双环醇对利福平和异烟肼在大鼠体内药代动力学的影响

目的：研究双环醇对利福平和异烟肼血药浓度及药代动力学参数的影响。方法：应用HPLC法测定与双环醇联用前后利福平和异烟肼的血药浓度,以DAS2．0药代动力学程序拟合药动学参数。结果：双环醇与利福平合用、双环醇与异烟肼合用、双环醇与利福平和异烟肼同时合用的各时间点中,除异烟肼6h的血药浓度三药合用组与其他组有显著性差异（P〈0．05）之外,其余时间点的血药浓度值在各组间均无显著性差异（P〉0．05）;药动学参数AUC（药时曲线下面积）（0-t）、AUC（0-∞）、MRT（体内平均驻留时间）（0-t）、MRT（0-∞）、t1/2x（半衰期）、tmax（达峰时间）、CLx/F（清除率）、Vx/F（表现分布容积）、Cmax（血药峰浓度）各组间均无显著性差异（P〉0．05）。结论：双环醇与利福平合用或与异烟肼合用,以及与利福平和异烟肼两药合用,均未见对利福平和异烟肼药动参数有明显影响。     

高效液相色谱法测定血浆中硫唑嘌呤和巯嘌呤浓度

本文报道用高效液相色谱法测定人血浆中硫唑嘌呤和巯嘌呤浓度的方法。样品用三氯醋酸沉淀蛋白后，取上清液直接进样。以ＳｐｈｅｒｉｓｏｕｂＣ１８为固定相，甲醇－水－乙二胺（２００：８００：１０Ｖ／Ｖ）为流动相，检测波长为ＵＶ３１３ｎｍ，甲硝唑为内标。硫唑嘌呤和巯嘌呤最低检出浓度分别为０．１μｇ／ｍｌ和０．５μｇ／ｍｌ；平均回收率分别为９６．６±２．７２和１０３．４±２．６５。     

硫唑嘌呤和巯嘌呤增加淋巴瘤风险

根据一项荟萃分析的结果，与一般人群相比，炎症性肠病（IBD）患者应用硫唑嘌呤（azathioprine）（Ⅰ）或巯嘌呤（mercaptopurine）（Ⅱ）发生淋巴瘤的风险约增加4倍。     

氯沙坦对家兔环孢素A药代动力学影响的研究

目的研究氯沙坦对家兔环孢素A（CsA）药代动力学的影响。方法采用荧光偏振免疫法（FPIA法）测定6只家兔合用氯沙坦前后CsA的血药浓度,并对2组（单用CsA组和合用氯沙坦组）药代动力学参数进行分析。结果合用氯沙坦组的CsA峰浓度（Cmax）、曲线下面积（AUCν0-24）均显著升高（P〈0．01）,血浆清除率（cL）及表观分布容积（V）均显著降低（P〈0．05或P〈0．01）,其余药动学参数无显著性变化（P〉0．05）。结论合用氯沙坦可升高CsA的血药浓度,临床上其与CsA合用需监测CsA的血药浓度,保证治疗的安全有效。     

肿瘤多药耐药逆转剂HZ08对阿霉素在大鼠体内药动学影响

 目的：考察肿瘤多药耐药逆转剂HZ08与阿霉素联用对阿霉素在大鼠体内药动学的影响。方法：采用LC-MS/MS法测定HZ08和阿霉素的血药浓度,以DAS 2.0软件计算药动学参数,大鼠尾静脉注射HZ08和阿霉素,与对照组分别单独注射阿霉素和HZ08以及阳性药组注射维拉帕米相比较,考察HZ08与阿霉素联用对阿霉素药动学影响。结果：HZ08未显著改变阿霉素的主要药动学参数,与阿霉素联合用药对HZ08自身在大鼠体内的药动学也无显著影响,阳性药维拉帕米则显著增加阿霉素药时曲线下面积（AUC）和血药峰浓度（Cmax）。结论：HZ08与阿霉素联用对阿霉素大鼠体内药动学无显著影响。     

