肉仔鸡静注和内服环丙沙星(ciprofloxacin)的药物动力学

16只健康 AA肉仔鸡 ,随机分成 2组 ,每组 8只 ,按 10 mg/ kg剂量分别进行静注和内服单剂量环丙沙星药动学试验。血浆中药物浓度用高效液相色谱法测定 ,血药浓度 -时间数据用 MCPKP药动学计算机程序处理。结果表明 ,静注给药后的药时数据符合无吸收二室开放模型 ,主要动力学参数分别为 :t1 /2α为 (0 .2 34± 0 .0 49) h,t1 /2β为 (10 .118±0 .2 71) h,VB为 (1.374± 0 .12 4) L/ kg,CLB为 (0 .0 94± 0 .0 0 9) L· kg- 1 · h- 1 ,AUC为 (10 7.0 6 8± 10 .6 40 ) mg· L- 1· h。内服给药后的药时数据符合一级吸收一室开放模型 ,主要动力学参数分别为 :t1 /2 kα为 (0 .114± 0 .0 0 8) h,t1 /2 k为(7.784± 0 .5 14) h,Tp 为 (0 .70 2± 0 .0 31) h,Cmax为 (5 .736± 0 .5 15 ) m g/ L,AUC为 (6 8.6 2 2± 8.147) mg· L- 1· h,F为 (6 4.0 92± 7.6 10 ) %。肉仔鸡静注环丙沙星在其体内消除较慢 ,分布广泛 ;内服给药吸收迅速 ,消除较静注给药快。     

Comparative Pharmacokinetics and Bioavailability of Amoxycillin in Chickens after Intravenous,Intramuscular and Oral Administrations

The pharmacokinetics and systemic bioavailability of amoxycillin were investigated in clinically healthy, broiler chickens (n = 10 per group) after single intravenous (i.v.), intramuscular (i.m.), and oral administrations at a dose of 10 mg/kg body weight. The plasma concentrations of amoxycillin were determined using high-performance liquid chromatography (HPLC) and the data were subjected to compartmental and non-compartmental kinetic analyses. Following single i.v. injection, all plasma amoxycillin data were described by a two compartment-open model. The elimination half-lives of amoxycillin were 1.07 h, 1.09 h and 1.13 h after single i.v., i.m. and oral administration, respectively. The total body clearance (Cl(B)) of amoxycillin was 0.80 (L/h)/kg and the volume of distribution calculated as V(d(area)) was 1.12 L/kg, respectively after i.v. administration. Substantial differences in the resultant kinetic data were obtained by comparing the plasma concentration profiles after i.m. injection with that after oral administration. The systemic i.m. bioavailability of amoxycillin was higher (77.21%) than after oral (60.92%) dosing. In vitro, the mean plasma protein binding of amoxycillin amounted to 8.27%. Owing to high clearance of amoxycillin in birds in our study, a plasma level was maintained above 0.25 microg/ml for only 6 h after i.m. and oral routes of administration and consequently frequent dosing may be necessary daily.     

Flumequine in the Goat: Pharmacokinetics after Intravenous and Intramuscular Administration

The pharmacokinetics of flumequine, administered intravenously and intramuscularly at a single dose of 20 mg/kg, was investigated in healthy goats. After intravenous injection, flumequine distributed rapidly (t1/2alpha = 0.87+/-0.15 h) but was eliminated slowly (t1/2beta = 7.12+/-1.27 h); mean clearance (Cl) and volume of distribution (Vdss) were 0.32+/-0.03 (L/(h x kg) and 1.22+/-029 (L/kg), respectively. After intramuscular administration, the peakserum concentration (Cmax = 7.40+/-0.5 microg/ml) was reached in about 1.5 h (Tmax) and bioavailability was about 93%. Estimated flumequine serum levels following repeated intramuscular administration of the aqueous suspension used in the study (7.23+/-0.7 microg/ml and 4.82+/-0.47 microg/ml at intervals of 8 and 12 h, respectively) indicated that to maintain serum levels above MIC values for susceptible bacteria a dosage regimen of 20 mg/kg every 12 h is necessary by the intramuscular route.     

