浓度。用DAS程序计算相对生物利用度,并评价2种制剂生物等效性。结果单剂量口服厄贝沙坦氢氯噻嗪胶囊和片剂后的药代动力学参数,厄贝沙坦:Cmax分别为(2.61±0.62)和(2.57±0.46)mg·L-1;AUC0-36分别为(15.14±3.43)和(15.39±3.91)mg·h·L-1;AUC0-∞分别为(16.37±3.42)和(16.80±4.28)mg·h·L-1;相对生物利用度为(100.75±19.42)%。氢氯噻嗪:Cmax分别为(162.51±27.55)和(168.18±25.71)μg·L-1;AUC0-36分别为(1115.41±147.34)和(1144.15±171.62)μg·h·L-1;AUC0-∞分别为(1212.68±160.77)和(1252.75±211.2...     

Comparison of different pharmacodynamic models for PK-PD modeling of verapamil in renovascular hypertension

INTRODUCTION: The aim of this work was to compare the suitability of different pharmacodynamic models for PK-PD modeling of verapamil cardiovascular effects in aortic coarctated rats (ACo), a model of renovascular hypertension. METHODS: A "shunt" microdialysis probe was inserted in a carotid artery of anaesthetized sham-operated (SO) and ACo rats for determination of verapamil plasma concentrations and their effects on blood pressure and heart rate after intravenous application (1 and 3 mg kg(-1)). Correlation between verapamil plasma levels and their cardiovascular effects was established by fitting data to a linear, and a conventional and modified E(max) model. RESULTS: No differences in verapamil volume of distribution were observed between experimental groups. Whilst clearance increased with dose in SO rats, no differences were found in verapamil clearance in ACo comparing both dose levels. A good correlation between verapamil plasma unbound concentrations and their hypotensive and chronotropic effects was found in both experimental groups using the tested PK-PD models. Although all pharmacodynamic models allowed a precise estimation of verapamil PK-PD parameters, linear and E(max) model did not permit an accurate PK-PD parameter estimation for the hypotensive and chronotropic effect, respectively. Conversely, the modified E(max) model allows both a precise and accurate estimation of PK-PD parameters for verapamil effects. Although, absolute verapamil blood pressure lowering effect was greater in ACo rats compared with SO rats, no differences were found in verapamil PK-PD parameters estimated for the hypotensive response. DISCUSSION: Side-by-side comparison of the tested pharmacodynamic models showed that accuracy of PK-PD parameters estimation by using the linear and classical E(max) model depends on the magnitude of concentration-effect curve covered in the study. Conversely, the modified E(max) model allowed both a precise and accurate estimation of PK-PD parameters, suggesting that the modified E(max) pharmacodynamic model is the most suitable for verapamil PK-PD modeling.     

Pharmacokinetic and pharmacodynamic interaction between irbesartan and hydrochlorothiazide in renal hypertensive dogs

Combined irbesartan/hydrochlorothiazide (HCTZ) formulations are often used clinically. Pharmacokinetic-pharmacodynamic (PK/PD) modeling was applied to investigate the pharmacokinetic and pharmacodynamic interaction between irbesartan and HCTZ in renal hypertensive dogs at non-steady-state and steady-state. The renal hypertensive dogs were treated with oral irbesartan alone, or HCTZ alone, or the combination of irbesartan and HCTZ for 8 days. Blood pressure and plasma concentrations were measured and pharmacokinetic-pharmacodynamic parameters were analyzed. Irbesartan showed a two-compartment model pharmacokinetic profile. The concentration-time course of irbesartan was not changed by HCTZ, but irbesartan increased the peak plasma concentration and area under the curve of HCTZ at steady-state. HCTZ had no blood pressure lowering effect at non-steady-state. Irbesartan plus HCTZ had greater blood pressure lowering action than irbesartan alone. HCTZ increased actions of irbesartan. Hysteresis loops were found between effect and plasma concentrations of irbesartan after a single dose. However, hysteresis loops disappeared at steady state with more rapid realization of maximum concentration and effects. The relationship between effects and effect-compartment concentrations of the drugs was represented by a sigmoid Emax model. The results suggest synergistic pharmacodynamic interaction between irbesartan and HCTZ in renal hypertensive dogs and some differences of pharmacokinetic-pharmacodynamic properties between irbesartan and irbesartan/HCTZ combinations at non-steady-state and steady state.     

Simultaneous modeling of the pharmacokinetic and pharmacodynamic properties of benzodiazepines. I: Lorazepam

This investigation compares the time course changes in the central nervous system (CNS) impairment effects on psychomotor and cognitive skills and relates these changes to the plasma lorazepam concentrations in a pharmacokinetic-pharmacodynamic (PK-PD) model. Six male subjects received a single oral dose of lorazepam or placebo. The CNS effects were measured by using computerized continuous tracking (TRKN), body sway with eyes open (SWAY OPEN), and digit symbol substitution (DSS) tests. Plasma lorazepam concentrations were best characterized by a two-compartment model with first-order absorption. Plotting the plasma lorazepam concentration and measured effect across time revealed a counterclockwise hysteresis loop. Fitting the time course of the effects in an integrated PK-PD model required an effect compartment with the equilibrium rate constant between it and the plasma compartment. The magnitude of the temporal lag was quantified by the half-time of equilibration between concentration in the hypothetical effect compartment and the plasma lorazepam level (t1/2keo). The CNS effect measured by TRKN was characterized by a mean estimate of maximum predicted effect (Emax) of 418 with a t1/2keo of 0.43 hr, an estimate of effect site drug level to produce 50% of Emax (EC50) of 35.8 ng/ml and a power parameter (gamma) of 6.29. Corresponding parameter mean estimates for SWAY OPEN and DSS as measures of drug CNS effect were quite similar.