首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 203 毫秒
1.
(1.西安市未央区动物疾病预防控制中心,陕西西安710016;2.西北农林科技大学动物医学院,陕西杨凌712100;)为观察中兽药制剂丹参酮乳房注入剂与头孢噻呋联合用药对奶牛乳房炎的临床疗效,选用陕西省某奶牛标准示范基地15头患有乳房炎的奶牛,随机分为丹参酮组、头孢噻呋组、丹参酮及头孢噻呋联合用药组,每组5头,每天对奶牛感染乳室灌注药物,2次/d(早晚各1次),7 d为一疗程,进行乳样体细胞计数及临床治疗效果观察。结果显示,与用药前相比,3个组均可显著降低乳样体细胞数(P0.01);各组之间,联合用药组、头孢噻呋组均与丹参酮组之间体细胞数存在极显著差异(P0.01),联合用药组的体细胞数与头孢噻呋组间存在显著差异(P0.05);丹参酮组治愈率为0,头孢噻呋组治愈率为73.3%,联合用药组治愈奶牛临床性乳房炎治愈率可达83.3%。结果表明,丹参酮与头孢噻呋联合用药治疗奶牛乳房炎有明显的临床疗效,两者具有良好的协同作用。  相似文献   

2.
为探讨利福昔明悬乳剂灌注泌乳期奶牛乳房后在奶牛乳区的分布情况,进行了奶牛牛乳和血液中药物的药代动力学研究。试验选取6头荷斯坦奶牛,每头奶牛随机选择2个乳区,以每个乳区200 mg的剂量进行单次乳房灌注利福昔明悬乳剂,利用高效液相色谱法检测牛乳与血液中利福昔明的含量。结果表明:利福昔明悬乳剂采用单次乳房灌注给药后,给药乳区36 h内乳头中利福昔明的浓度都在2μg/mL以上,且血液中未检出利福昔明。说明药物主要集中在给药乳区,进入体循环的量极少,并且能在较长时间内具有抑菌作用。  相似文献   

3.
本试验进行了盐酸头孢噻呋乳房注入剂(干乳期)治疗奶牛干乳期乳房炎的临床疗效观察。试验选择75头即将进入干乳期且体细胞数在40万~80万个/mL的奶牛,分为5组进行临床疗效观察。结果显示,按照临床推荐剂量每个乳区注入1支(含500mg头孢噻呋)盐酸头孢噻呋乳房注入剂,对由乳房内链球菌、金黄色葡萄球菌、大肠杆菌等细菌引起的奶牛乳房炎具有良好的治疗作用。  相似文献   

4.
头孢喹诺对几种常见动物病原菌的体外抗菌作用   总被引：2，自引：0，他引：2  
采用微量肉汤稀释法测定国产头孢喹诺对5种常见动物病原菌的最小抑菌浓度(MIC),并与头孢噻呋、氨苄西林及环丙沙星进行比较。结果显示头孢喹诺对金黄色葡萄球菌的MIC为1~2μg/mL,抗菌活性强于其他3种药物;对大肠杆菌的MIC≤0.031~0.25μg/mL,抗菌活性与环丙沙星相近,高于头孢噻呋和氨苄西林;对链球菌的MIC≤0.031~1μg/mL,抗菌活性与头孢噻呋和氨苄西林相近,高于环丙沙星;对多杀性巴氏杆菌以及胸膜肺炎放线杆菌的MIC分别≤0.031~0.5μg/mL和≤0.031μg/mL,抗菌活性与头孢噻呋和环丙沙星相近,强于氨苄西林。结果表明头孢喹诺对革兰氏阳性和阴性菌均具有强大的体外抗菌作用。  相似文献   

5.
为了比较美国盐酸头孢噻呋、中国大中农盐酸头孢噻呋与中国山东某生物科技公司新研制的盐酸头孢噻呋三种头孢噻呋注射液在白羽鸡血浆中的药物代谢动力学特征,以检测新研制盐酸头孢噻呋注射液在白羽鸡体内的药物动力学参数变化规律。在给白羽鸡肌肉注射药物后,在0至48小时内于不同时间点采集血样,用碘乙酰胺衍生,把二硫赤鲜醇作为提取液,以水-三氟乙酸-乙腈(700∶1∶300)作为流动相,266 nm紫外检测。标准曲线线性相关很好,相关系数都在0.995以上。最低检测限为0.05μg/mL;最低定量限为0.1μg/mL,回收率都在90%以上。日间变异系数小于0.1,日内变异系数小于0.05。结果表明,新研制盐酸头孢噻呋的药物动力学参数符合产品要求。三种剂型达峰时间相同;美国盐酸头孢噻呋和新研制盐酸头孢噻呋的半衰期相似,大中农盐酸头孢噻呋半衰期相对要短,但总体三种剂型的半衰期差异不显著;新研制的盐酸头孢噻呋最高血药浓度比美国盐酸头孢噻呋和大中农盐酸头孢噻呋相对高些,美国盐酸头孢噻呋和大中农盐酸头孢噻呋最高血药浓度相当,但总体三种剂型的血药浓度半衰期差异不显著。  相似文献   