Disposition Kinetics of Difloxacin After Intravenous,Intramuscular and Subcutaneous Administration in Calves

The pharmacokinetics of difloxacin (Dicural) was studied in a crossover study using three groups (n = 4) of male and female Friesian calves after intravenous (i.v.), intramuscular (i.m.) and subcutaneous (s.c.) administrations of 5 mg/kg body weight. Drug concentration in plasma was determined by high-performance liquid chromatography using fluorescence detection. The plasma concentration–time data following i.v. administration were best fitted to a two-compartment open model and those following i.m. and s.c. routes were best fitted using one-compartment open model. The collected data were subjected to a computerized kinetic analysis. The mean i.v., i.m. and s.c. elimination half-lives (t _1/2β) were 5.56 ± 0.33 h, 6.12 ± 0.42 h and 7.26 ± 0.6 h, respectively. The steady-state volume of distribution (V _dss) was 1.12 ± 0.09 L/kg and total body clearance (Cl_B) was 2.19 ± 0.1 ml/(min. kg). The absorption half lives (t _1/2ab) were 0.38 ± 0.027 h and 2.1 ± 0.09 h, with systemic bioavailabilities (F) of 96.5% ± 6.4% and 84% ± 5.5% after i.m. and s.c. administration, respectively. After i.m. and s.c. dosing, peak plasma concentrations (C _max) of 3.38 ± 0.13 μg/ml and 2.18 ± 0.12 μg/ml were attained after (t _max) 1.22 ± 0.20 h and 3.7 ± 0.52 h. The MIC₉₀ of difloxacin for Mannheimia haemolytica was 0.29 ± 0.04 μg/ml. The AUC/MIC₉₀ and C _max/MIC₉₀ ratios for difloxacin following i.m. administration were 120 and 11.65, respectively and following s.c. administration were 97.58 and 7.51, respectively. Difloxacin was 31.7–36.8% bound to calf plasma protein. Since fluoroquinolones display concentration-dependent activities, the doses of difloxacin used in this study are likely to involve better pharmacodynamic characteristics that are associated with greater clinical efficacy following i.m. administration than following s.c. administration.     

Pharmacokinetics of Ricobendazole After its Intravenous,Intraruminal and Subcutaneous Administration in Sheep

Ricobendazole (RBZ) was administered in sheep at the dose rate of 5 mg/kg by intravenous (i.v.) route as a 10% experimental solution, by the intraruminal (i.r.) route as a 10% experimental suspension, and by the subcutaneous (s.c.) route as a 10% commercial formulation available in Argentina. Blood samples were drawn during a 60 h period. Plasma concentrations of RBZ and its inactive metabolite albendazole sulphone (ABZSO₂) were determined by high-performance liquid chromatography. The pharmacokinetic parameters were determined by compartmental analysis. The fitting of the data was done by weighted least-squares non-linear regression analysis. The pharmacokinetic parameters were estimated for every animal by simultaneous fitting of the plasma concentrations profiles of RBZ obtained after its administration by the three routes. The kinetic analysis of ABZSO₂ was performed by a statistical moment approach. Ricobendazole bioavailability was poor after i.r. administration, whereas high and sustained plasma concentrations and higher bioavailability were obtained after s.c. administration. A simple two-compartment open model explains in a mechanical sense the pharmacokinetic behaviour of RBZ in sheep and allows us to estimate the real first-order constant rate of absorption and the loss of drug from the absorption site after its administration by s.c. and i.r. routes.     