普罗帕酮对氨茶碱药物动力学的影响

本实验采用自身对照法观察氨茶碱、氨茶碱和普罗帕酮（Propafenose,心律平）占用后血清茶碱浓度的变化，按一室模型公式求算茶碱的有关药动学参数．实验结果表明：两药合用，茶碱的肌体清除率降低25％、半衰期延长，清除速率减慢（P＜0．05）．而茶碱的吸收和分布没有明显变化（Ka、Auc，P＞0．05）。     

阿维莫泮在中国健康受试者中的药动学研究

目的：研究在中国健康志愿者中单次及多次口服阿维莫泮胶囊后阿维莫泮及其代谢产物ADL08—0011的药动学特征。方法：共入组24例受试者,其中12例受试者参加6、12、18mg3个剂量组单次给药药动学研究,采用随机开放、3×3拉丁方试验设计;在完成3个周期的单次试验后,继续进行连续多次给药药动学试验,给药方法为每天给药2次,每次给药12mg,共给药6d。另外12例受试者参加24mg剂量单次给药药动学研究。采用LC—MS／MS法测定人血浆中阿维莫泮及代谢产物ADL08—00Il浓度,应用Win—Nonlin6．1软件计算药动学参数。结果：阿维莫泮在0．192～75肛g／L范围线性良好,特异性、精密度、准确度及回收率都符合生物样本测试要求。6、12、18、24mg单次给药的主要药动学参数如下：Cmax（8．79±6．10）、（18．30±9．92）、（31．48±13．68）、（32．91±17．95）／ug／L;tmax（1．4±0．6）、（1．8±0．6）、（1．8±0．6）、（2．1±0．6）h;AUClast（33．2±23．0）、（60．3±28．9）、（94．1±42．2）、（112．0±57．5）ug·h·L-1t1/2（8．4±4．9）、（8．4±5．3）、（7．9±4．8）、（10．0±4．3）h（218．1±111．8）、（234．7±135．7）、（295．3）、（256．9±132．5）L／h。多次给药CL／F7．6±12mgbid）的主要药动学参数如下：Cmax（16．57±10．15）ug／L,tmax（1．6±1．0）h,AUCl。。。（64．4±32．0）ug·h·L-1,t1/2（12．0±3．3）h,CL／F（258．4±109．4）L／h。结论：该方法准确灵敏,适用于阿维莫泮的药动学研究。阿维莫泮在6～18mg剂量范围内的单次给药以及12mgbid的多次给药人体药动学特征都符合线性动力学过程,而24mg剂量单次给药则吸收过程出现非线性动力晕过程．     

福辛普利在肝功能受损患者体内的药动学

福辛普利（fosinopril）是一种新型的含膦酸结构的ACE抑制剂，它也是一个前体药物，在人体内被代谢成为活性福辛普利酸（fosino－prilat）。与其它同类药所不同的是，本品通过肝肾双重途径清除。据报道，本品在肾功能受损患者体内的肾清除率减低，但由于全身清除率无明显改变，因此其药动学基本不变。本文研究了福辛普利和福辛普利酸在肝功能受损患者体内的单剂和稳态药动学。两组受试者，其中健康人组6例，肝病组（均属酒精性肝硬化）12例，ICG清除率分别为11．31土2．02和4．46土2．65mL·min－‘·kg－‘，肌酸醉清除率均为正常，血压…     

