多拉菌素在猪体内的药代动力学

对多拉菌素在猪体内进行为期45d的药代动力学研究。长白×杜洛克杂交猪10头,临床健康,驱净寄生虫,体重36～50kg,以300μg/kg体重剂量分别通过静脉和肌肉注射给药。动物给药后在不同时间内分点经颈静脉采血。血浆样品用乙腈沉淀处理,上清液过C18富集柱,用甲醇提取多拉菌素并进行衍生化反应,以反向HPLC测定猪血清中的药物浓度。药代动力学参数用计算机程序MCPKP进行处理。结果表明,动物经静脉和肌肉注射给药后,血浆药物浓度分别可测至30d和25d,2种途径的药物浓度时间曲线均符合二室开放模型。主要药代动力学参数为:静脉注射T1/2α(1.092±0.66)d,T1/2β(6.11±2.73)d,AUC(274.19±119.89)μg/(L·d);肌肉注射T1/2α(0.056±0.022)d,T1/2β(3.20±1.34)d,AUC(223.51±65.20)μg/(L·d),CMAX(28.99±10.69)μg/L,Tp(1.24±0.87)d。多拉菌素肌肉注射的生物利用度为81.5%。结果显示多拉菌素在猪体内具有吸收分布较迅速、体内分布容积大、消除缓慢和生物利用度相对较高的特点,提示多拉菌素在猪体内作用的长效性主要由该化合物的自身特性所决定,而与给药途径和使用的溶剂关系不大,研究结果对指导临床正确用药具有重要意义。     

多拉菌素驱除猪体内线虫试验

选取 8 0头仔猪进行驱除体内线虫试验 ,试验分 5组进行 (多拉菌素高、中、低剂量组、伊维菌素对照组及空白对照组 )。通过试验前后寄生虫感染情况的比较 ,表明多拉菌素驱除猪寄生线虫效果确实、可靠 ,其中高剂量组和中剂量组药物残效期达 2 8d。推荐使用中剂量即 3 0 0 μg/kg体重     

多拉菌素治疗猪蛔虫病的疗效观察

将自然感染猪蛔虫的15头猪,随机分为5组,即多拉菌素高、中、低剂量组,伊维菌素对照组和空白对照组。多拉菌素驱杀猪蛔虫效果明显,且具有吸收分布快、消除缓慢和生物利用度高的特点。多拉菌素驱杀猪蛔虫效果确实可靠,其中高剂量和中剂量组更为显著,临床推荐剂量以300μg／kg体重为宜。     

多拉菌素在治疗猪寄生虫上的应用

多拉菌素为新一代大环内酯类抗寄生虫药,与其它市售的伊维菌素类产品比较,其抗寄生虫范围更广泛、效果更好,而且预防寄生虫再感染的有效时间更长,是目前世界上效果最好、最有开发潜力的兽用抗寄生虫新药。     

猪肌肉注射两种恩诺沙星注射液的药物动力学比较

选用6头健康杂种猪,随机交叉设计试验,进行肌注两种不同pH的恩诺沙星注射液(2.5 mg/kg)的药物动力学比较的研究.反相高效液相色谱法测定血浆中恩诺沙星的浓度.所得血药浓度-时间数据用MCPKP计算机程序处理.pH10.3及pH8.3的恩诺沙星注射液肌注给药的药时数据适合-级吸收一室模型,主要药物动力学参数分别是t1/2ka0.25±0.28 h及0.14±0.05 h;t1/2ke4.54±0.63及4.64±0.84 h;tmax0.95±0.70 h及0.69±0.23 h;Cmax0.96±0.16及0.92±0.29;AUC 7.58±1.10μg/ml·h及6.59±1.50μg/ml·h.两者的药物动力学参数无显著性差异(P＞0.05).     

多拉菌素浇泼剂在犬体内的药代动力学

本试验对多拉菌素浇泼剂在犬血浆中的药代动力学进行了研究。犬背部皮肤一次浇注多拉菌素浇泼剂(0.1 mg/kg体重),给药后,不同时间点从犬前肢静脉采血。以高效液相色谱法对血浆中药物浓度进行测定,血浆药物浓度—时间数据用WinNonlin 5.2.1的非房室模型药动软件处理。给药后的主要药物动力学参数为:t1/2β为(2.14±0.56)d,T_max为(1.00±0.00) d,C_max为(24.38±4.82) ng/mL,AUC为(89.79±16.90)ng/(d·mL)。提示多拉菌素浇泼剂在犬体内血药浓度维持的时间较长,消除缓慢。     

多拉菌素对猪寄生虫病的驱虫效果观察

比较不同来源的多拉菌素对猪消化道线虫和体表寄生虫的驱杀效果,为临床应用该药提供科学依据。将自然感染寄生虫的猪,随机分为高、中、低3个剂量的药物试验组和不给药物治疗对照组,健康无寄生虫感染的猪作为对照,根据试验前和试验后7、14、28、35 d猪寄生虫数量和临床变化判定疗效。结果显示,海正多拉与辉瑞通灭对猪的体表寄生虫及消化道线虫均有极好的驱杀作用,临床推荐剂量以中剂量组300μg/kg·BW肌肉注射为宜。     