黄牛静注、肌注和内服吡喹酮的药动学与生物利用度

6头成年健康黄牛按10 mg/kg剂量单次快速静注吡喹酮,另6头成年健康黄牛根据交叉试验设计法按10 mg/kg剂量单次肌注、30 mg/kg剂量内服吡喹酮进行药动学与生物利用度试验.利用高效液相色谱法测定血浆中吡喹酮原药的质量浓度,其检测限为25μg/L.房室模型分析表明,静注给药后的药时数据符合无吸收二室开放模型,其分布半衰期(t1/2a)、消除半衰期(t1/2β)、表观分布容积(Vd)、总体清除率(ClB)、药时曲线下面积(AUC)分别为(0.25±0.03)h、(1.28±0.20)h、(2.11±0.38)L/kg、(1.14±0.10)L/(kg·h)和(8.79±0.74)mg/(L·h).肌注的药时数据符合有吸收一室开放模型,主要药动学参数吸收半衰期(t 1/2ka)、消除半衰期(t1/2ke)、药时曲线下面积(AUC)、达峰时间(tmax)、峰浓度(Gmax)和生物利用度(F)分别为(0.40±0.17)h、(4.65±0.91) h、(6.85±1.02)mg/(L·h)、(1.33±0.52)h、(0.83±0.08)mg/L和77.93%.内服给药后符合有吸收一室开放模型,吸收不规则,其药动学参数t 1/2ka、t1/2ke、AUC、tmax、Cmax和F分别为(1.08±0.13)h、(6.81±1.26)h、(8.51±1.78)mg/(L·     

Pharmacokinetics of Tilmicosin (Provitil Powder and Pulmotil Liquid AC) Oral Formulations in Chickens

A bioavailability and pharmacokinetics study of powder and liquid tilmicosin formulations was carried out in 18 healthy chickens according to a single-dose, two-period, two-sequence, crossover randomized design. The two formulations were Provitil and Pulmotil AC. Both drugs were administered to each chicken after an overnight fast on two treatment days separated by a 2-week washout period. A modified rapid and sensitive HPLC method was used for determination of tilmicosin concentrations in chicken plasma. Various pharmacokinetic parameters including area under plasma concentration–time curve (AUC₀₋₇₂), maximum plasma concentration (C _max), time to peak concentration (t _max), elimination half-life (t _1/2β), elimination rate (k _el), clearance (Cl_B), mean residence time (MRT) and volume of distribution (V _d,area) were determined for both formulations. The average means of AUC₀₋₇₂ for Provitil and Pulmotil AC were very close (24.24 ± 3.86, 21.82 ± 3.14 (μg.h)/ml, respectively), with no significant differences based on ANOVA. The relative bioavailability of Provitil as compared to Pulmotil AC was 111%. In addition, there were no significant differences in the C _max (2.09 ± 0.37, 2.12 ± 0.40 μg/ml), t _max (3.99 ± 0.84, 5.82 ± 1.04 h), t _1/2β (47.4 ± 9.32, 45.0 ± 5.73 h), k _el (0.021 ± 0.0037, 0.022 ± 0.0038 h⁻¹), Cl_B (19.73 ± 3.73, 21.37 ± 4.54 ml/(min/kg)), MRT (71.20 ± 12.87, 67.15 ± 9.01 h) and V _d,area (1024.8 ± 87.5, 1009.8 ± 79.5 ml/kg) between Pulmotil AC and Provitil, respectively. In conclusion, tilmicosin was rapidly absorbed and slowly eliminated after oral administration of single dose of tilmicosin aqueous and powder formulations. Provitil and Pulmotil AC can be used as interchangeable therapeutic agents.     