在大鼠体内联苯双酯对环孢素A药代动力学的影响

目的：探讨联苯双酯（bifendate，BDD）与环孢素A（cyclosporin，CsA）在大鼠体内合用后，联苯双酯对环孢素A药动学过程的影响。方法：随机分成治疗组和安慰剂组进行随机平行对照实验。用HPLC法测定大鼠全血中环孢素A浓度，采用非隔室模型方法计算药动学参数，并进行统计学比较。结果：环孢素A与联苯双酯合用后，前者在大鼠体内的血药浓度普遍降低，相对清除率（CL/F）显著增大（P〈0．05），生物半衰期（t1/2）显著缩短（P〈0．05），其余参数差异无统计学意义（P〉0．05）。结论：联苯双酯可明显降低环孢素A的血药浓度。联苯双酯与环孢素A合用时必须监测环孢素A的血药浓度。     

阿奇霉素对大鼠灌服华法林的药效学和药动学的影响

目的：研究抗生索阿奇霉素对大鼠灌服华法林的药效学指标凝血酶原时间（PT）和国际标准化比值（INR）以及药动学指标血药浓度的影响。方法：将SD大鼠随机分成两组：单用华法林组（A组）和华法林＋阿奇霉素合用组（B组）,每组大鼠灌胃给予华法林0．2mg·kg^-1,每日1次,连续613,其中B组大鼠在第6日最后1次灌胃给予华法林后立即腹腔注射阿奇霉素80mg·kg^-1,且开始计时,分别于0．25、0．5、1．5、2．5、3．5、5、7、10、13小时采血,测定PT,计算INR。并建立HPLC法,测定华法林血药浓度。结果：从5小时开始,B组大鼠的胛值较A组显著增大（P〈0．05）,INR值最高可达7．5;B组大鼠的华法林药动学参数咒。较A组显著延长（P〈0．01）,其他药动学参数无显著性差异;两组大鼠的INR-C曲线都呈逆时针走向,且B组的逆时针效应更甚。结论：阿奇霉素与华法林合用可发生药效学和药动学相互作用,增强华法林的抗凝作用,增加用药者的出血风险,故临床上两药合用时应密切监测用药者的INR值,避免严重不良反应的发生。     

Pharmacokinetics of 6-mercaptopurine in patients with inflammatory bowel disease: implications for therapy

Proper prospective pharmacokinetic studies of 6-mercaptopurine (6-MP) in inflammatory bowel disease (IBD) patients are lacking. As a result, conflicting recommendations have been made for metabolite monitoring in routine practice. The authors have evaluated 6-MP pharmacokinetics in IBD patients, including the genetic background for thiopurine methyltransferase (TPMT). Red blood cell (RBC) 6-thioguanine nucleotide (6-TGN) and 6-methylmercaptopurine ribonucleotide (6-MMPR) concentrations were measured in 30 IBD patients at 1, 2, 4, and 8 weeks after starting 6-MP, 50 mg once daily. Outcome measures included mean 6-TGN and 6-MMPR concentrations (+/- 95% confidence interval, CI95%) and their associations with TPMT genotype, 6-MP dose, and hematologic, hepatic, pancreatic, and efficacy parameters during the 8-week period. Steady-state concentrations were reached after 4 weeks, indicating a half-life of approximately 5 days for both 6-TGN and 6-MMPR; the concentrations were 368 (CI95% 284-452) and 2837 (CI95% 2101-3573) pmol/8 x 10 RBCs, respectively. Large interpatient variability occurred at all time points. TPMT genotype correlated with 6-TGN concentrations (0.576, P < 0.01), and patients with mutant alleles had a relative risk (RR) of 12.0 (CI95% 1.7-92.3) of developing leukopenia. A 6-MMPR/6-TGN ratio less than 11 was associated with therapeutic efficacy. Based on this pharmacokinetic analysis, therapeutic drug monitoring is essential for rational 6-MP dosing.     

