尼莫地平对卡马西平的药物动力学影响

采用荧光偏振免疫分析法(FPLA),按自身对照法在六只家兔身上对卡马西平单用及与尼莫地平合用中卡马西平浓度变化进行观测.结果表明,合用尼莫地平后卡马西平药物动力学模型稍有改变.而单用与合用卡马西平后,其半衰期(T1/2)、药时曲线下面积(AUC)、消除率(CL)、表观分布容积(Vd)、峰浓度(Cmax)差异无统计学意义(P＞0.05).     

手性药物对映体的药物代谢动力学

目前世界上,临床应用的药物中具有光学活性的超过60%,而这些具有手性特征的药物中,绝大多数人工合成的药物通常是以外消旋体方式给药的[1～4]。药物的外消旋体引入体内后,其对映体分子均由体内具手性的蛋白质、酶和受体以两个不同的分子处理。因而,药物对映体在体内可具有不同的代谢途径和药理作用。随着现代先进的分析技术的发展,手性拆分技术得到进一步的提高,可以对生物体液中的手性药物的异构体进行分析测定,这使得研究手性药物在生物体内的药物代谢动力学过程成为可能,而这对深入研究手性药物的药理和毒理作用具有重大意义。手性药物的…     

姜黄素药物代谢动力学研究进展

目的 综述近几年姜黄素的药物代谢动力学研究.方法 对姜黄素临床前药代动力学以及临床药物代谢动力学进行分析.结果 姜黄素口服与注射半衰期短,生物利用度低.结论 姜黄素有广阔的应用前景,但是首先需要解决生物利用度的问题.     

尼莫地平片的相对生物利用度及药物动力学研究

目的　对尼莫地平片相对生物利用度及药物动力学进行研究。方法　采用反相高效液相色谱法 (RP HPLC)测定 10名志愿受试者单剂量口服 12 0mg尼莫地平片供试品与标准参比制剂后 ,尼莫地平血药浓度的变化。用 3p87药动学程序处理实验数据 ,并对实验结果进行配对t检验和双单侧t检验。结果　药时曲线下面积分别为 82 .5 1± 2 8.73ng·ml-1·h与 82 .92± 30 .93ng·ml-1·h ,达峰时间分别为 1.75± 0 .2 6h与 1.70± 0 .2 6h ,峰浓度分别为 2 8.84± 9.0 5ng·ml-1与 2 9.0 5± 8.6 9ng·ml-1。结果表明二者AUC、峰浓度及达峰时间无显著性差异 ,尼莫地平片供试品的相对生物利用度为 10 0 .70 %± 7.4 4 %。结论　尼莫地平片供试品与标准参比制剂为生物等效制剂。     

索西沙星在小鼠体内的药物代谢动力学研究

目的研究索西沙星在小鼠体内的药物代谢动力学,分析索西沙星的药物代谢动力学/药物效应动力学(PK/PD)参数。方法使用HPLC-MS/MS法,以莫西沙星为内标,以梯度甲醇-水为流动相,测定灌胃5 mg.kg-1后小鼠血液中索西沙星的含量。以WinNonlin软件计算动力学参数。结果小鼠血液中索西沙星Cmax为1.085μg.mL-1,Tmax为10 min,T1/2为1.425 h,AUC0～24为1.101μg.mL-1.h,对金黄色葡萄球菌、肺炎链球菌、流感嗜血杆菌、副流感嗜血杆菌和化脓链球菌的Cmax/MIC50均大于8。结论索西沙星在小鼠体内的吸收、分布及代谢较快,对多种细菌具有较好的活性。     

新生儿药物代谢动力学的特殊性

新生儿的身体和各种器官的功能 ,正处在生长发育阶段 ,其生理、生化和酶的活性 ,与成人具有量和质的差异。所以 ,新生儿用药后 ,在体内吸收、分布、代谢和排泄的动力学方面 ,均具有显著的特殊性。1　吸收新生儿胃内的ｐＨ值与年长儿和成年人相比 ,略呈碱性 ,而且胃肠排空速度较慢。因此 ,对于一些在酸性环境下不稳定的药物 ,如青霉素Ｇ、红霉素等 ,新生儿口服具有较好的吸收效果。而一些在酸性环境下才能被吸收或才具有活性的药物 ,如铁剂、胃蛋白酶、乳酶生等 ,新生儿口服 ,药物疗效将有所降低 ,需要同时服用酸性制剂如稀盐酸等来提高药物…     