肌注硫酸庆大霉素在大肠杆菌感染鸡体内的药动学试验

为分析硫酸庆大霉素在健康和鸡大肠杆菌感染鸡体内的药物动力学特征,试验通过给健康鸡腹腔注射大肠杆菌O157,以临床症状、病理剖检和微生物检查为指标,成功建立鸡大肠杆菌感染模型。选取健康鸡和患病鸡各8只,分别以20 mg/kg体重单剂量肌内注射硫酸庆大霉素,分别于0.167、0.25、0.5、0.75、1、2、3、4、6、8和12 h时间点采血,采用管碟法测定血浆中庆大霉素的浓度。结果显示:试验所建立的标准曲线相关性好,相关系数均达0.990以上,日内、日间变异系数均小于10%。肌注给药后,硫酸庆大霉素在鸡体内吸收迅速,房室模型分析表明,健康鸡与患病鸡药时数据均符合有二室开放模型,硫酸庆大霉素在健康鸡体内峰浓度(Cmax)为(15.01±3.51)μg/mL,药时曲线下面积(AUC)为(100.79±5.14)μg/mL·h,消除半衰期(t1/2β)为(4.41±1.32)h,达峰时间(Tp)为(1.27±0.50)h。硫酸庆大霉素在患病鸡体内峰浓度(Cmax)为(12.50±2.19)μg/mL,药时曲线下面积(AUC)为(83.38±4.19)μg/mL·h,消除半衰期(t1/2β)为(4.18±1.17)h,达峰时间(Tp)为(0.97±0.05)h。结果表明:硫酸庆大霉素在患病鸡体内的峰浓度和药时曲线下面积低于健康鸡(P<0.05),因此对于已感染大肠杆菌的病鸡可以考虑适当增加给药剂量。     

Pharmacokinetics of Pefloxacin in Goats after Intravenous or Oral Administration

The plasma concentrations and pharmacokinetics of the fluoroquinolone antimicrobial agent pefloxacin, following the administration of a single intravenous (10 mg/kg) or oral (20 mg/kg) dose, were investigated in healthy female goats. The antimicrobial activity in plasma was measured at predetermined times after drug administration by an agar well diffusion microbiological assay, using Escherichia coli (ATCC 25922) as the test organism. Concentrations of the drug 0.25 g/ml were maintained in plasma for up to 6 and 10 h after intravenous (IV) or oral administration of pefloxacin, respectively. The concentration–time data for pefloxacin in plasma after IV or oral administration conformed to two- and one-compartment open models, respectively. Plasma pefloxacin concentrations decreased rapidly during the initial phase after IV injection, with a distribution half-life (t _1/2 ) of 0.10±0.01 h. The terminal phase had a half-life (t _1/2 ) of 1.12±0.21 h. The volume of distribution at steady state (V _dss), mean residence time (MRT) and total systemic clearance (Cl_B) of pefloxacin were 1.08±0.09 L/kg, 1.39±0.23 h and 821±88 (ml/h)/kg, respectively. Following oral administration of pefloxacin, the maximum concentration in the plasma (C _max) was 2.22±0.48 g/ml and the interval from administration until maximum concentration (t _max) was 2.3±0.7 h. The absorption half-life (t _{1/2 ka}), mean absorption time (MAT) and elimination half-life of pefloxacin were 0.82±0.40, 4.2±1.0 and 2.91±0.50 h, respectively. The oral bioavailability of pefloxacin was 42%±5.8%. On the basis of the pharmacokinetic data, a dosage regimen of 20 mg/kg, IV at 8 h intervals or orally twice daily, is suggested for treating infections caused by drug-sensitive pathogens in goats.     

肌内注射后氟苯尼考在肉鸡体内生理药动学模型血流图模拟设计

根据氟苯尼考在肉鸡体内的药动学特征及肉鸡的生理学、解剖学特点,设计了一个包含氟苯尼考及氟苯尼考胺两部分在内的生理药动学模型血流图。模拟肌内注射给药后药物的吸收、分布、肝脏代谢及肝肠循环等过程。为氟苯尼考及氟苯尼考胺在肉鸡体内PBPK模型的最终建立提供了思考路径。     