The transfer of 6-mercaptopurine in the dually perfused human placenta

The immunosuppressant azathioprine is increasingly being used in pregnancy. The human placenta is considered a relative barrier to the major metabolite, 6-mercaptopurine (6-MP), and likely explains the lack of proven teratogenicity in humans. The aim of this study was to determine how the human placenta restricts 6-MP transfer using the human placental perfusion model. After addition of 50 ng/ml (n=4) and 500 ng/ml (n=3) 6-MP into the maternal circulation, there was a biphasic decline in its concentration and a delay in fetal circulation appearance. Under equilibrative conditions, the fetal-to-maternal concentration ratio was >1.0 as a result of ion trapping. Binding to placental tissue and maternal pharmacokinetic parameters are the main factors that restrict placental transfer of 6-MP. Active transport is unlikely to play a significant role and drug interactions involving, or polymorphisms in, placental drug efflux transporters are not likely to put the fetus at risk of higher 6-MP exposure.     

川芎嗪对大鼠灌服环孢素A药代动力学的影响

目的研究中药成分川芎嗪(TMP)对大鼠灌服环孢素A(CsA)药代动力学的影响。方法40只雄性SD大鼠按体重进行随机区组设计，分为4组。试验d 1，每只大鼠灌服CsA(10 mg·kg^-1)后，于0，1，2，3,4，6，8，12，24，36和48 h从尾静脉处采血0.2～0.25 mL。然后各组大鼠从试验的d 4到d 8进行不同的预处理，即每日分别灌服蒸馏水、维拉帕米(Ver)、低剂量和高剂量的TMP。d 9时各组大鼠单次合用CsA(10 mg·kg^-1)和上述的各种化合物后，按d 1的时间点采样。用HPLC法测定全血中CsA的浓度，计算其主要药代动力学参数并进行统计学分析。结果合用蒸馏水组的CsA药代动力学参数前后无显著性差异；Ver预处理并合用后，CsA的AUC^{0-48 h}和C_max均显著增加(P<0.01和P<0.05)，T^1/2β显著延长(P<0.05)，CL显著降低(P<0.05)，而T_max和V的变化无统计学差异。低剂量TMP预处理并合用后，CsA的AUC^{0-48 h}和C_max有增加的趋势，但无统计学差异，其余药代动力学参数的变化也无统计学的差异。高剂量TMP预处理并合用后，CsA的AUC^{0-48 h}和C_max均有显著的增加(P<0.01)，但其他药代动力学参数的变化无统计学差异。结论高剂量的TMP能显著提高CsA的灌服生物利用度，但对CsA的体内消除过程几乎没有影响。     

Effects of vehicles and prodrug properties and their interactions on the delivery of 6-mercaptopurine through skin: bisacyloxymethyl-6-mercaptopurine prodrugs

A series of S6,9-bisacyloxymethyl-6-mercaptopurine (6,9-bis-6-MP) prodrug derivatives was synthesized and characterized. The solubilities of the derivatives in solvents (vehicles), which exhibited a wide range of polarities from water to oleic acid, were measured. The abilities of the prodrugs to deliver 6-mercaptopurine (6-MP) from the vehicles have also been determined, and experimental fluxes and permeability coefficients (Kp) have been calculated for a large number of prodrug: vehicle combinations. Generally the best prodrugs of the series in terms of delivering 6-MP, regardless of the vehicle, were the first two members--the bisacetyl- and the bispropionyloxymethyl-6-mercaptopurine prodrugs. This result has been attributed mainly to the increased water solubility of these two prodrugs compared with that of 6-MP and the other prodrugs, since all of the prodrugs are much more lipid soluble than 6-MP. For three vehicles--isopropyl myristate, propylene glycol, and water--there was a good correlation between log experimental Kp for the delivery of 6-MP by the prodrugs from those vehicles and the theoretical solubility parameters of the prodrugs. The stabilities of the bisacetyl-(2), bisproprionyl-(3), and bisbutyryloxymethyl-6-mercaptopurine (4) derivatives were determined in buffer and in buffer containing enzymes leached from the dermis. Prodrug 2 was more stable than 3 or 4 in the buffer containing the enzymes, while 4 was more stable than 2 or 3 in the plain buffer.     