多拉菌素的研究进展

从多拉菌素的理化性质、药代动力学、药效学、毒理学及其对机体免疫力影响、药物制剂和残留检测等几个方面,阐述了多拉菌素作为一种优良的抗寄生虫药物,具有安全、广谱、高效、长效和奶中残留低等特点,为临床合理用药提供指导。     

多拉菌素在猪粪便中的残留消除规律研究

阿维菌素类药物(A verm ectins,AVM s)属于16元大环内酯类抗生素,对动物的线虫、节肢动物均有强大的抑杀作用,因其极低的给药剂量即可获得良好的药效,现已在许多国家广泛用于治疗或控制各类哺乳动物的寄生虫病。多拉菌素(25-环己基阿维菌素,Doram ectin,DOR)为阿维菌素家族中的     

多拉菌素的应用研究进展

多拉菌素是阿维菌素的第三代衍生物，截至目前，这一药物被公认为是阿维菌素族中效果最优秀的既驱除体内寄生虫又驱除体外寄生虫的有效药物，多拉菌素不但对体内线虫具有非常好的驱杀效果，同时对体外的节肢动物体也具有很好的驱除作用。为了能够更全面深入地了解多拉菌素，文章从多拉菌素的理化性质、应用以及展望等几个方面进行了阐述，以期能够为临床合理用药提供理论依据。     

牦牛肺炎的病理学观察和细菌学初步诊断

对2002年陕西省凤县的病死牦牛进行了常规病理学检查,尸体剖检发现大脑、心脏、肺脏、肝脏、消化道、肾脏等器官均发生了不同程度的病变。进一步的组织病理学观察发现,肺组织充血,肝组织淋巴细胞浸润,肝细胞颗粒变性等。细菌学诊断分离到了致病性的巴氏杆菌和葡萄球菌。提示该病可能是巴氏杆菌感染引起,人工感染模型有待进一步研究。     

恩诺沙星长效注射液肌注后在猪体内的药动学研究

研究了恩诺沙星长效注射液给猪肌注后的药物动力学特征。将12只白猪随机分成两组,每组6只,分别肌注恩诺沙星注射液(5mg/kg)和长效恩诺沙星注射液(18.75mg/kg),并于给药后0.1, 0.25, 0.5, 1, 2, 4, 8, 12, 24, 36, 48, 60h, 从前腔静脉采取5ml血,用HPLC分析各血浆样品中的药物浓度,用MCPKP软件计算药动学参数。结果表明:长效恩诺沙星注射液肌注后,经5.64h达到4.86μg/ml的最高浓度,吸收半衰期和消除半衰期分别为2.42h和19.47h,有效浓度维持时间为128.73h, AUC为166.96mg/L.h。吸收半衰期显著延长(p<0.05),达峰时间极显著推迟(p<0.01),消除半衰期也显著长于恩诺沙星注射液。     

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.     

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 and Dosage Regimen of Enrofloxacin in Buffalo Bulls after Intramuscular Administration

The disposition kinetics and dosage regimen of enrofloxacin were investigated in breeding buffalo bulls following a single intramuscular administration of 5 mg/kg. The absorption half-life, half-life of the terminal phase, apparent volume of distribution and total body clearance were 0.262±0.099 h, 1.97±0.23 h, 0.61±0.13 L/kg and 210.2±18.6 ml/(kg.h), respectively. Therapeutic plasma levels (1 g/ml) were maintained for up to 6 h. A satisfactory intramuscular dosage regimen for enrofloxacin in buffalo bulls would be 8.5 mg/kg followed by 8.0 mg/kg at 8 h intervals.     

Pharmacokinetics of Enrofloxacin and Its Metabolite Ciprofloxacin after Intramuscular Administration of Enrofloxacin in Goats

The pharmacokinetics of enrofloxacin and its active metabolite ciprofloxacin were investigated in goats after a single intramuscular administration of enrofloxacin at 2.5 mg/kg body weight. The plasma concentrations of enrofloxacin and ciprofloxacin were determined simultaneously by a HPLC method. The peak concentrations (C _max) of enrofloxacin (1.13 g/ml) and ciprofloxacin (0.24 g/ml) were observed at 0.8 and 1.2 h, respectively. The elimination half-life (t _1/2), volume of distribution (V _d(area)), total body clearance (Cl_B) and mean residence time (MRT) of enrofloxacin were 0.74 h, 1.42 L/kg, 1329 ml/h per kg and 1.54 h, respectively. The t _1/2, area under the plasma concentration–time curve (AUC) and the MRT of ciprofloxacin were 1.38 h, 0.74 g h/ml and 2.73 h, respectively. The metabolic conversion of enrofloxacin to ciprofloxacin was appreciable (36%) and the sum of the plasma concentrations of enrofloxacin and ciprofloxacin was maintained at or above 0.1 g/ml for up to 4 h. Enrofloxacin appears to be useful for the treatment of goat diseases associated with pathogens sensitive to this drug.     

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.