口服亚硒酸钠在肉鸡体内药代动力学的研究

实验研究了30日龄肉鸡单次口服（0．6mg／kg）亚硒酸钠注射液后不同时间采血,用流动注射氢化物发生原子吸收光谱法测定血硒浓度,经微机处理得出血硒浓度及药动学参数,血硒浓度一时间曲线符合一级吸收一室开放模型,最佳药时方程：C-100．2001（e-9·0197t—e-6428‘）。主要药动学参数：（1／2Ka为0．4219h,t1／2Ke为35．1215h,t。为3．3124h,Cmax为93．9865tLg／L,AUC为5025．3149％g／L）·h。根据单剂量给药参数,计算出多剂量给药参数。     

国产表阿佛菌素在绵羊体内的药代动力学研究

用反相高效液相色谱结合荧光检测法,对试验绵羊经静脉、皮下单剂量注射0 2 mg/kg表阿佛菌素的药代动力学进行了研究。血样提取物通过C18小柱富集、洗脱,甲醇洗提部分经加入1 甲基咪唑和三氟乙酸酐的乙腈液衍生化后进行色谱分析。血药浓度在 2. 5 ~ 200 ng/mL 范围呈良好线性关系(R= 0 996 8),方法平均回收率96 65%±3.84%,血药最低检测限 2.5 ng/mL,日内、日间变异系数分别小于 10%、12%。2 种途径给药后体内药物运转分别符合二室和一室开放模型。主要药代参数如下,静脉注射:消除半衰期(T1/2β)12.66±2.05 h,药时曲线下面积(AUC0~74)1.02±0 30 (mg/L)·h,fc=0 13±0 05; 皮下注射:吸收半衰期(T1/2ka )4.42±1.04 h,峰浓度(Cmax)0 02±0 01 μg/mL,峰时(Tmax ) 15. 36±2. 91 h,消除半衰期(t1/2k ) 26. 22±9. 04 h,药时曲线下面积(AUC0~122)1.19±0 37 (mg/L)·h。上述结果表明,绵羊静脉注射表阿佛菌素后体内药物分布广泛,消除较慢。皮下注射吸收好,消除比静脉注射更为缓慢,体内药物平均滞留时间长。     

Pharmacokinetics of Sulpiride After Intravenous,Intramuscular, and Oral Single-Dose Administration in Nurse Mares

Sulpiride (SLP) is an antipsychotic drug used in humans. Although no pharmacokinetic data are available for horses, it is commonly used to encourage ovulation in noncycling mares and to stimulate lactation in adoptive mares. The aim of this study is to assess the pharmacokinetics profile of SLP after intravenous (IV), intramuscular (IM), and oral (PO) administrations in normal horses. Animals (n = 6) were treated with 1 mg/kg SLP, administered by IV, IM, and PO routes according to a randomized crossover design (3 × 3 Latin square). Blood samples (5 mL) were collected at a programmed time and analyzed using a validated with fluorescence detection method. SLP was present at a detectable concentration up to 24 hours postadministration for all routes, except for one animal in the PO group. IV and IM administrations gave similar curves, with an IM average bioavailability of 118.0%. These high values were mainly the result of the profile generated by two horses, in which a secondary concentration peak occurred in the terminal phase of the curve. After PO administration, AUC_0-∞, and consequently bioavailability (20.4%), was low. This finding could be owing to the physicochemical features of the drug. Indeed, considering that SLP is a weak base, existing in the ionized form at gastric and physiological pH, it is unsurprising that it is poorly absorbable, especially in horses with a particularly acidic gastric pH. In conclusion, injective routes are definitely preferable to PO dosing because of the low bioavailability using this route.     