左旋氧氟沙星对苯妥英钠在家兔的药代动力学影响的研究

目的 :研究左旋氧氟沙星对苯妥英钠血药浓度及药代动力学参数的影响。方法 :应用紫外分光光度法测定家兔喂服左旋氧氟沙星前及10d后单剂量静脉注射苯妥英钠的经 -时血药浓度 ,以“3p87”药代动力学程序拟合药动学参数。结果 :苯妥英钠经 -时血药曲线符合二室开放模型 ,合用左旋氧氟沙星后 ,苯妥英钠血药浓度均有不同程度的降低 ,部分药代动力学参数也有明显的改变。结论 :提示两药合用使苯妥英钠代谢明显加快     

Effects of vehicles and prodrug properties and their interactions on the delivery of 6-mercaptopurine through skin: S6-acyloxymethyl-6-mercaptopurine prodrugs

A homologous series of S6-acyloxymethyl-6-mercaptopurine (6-mono-6-MP) and two 9-acyloxymethyl-6-mercaptopurine (9-mono-6-MP) prodrugs have been synthesized and characterized. The ability of the 6-mono-6-MP prodrugs to deliver 6-mercaptopurine (6-MP) through hairless mouse skin from isopropyl myristate (IPM) and propylene glycol (PG) has been evaluated. There was a good correlation between the log experimental permeability coefficients from the diffusion data and calculated solubility parameters of the prodrugs. Although there was no statistical difference between the rates of delivery of 6-MP by the acetyl through valeryl 6-mono-6-MP prodrugs from IPM, the butyryl and valeryl prodrugs were significantly better at delivering 6-MP from PG. For a given solubility parameter value, the 6-mono-6-MP prodrugs were less soluble in water and IPM, and more soluble in PG than the previously studied S6,9-bisacyloxymethyl-6-MP (6,9-bis-6-MP) prodrugs. On the other hand, for a given solubility parameter, the 6,9-bis-6-MP prodrugs were generally more effective at delivering 6-MP from IPM and PG. The single 9-mono-6-MP prodrug that was evaluated was much less effective at delivering 6-MP than either the 6-mono- or 6,9-bis-6-MP prodrugs. Thus, it is much less important to mask the imidazole than the thionamide functional group in 6-MP to enhance the topical delivery of 6-MP using a prodrug approach.     

Fine Multiple Emulsions Bearing 6-Mercaptopurine: In Vitro and In Vivo Antitumor Studies

Fine multiple emulsions were prepared by a two-step emulsification using the sonication technique. 6-mercaptopurine (6-MP) was encapsulated in the internal aqueous phase. It was coated with a phospholipid derivative of polyethylene glycol (PEG-PC). The coated multiple emulsion was characterized for antitumor activity on the murine leukemia cell line L-1210 in vitro. A decreased uptake and cytotoxicity were observed for PEG-PC-coated multiple emulsion in vitro, compared with uncoated ones. The IC₅₀ (50% inhibitory concentrated) was also decreased 1.64 times. In vivo antitumor activity was recorded as mean survival time (MST) of mice injected intravenously or intraperitoneally with tumor cells or, treated with 6-MP formulations through similar routes. MST was increased upon treatment. The normal peritoneal cells remained unchanged while blood parameters were restored with multiple emulsion treatment to tumor-bearing mice. The efficacy of the formulation was mainly due to the slow release and effective delivery of the drug from the formulation, suggesting its potential use for the treatment of cancer.     