丙泊酚药物代谢动力学研究概述

丙泊酚（propofol）即2，6-二异丙基苯酚，又名异丙酚，是一速效短效静脉麻醉药。由于其具有起效快、苏醒恢复迅速、持续输注后无蓄积等优点，迅速成为诱导、维持麻醉的首选药，广泛地用于神经外科麻醉、儿科麻醉、监测麻醉和ICU病房的镇静。靶控输注系统（Target-controlled infusion，TCI）以药物代谢动力学为基础，以血浆或效应室的药物浓度为指标，通过计算机程序控制药物输注，以达到按临床需要调节麻醉、镇静和镇痛深度的目的，不但方便而且提高了静脉麻醉的控制水平。近年来，TCI在国内外已成为丙泊酚给药的主要方式，而丙泊酚的药物代谢动力学是TCI的主要理论基础。因此，有必要对近年来国内外丙泊酚药物动力学特点进行研究，以使临床更为精确、安全应用TCI。     

尼莫地平片的药动学及生物等效性

目的 :研究尼莫地平片的药动学和相对生物利用度 ,验证该制剂与进口尼莫地平片的生物等效性。方法 :采用HPLC法测定 2 4名健康男性志愿者自身交叉单剂量口服国产尼莫地平片和进口尼莫地平片 12 0mg的经时血药浓度 ,计算主要药动学参数以及受试制剂的生物利用度。结果 :国产尼莫地平片和进口尼莫地平片的血药浓度 时间曲线符合一室模型 ,其主要药动学参数 :Cmax分别为 (83.9± 15 .4) μg·L-1与 (83.5± 12 .8) μg·L-1,Tmax分别为 (0 .5 7± 0 .0 6 )h与 (0 .6 7± 0 .0 8)h ,T1/2ke分别为 (1.80± 0 .16 )h与 (1.6 9± 0 .17)h ,AUC0 -t分别为 (16 0 .9± 15 .8) μg·h·L-1与 (15 6 .2± 18.7) μg·h·L-1。国产尼莫地平片对进口尼莫地平片的相对生物利用度为 (10 8.0± 7.2 ) %。结论 :国产尼莫地平片与进口尼莫地平片生物等效     

二种尼莫地平注射剂犬的药动学比较

目的研究尼莫地平乳剂型注射剂、注射剂在动物体内的药动学特征及生物等效性.方法采用双周期二制剂交叉试验设计,高效液相色谱法测定犬的血药浓度,DAS软件计算药动学参数.结果静脉注射尼莫地平乳剂型注射剂和尼莫地平注射液的AUC0-5h分别为(355.8±114.6),(338.9±83.0)h·μg·L-1;AUC0-∞分别为(356.8±114.5),(339.9±82.9)h·μg·L-1;t1/2α分别为(0.32±0.19),(0.27±0.17)h;t1/2β为(1.6±0.5),(1.46±0.27)h.方差分析结果表明,二制剂的主要药动学参数之间差异无显著性.试验制剂相对生物利用度为(103.7±11.2)%.结论二种制剂生物等效,但乳剂型注射剂安全性高于注射剂.     

尼莫地平口腔崩解片的药动学及相对生物利用度研究

目的研究尼莫地平口腔崩解片在人体内的药动学,比较其与市售尼莫地平片人体内药物动力学及相对生物利用度。方法将6名健康志愿者随机分成两组,交叉单剂量口服尼莫地平口腔崩解片A和市售片B各60 mg,采用HPLC法测定血浆中尼莫地平的浓度。结果口服尼莫地平口腔崩解片A和市售片B后,主要药代动力学参数分别为Cmax(256.23±54.64)g/ml、(102.415±36.96)g/ml;Tmax分别为(0.7049±0.035)h、(1.3317±0.123)h;T1/2分别为(0.2734±0.031)h、(1.1958±0.141)h;AUC0-t分别为(622.77±98.03)g/(ml.h)、(354.63±96.24)g/(ml.h)。尼莫地平口腔崩解片A相对于市售片B的人体生物利用度为177.27%。结论自制尼莫地平口崩片速释效果明显,并能提高生物利用度。     