桔梗对左氧氟沙星在健康鸡体内药动学影响的研究

为研究桔梗对左氧氟沙星（LVLX）在健康鸡体内的血药浓度及药动学参数的影响，72只健康鸡随机平均分成2组，Ⅰ组单剂量灌胃给予左氧氟沙星（10mg／kg）；Ⅱ组左氧氟沙星（10mg／kg）与桔梗煎液（2g／kg）联用。采用高效液相色谱法测定血药浓度，最低检测限0．001mg／L，并以3P97药动学程序进行分析，药时数据均符合一级吸收二室模型（权重=1）。与Ⅰ组相比，Ⅱ组的药动学参数有如下变化：T1/2α、T1/2ka增大，Cmax、ka降低，差异均不显著（P〉0．05）；T1/2β、Tmax、AUC、MRT0-36均极显著增加（P〈0．01）。结果表明：桔梗对左氧氟沙星在健康鸡体内的药物代谢有较大影响；减慢LVLX在体内的吸收速度，但增加了LVLX吸收的程度；加快了LVLX向组织的转运；减慢了LVLX在鸡体内的消除速度，延长了药物在体内的作用时间。     

Bioavailability and Pharmacokinetics of Sulphadiazine,N<Superscript>4</Superscript>-acetylsulphadiazine and Trimethoprim following Intravenous and Intramuscular Administration of a Sulphadiazine/Trimethoprim Combination in Sheep

The combination of sulphadiazine and trimethoprim is extensively used in farm animal species; however, there are no data concerning its pharmacokinetics after intramuscular administration in sheep. Twelve rams of the Chios breed were used to study the disposition of sulphadiazine, its metabolite N⁴-acetylsulphadiazine and trimethoprim after intravenous (i.v.) and intramuscular (i.m.) administration of a sulphadiazine/trimethoprim (5:1) combination in sheep. Sulphadiazine bioavailability (±SD) was 69.00%±10.51%. The half-life of the terminal phase (4.10±0.58 h afteri. v., and 4.03±0.31 h after i.m. administration) was significantly higher than the respective value for trimethoprim (0.59±0.19 h) afteri.v. administration. The maintenance of a constant plasma concentration ratio after i.v. administration was therefore impossible. The acetylation capacity in sheep, determined by the AUC ratio between N⁴-acetylsulphadiazine and the parent compound, sulphadiazine, was very low (less than 4%). The most remarkable finding of this study was that trimethoprim was not detected in sheep plasma after i.m. injection. In conclusion, according to the findings of the present study, following i.v. administration of the sulphadiazine/trimethoprim combination, trimethoprim can be considered as the limiting factor for any possible synergistic effect, and the i.m. route cannot be recommended in sheep.     

麻保沙星(marbofloxacin)在鸡体内的生物利用度及药物动力学

选用 36只 5 1～ 6 0日龄健康岭南黄鸡 ,随机均分为 3组 ,对静注、肌注及内服麻保沙星 (2 .5 mg/ kg)的生物利用度和药物动力学进行了研究。用三氯甲烷提取血浆中的药物 ,反相高效液相色谱法测定血浆中麻保沙星的浓度 ,MCPKP计算机程序处理所得到的血药浓度 -时间数据。静注给药的药时数据适合三室开放模型 ,主要药动学参数分别为 :t1 /2π(0 .19± 0 .0 3) h;t1 /2α(2 .0 7± 0 .2 7) h;t1 /2β(6 .5 2± 0 .6 9) h;V1 (0 .48± 0 .0 3) L / kg;Vd(area) (2 .0 6± 0 .39)L/ kg;Vd(ss) (1.0 5± 0 .0 6 ) L/ kg;Cl B(0 .19± 0 .0 2 ) L/ (kg· h) ;AUC(13.95± 1.0 7) mg· kg- 1 · h。肌注给药的药时数据适合一级吸收二室开放模型 ,主要药动学参数分别为 :t1 /2 Ka(0 .5 4± 0 .0 5 ) h;t1 /2α(2 .33± 0 .2 0 ) h;t1 /2β(6 .2 7± 0 .46 )h;tmax(1.5 7± 0 .0 9) h;Cmax(1.88± 0 .0 5 ) m g/ L ;AUC(13.18± 0 .6 7) mg· kg- 1 · h;F(94.45± 4.80 ) %。内服给药的药时数据适合一级吸收二室开放模型 ,主要药动学参数分别为 :t1 /2 Ka(0 .42± 0 .0 6 ) h;t1 /2α(2 .31± 0 .2 5 ) h;t1 /2β(6 .48±0 .6 6 ) h;tmax(1.35± 0 .12 ) h;Cmax(1.83± 0 .18) mg/ L;AUC(13.5 5± 0 .6 7) mg· k     