Fine Multiple Emulsions Bearing 6-Mercaptopurine: In Vitro and In Vivo Antitumor Studies

Fine multiple emulsions were prepared by a two-step emulsification using the sonication technique. 6-mercaptopurine (6-MP) was encapsulated in the internal aqueous phase. It was coated with a phospholipid derivative of polyethylene glycol (PEG-PC). The coated multiple emulsion was characterized for antitumor activity on the murine leukemia cell line L-1210 in vitro. A decreased uptake and cytotoxicity were observed for PEG-PC-coated multiple emulsion in vitro, compared with uncoated ones. The IC₅₀ (50% inhibitory concentrated) was also decreased 1.64 times. In vivo antitumor activity was recorded as mean survival time (MST) of mice injected intravenously or intraperitoneally with tumor cells or, treated with 6-MP formulations through similar routes. MST was increased upon treatment. The normal peritoneal cells remained unchanged while blood parameters were restored with multiple emulsion treatment to tumor-bearing mice. The efficacy of the formulation was mainly due to the slow release and effective delivery of the drug from the formulation, suggesting its potential use for the treatment of cancer.     

The effect of quercetin on the pharmacokinetics of verapamil and its major metabolite, norverapamil, in rabbits

We have investigated the effect of quercetin on the pharmacokinetics of verapamil and its major metabolite, norverapamil, in rabbits. Pharmacokinetic parameters of verapamil and norverapamil were determined after the oral administration of verapamil (10 mg kg(-1)) to rabbits in the presence and absence of quercetin (5.0 and 15 mg kg(-1)). While co-administration of quercetin concurrently was not effective to enhance the oral exposure of verapamil, pretreatment of quercetin 30 min before verapamil administration significantly altered the pharmacokinetics of verapamil. Compared with the control group (given verapamil alone), the C(max) and AUC of verapamil increased approximately twofold in the rabbits pretreated with 15 mg kg(-1) quercetin. There was no significant change in T(max) and terminal plasma half-life (t(1/2)) of verapamil in the presence of quercetin. Consequently, absolute and relative bioavailability values of verapamil in the rabbits pretreated with quercetin were significantly higher (P < 0.05) than those from the control group. Metabolite-parent AUC ratio in the rabbits pretreated with quercetin decreased by twofold compared with the control group, implying that pretreatment of quercetin could be effective to inhibit the CYP3A4-mediated metabolism of verapamil. In conclusion, pretreatment of quercetin significantly enhanced the oral exposure of verapamil. This suggested that concomitant use of quercetin or a quercetin-containing dietary supplement with verapamil requires close monitoring for potential drug interaction.     

Azathioprine metabolism: pharmacokinetics of 6-mercaptopurine, 6-thiouric acid and 6-thioguanine nucleotides in renal transplant patients

Despite extensive clinical experience with azathioprine (AZA), the disposition of various AZA metabolites remains obscure. We therefore evaluated the pharmacokinetics of three AZA metabolites: 6-mercaptopurine (6-MP), the immediate metabolite; 6-thiouric acid (6-TU), the final end product; and 6-thioguanine nucleotides (TGN), the active moiety; in eight renal transplant patients after oral administration of AZA. The low peak plasma 6-MP level of 73.7 +/- 23.7 ng/mL (mean +/- SD) and the short half-life (t1/2) of 1.9 +/- 0.6 hours suggest rapid conversion of 6-MP to other metabolites. A peak plasma 6-TU concentration of 1210 +/- 785 ng/mL was observed at 3.5 +/- 0.6 hours after the AZA dose. The strong correlation between 6-TU t1/2 and serum creatinine (r = 0.98, P = .0008) supported our previous work showing that 6-TU is primarily excreted by the kidneys. The total TGN levels in red blood cells (RBCs) in each patient remained largely unchanged over 24 hours with the intraindividual coefficient of variation ranging from 4.4% to 29.8%. In comparison, the mean TGN level varied considerably between patients, and ranged from undetectable to 413 pmol per 8 X 10(8) RBCs. However, there was no apparent correlation between white cell counts on day 0 (P greater than .5), day 7 (P greater than .5), or day 14 (P greater than .5) and RBC TGN level. The persistence of TGN in body tissues thus provides a pharmacokinetic rationale for the conventional once or twice daily AZA regimen.(ABSTRACT TRUNCATED AT 250 WORDS)