Pharmacokinetics of nimodipine in patients with aneurysmal subarachnoid haemorrhage

Summary Patients with a ruptured supratentorial aneurysm undergoing early surgery after the subarachnoid haemorrhage were treated postoperatively with nimodipine to prevent delayed ischaemic dysfunction. It was given first as a continuous intravenous infusion 2 mg/h (mean dose 0.5 µg/kg/min) for at least 7 days, and then orally (45 mg × 6) for at least a further 7 days. During the i.v. infusion, the mean plasma concentration was 26.6±1.8 ng/ml. The plasma clearance ranged from 0.57 to 1.77 l/kg/h and was negatively correlated with the age of the patient. Immediately prior to successive oral doses, the mean plasma concentration was 13.2 ng/ml (range<3–38.8 ng/ml). The peak level was usually found after 1 h; it ranged from 7.0–96.0 ng/ml. Mean bioavailability was 15.9%. The nitropyridine metabolite was found in measurable concentrations only after oral treatment with nimodipine. In some cases, the concentration of metabolite exceeded that of the parent compound. The three patients investigated who developed delayed ischaemic dysfunction had plasma concentrations well within the range in patients who did not, so it seems unlikely that the therapeutic failure could be attributed to individual deviations in the pharmacokinetics of the drug.     

国产尼莫地平软胶囊人体相对生物利用度研究

10名健康男性志愿者随机自身交叉单剂量口服国产尼莫地平软胶囊和进口Bayer尼莫通片后,用高效液相色谱法测定血浆中尼莫地平浓度,尼莫地平两种制剂的体内药时数据符合二室模型,Cmax分别为27.15±77,38.02±14.83ng/ml;T_(max)为1.04±0.41,0.77±0.25h;t_(1/2)β为3.68±2.14,3.09±1.41h;AUC_(0-12)为 107.79±38.56,111.22±47.63μg.hL~(-1).两种制剂的相对生物利用度比较,国产尼莫地平软胶囊,其相对生物利用度为99.92%,表明国产尼莫地平软胶囊与进口尼莫通片属生物等效制剂.     

高效液相色谱-质谱联用法研究两种尼莫地平制剂的生物等效性

目的:评价两种国产尼莫地平片剂人体生物等效性.方法:采用单剂量双交叉实验设计,用高效液相色谱-质谱联用(HPLC-MS)法测定20名健康受试者口服两种尼莫地平片60 mg后的血药浓度.结果:受试制剂和参比制剂药-时曲线均符合一房室模型,t 1/2 分别为( 2.1 ± 0.3 )和( 2.2 ± 0.4 )h, t max 为( 1.5 ± 0.4 )和( 1.6 ± 0.4 )h, C max 为( 28.2 ± 7.1 )和( 28.8 ± 7.6 ) μg·L -1 , AUC为( 105.9 ± 29.5 ) 和( 106.5 ± 26.4 )μg· L -1 ·h,受试制剂的相对生物利用度为( 99.4 ± 5.3 )%.结论:经统计学分析,两种国产片具有生物等效性.     

尼莫地平漂浮缓释片的人体药物动力学及相对生物利用度

目的:比较尼莫地平(Nim)漂浮缓释片与普通片的药物动力学、相对生物利用度及体内外相关性.方法:10例男性健康受试者自身交叉对照、单剂量po Nim漂浮缓释片或普通片各120mg,采用HPLC法测定血浆Nim浓度,单室模型拟合药物动力学参数.结果:Nim缓释片和普通片的t_(max)分别为(2.83±0.45)和(0.87±0.27)h(P<0.01),C_(max)分别为(32.82±6.36)和(48.71±8.94)ng/ml(P<0.01),AUC分别为(204.81±45.03)和(159.98±39.96)h·ng/ml(P<0.01).数据经对数转换后进行双单侧检验,两种制剂生物不等效;缓释片的相对生物利用度为(129.89±17.02)%;其体内吸收与体外释药具有显著的相关性(P<0.01).结论:Nim漂浮缓释片生物利用度优于普通片,达到剂型设计要求.     