盐酸沙拉沙星(sarafloxacin)在鸡体内的药动学和生物利用度

2组健康艾维因肉鸡各 8只 ,体重 (1.6 6± 0 .11) kg,研究了对其单剂量 (10 mg/kg,以沙拉沙星碱计 )静注和口服盐酸沙拉沙星后的药动学及其生物利用度 ,用高效液相色谱法测定血清中沙拉沙星的浓度。结果表明 :静注盐酸沙拉沙星溶液后 ,血清药物浓度经时过程符合无吸收因素二室模型 ,其消除半衰期 (t1 / 2β)、总体清除率 (CLB)、表观分布容积 (Vd)和药时曲线下面积 (AU C)分别为 (2 .6 78± 0 .5 0 6 ) h、(1.339± 0 .35 1) L/kg· h、(5 .15 9± 1.5 5 4) L/kg和(7.85 3± 1.731) mg/L· h;口服盐酸沙拉沙星片后 ,药时数据呈有吸收因素一室模型 ,其吸收和消除半衰期 (t1 / 2 ka,t1 / 2 ke)、血清峰浓度 (Cmax)、达峰时间 (Tmax)和药时曲线下面积 (AUC)分别为 (0 .2 87± 0 .117) h、(5 .381± 1.44 6 ) h、(0 .478± 0 .196 ) mg/L、(1.2 2 9± 0 .439) h和 (4 .0 6 0± 1.178) m g/L· h,生物利用度为 (5 1.70± 15 .0 0 ) %。     

Influence of Fluid Therapy on Gentamicin Pharmacokinetics in Colic Horses

The aminoglycoside antibiotic gentamicin is commonly used in equine medicine for the prevention and treatment of Gram-negative and staphylococcal bacteria in surgically treated colic patients. The pharmacokinetics of gentamicin in these patients might be altered by the disease status, and/or under the influence of fluid therapy. The purpose of this study was to investigate the effect of intravenous fluid treatment on gentamicin kinetics in colic patients. Colic patients subjected to laparotomy were given fluid infusions according to clinical status. Following gentamicin administration, blood samples were taken for gentamicin analysis at different time points, and the main pharmacokinetic parameters including Vc, Vss, t(1/2) and MRT were calculated. Horses undergoing fluid therapy showed a significantly different t(1/2), clearance and MRT as compared to non-infused patients. However, taking into account the clinical status of the patients receiving fluid support, the data suggest that endotoxaemia, rather than fluid therapy, influence gentamicin pharmacokinetics following laparotomy.     

猪内服和静脉给予多西环素的药代动力学研究

建立了超高效液相色谱-串联质谱法测定猪血浆中多西环素的浓度,探讨了猪内服和静脉给予多西环素水溶液后的药代动力学特征。结果表明：猪单次内服10 mg.kg_-1体重多西环素饮水剂型水溶液后,MRT_last为12.82±3.34 h,T_1/2为11.65±4.80 h,Tmax为4.13±1.89 h,Cmax为0.87±0.48 μg.mL_-1,AUC_last为11.07±4.19μg.h.mL_-1。猪静注10 mg.kg_-1体重多西环素水溶液后,AUC_last为33.34±8.03μg.h.mL_-1,T_1/2为5.68±1.32 h,MRT_last为7.98±0.56 h。多西环素饮水剂水溶液的绝对生物利用度为33.2%。猪内服多西环素饮水剂后,具有体内吸收速度较快,达峰时间短,消除较慢,血中平均滞留时间较长等特点。