Investigation of nimodipine pharmacokinetics in Chinese patients with acute subarachnoid haemorrhage

Summary Nimodipine pharmacokinetics was investigated in 12 Chinese patients with acute subarachnoid haemorrhage receiving an IV infusion of 1.6 or 2 mg/h (based on estimated body weight) for 10 days. Peripheral venous blood samples were collected for up to 4 days and plasma nimodipine was assayed by GC/ECD. The mean value was taken as the steady state concentration (C_ss) and Clearance (CL) (hourly dose/C_ss) was calculated. Eight survivors were given oral nimodipine (60 or 90 mg) every 6h (based on body weight), blood was sampled over 6 h and the plasma nimodipine level determined. The values for C_ss, CL and CL·kg^–1 were 33.5 g·l^–1, 58 l·h^–1 and 1.0 l·h^–1·kg^–1 respectively; in survivors receiving the drug orally, bioavailability of the 30 mg tablet was 9%. In one very sick patient given crushed tablets by naso-gastric tube, the AUC was very low; in vitro studies indicated that adsorption of nimodipine by the tubing was unlikely to have been the cause.The pharmacokinetic findings in Chinese patients are comparable to previously reported values in Caucasians.     

Tolerability and pharmacokinetics of inhaled bimosiamose disodium in healthy males

AIMS: The aim of these first-in-human studies was to investigate the tolerability and the pharmacokinetics of bimosiamose disodium (TBC1269Z) administered by inhalation. METHODS: Two randomized, double-blind, placebo-controlled Phase I trials were performed in healthy males. In a single-dose escalating study 48 subjects received doses of 2-140 mg bimosiamose disodium by inhalation and in a multiple-dose study 32 subjects received 8-70 mg bimosiamose disodium twice daily. In both studies 4 ml of the drug solution was administered via nebulizer over 15 min. Adverse events, vital signs, ECG, clinical laboratory parameters and forced expiratory volume in 1 s (FEV(1)) data were recorded and nasopharyngeal examinations were performed to address the safety and tolerability. Blood was collected for the determination of plasma concentrations of bimosiamose. RESULTS: All subjects completed the study. No deaths or severe adverse events occurred. Eleven mild adverse events occurred in the dose-escalation study and 34 in the multiple-dose study after inhalation of bimosiamose disodium. Adverse events were more frequent at the highest dose (140 mg) of the dose-escalation study. For placebo treatment one moderate adverse event was observed in the dose-escalation study after placebo treatment, eight mild and three moderate adverse events occurred in the multiple-dose study. Bimosiamose was detected in plasma (maximum concentration 64 ng ml(-1)) only at doses > or =50 mg given twice daily and 105 mg once daily. For the highest dose a median value of 5746 h ng ml(-1) was determined for the AUC over the entire period of treatment of the multiple-dose study. CONCLUSION: The results suggest that single and multiple inhalation of bimosiamose disodium up to 70 mg is well tolerated in healthy males. Systemic bioavailability after inhalation is low.     

The pharmacokinetics of lamivudine in healthy Chinese subjects

AIMS: The purpose of this study was to investigate the pharmacokinetics of daily oral doses of lamivudine administered to healthy Chinese subjects for 1 week. METHODS: Twenty-four subjects were enrolled, 12 males and 12 females, all between the ages of 18 and 40 years. After an overnight fast, all subjects received a single oral dose of 100 mg lamivudine. Blood was obtained before lamivudine administration and at regular intervals to 24 h post dose. Subsequent doses were given once daily for a total of 7 days. On the last day another full pharmacokinetic profile was obtained to 24 h postdose. Timed urine collections were performed for all subjects on day 1 only. Pharmacokinetic parameters were calculated by using standard non compartmental techniques. RESULTS: Lamivudine was well absorbed in all subjects (tmax 1 h). On day 1 and day 7 the overall geometric mean Cmax was 1304 and 1385 ng ml-1, and AUC(0,24h) was 4357 and 4353 ng ml-1 h, respectively. On average 78% of the lamivudine dose was recovered in urine as parent compound. Pharmacokinetic parameters were very similar between male and female subjects, between day 1 and day 7 and in comparison with data obtained in many other pharmacokinetic studies. CONCLUSIONS: This study demonstrated that the pharmacokinetics of lamivudine are essentially identical between Chinese and Caucasian subjects, and between males and females. It confirms 100 mg lamivudine is an appropriate dose for use in Chinese patients, providing adequate exposure for optimal antiviral effect.