6.
为评价盐酸头孢噻呋乳膏剂治疗临床型奶牛乳房炎的治疗效果,试验选择80头临床型乳房炎奶牛,随机分为4组,分别乳管注入低、中、高剂量的盐酸头孢噻呋乳膏剂和盐酸头孢噻呋注入剂,进行临床疗效观察。结果显示,低、中、高剂量的试验组、阳性对照组药物对临床型奶牛乳房炎的治愈率分别为33.3%、71.4%、78.3%和76.7%,总有效率分别为57.8%、85.7%、87.0%和88.4%,治疗效果显著。建议盐酸头孢噻呋乳膏剂临床推荐剂量为,注入300 mg/乳管,1次/d,连用3d,对临床型奶牛乳房炎具有良好的治疗作用。  相似文献   

7.
为了研究3种β-内酰胺类抗生素对化脓隐秘杆菌分离株的体外抗菌活性及抗生素后效应,采用试管液体二倍稀释法测定抗菌药物对化脓隐秘杆菌的体外抗菌活性,采用平板菌落计数法绘制3种β-内酰胺类抗生素对化脓隐秘杆菌分离株的时间-杀菌曲线。结果青霉素、头孢氨苄和头孢噻呋对化脓隐秘杆菌分离株的最低抑菌浓度(MIC)分别为0.5、2μg/m L和1μg/m,最低杀菌浓度(MBC)分别为4、16μg/m L和16μg/m L;头孢噻呋对化脓隐秘杆菌的杀菌速率最快,青霉素次之;头孢噻呋对化脓隐秘杆菌分离株的抗生素后效应(PAE)较强(3.76 h),青霉素对化脓隐秘杆菌分离株的PAE较弱(2.31 h)。  相似文献   

8.
建立超高效液相色谱-光电二极管阵列法(UPLC-PDA)测定头孢噻呋晶体注射液中主成分头孢噻呋的含量。采用反相超高效液相色谱法对头孢噻呋进行色谱分离和快速定量测定。以ACQUITY UPLC~(TM)C8色谱柱(2.1 mm×100 mm,1.7μm)为分离柱,柱温:35℃;以乙腈-水(0.1%甲酸)进行梯度洗脱;流速:0.35 mL/min;进样量:1μL;检测波长为292 nm。通过光谱图、保留时间和峰面积参数对头孢噻呋进行定性、定量检测。头孢噻呋在4～200μg/mL的范围内线性关系良好(R~20.9998);方法检测限为2μg/mL、定量限为4μg/mL,完全满足检测需求。该方法色谱分离较好,分析速度较快,前处理简单,适用于头孢噻呋晶体注射液中主成分头孢噻呋含量的检测。  相似文献   

9.
黑龙江省某奶牛场奶牛乳房炎发病率高,牛乳中体细胞超标严重,严重影响该奶牛场的经济效益。为了明确引起该奶牛场奶牛乳房炎的主要致病病原菌,筛选敏感药物给出治疗方案。本实验对该奶牛场中30份奶牛乳房炎乳汁进行乳样处理、细菌培养、药敏试验及DNA提取和PCR扩增。通过DNA提取和PCR扩增确定其主要致病病原菌大多为无乳链球菌、停乳链球菌、肠球菌及少量金黄色葡萄球菌。乳样中并未检测出支原体、乳房链球菌及变形杆菌。药敏试验结果表明,该场患病奶牛对阿莫西林、头孢噻呋钠敏感,对一种商品名为惠可宁的硫酸头孢喹肟乳房注入剂耐药性明显。最终得出该厂患乳房炎奶牛的乳汁中分离出的细菌大多数为停乳链球菌,无乳链球菌,肠球菌和少量的金黄色葡萄球菌。当本地区奶牛检测为乳房炎时,可首选阿莫西林,头孢噻呋钠等敏感药物治疗,对奶牛乳房炎的治疗具有积极的指导意义。  相似文献   

10.
为了探讨头孢洛宁乳房注入剂对干乳期乳腺炎的防治作用,本研究采用微量稀释法测定比较了头孢洛宁、头孢匹林、阿莫西林和氯唑西林对乳腺炎病原菌(大肠杆菌、金黄色葡萄球菌、乳房链球菌、停乳链球菌、无乳链球菌)的体外抗菌活性;并且,随机选择60头进入干乳期的临床健康奶牛,在最后一次挤奶后每头牛的每个乳区分别灌注一管受试药物或对照药物(氨苄西林-苄星氯唑西林乳房注入剂)。对入选的每头奶牛分别在干奶前、以及产后1、3、5 d,采集每个乳区的乳样进行体细胞计数和细菌学检查。在药物处理后至产后14 d内,每天对受试动物进行临床型乳腺炎检查。结果显示,头孢洛宁、头孢匹林、阿莫西林、氯唑西林对分离自奶牛乳腺炎的大肠杆菌MIC_(50)分别为4、8、8μg/mL128μg/mL;对金黄色葡萄球菌的MIC_(50)分别为0.125、0.25、2、1μg/mL;对乳房链球菌的MIC_(50)分别为4、8、16、128μg/mL;对停乳链球菌的MIC_(50)分别为8、8、8、128μg/mL;对无乳链球菌MIC_(50)分别为0.25、4、0.25、32μg/mL。临床药学研究显示,头孢洛宁乳房注入剂对干乳期奶牛乳腺炎具有良好的防治效果,对不同细菌感染治愈率介于66.6%～100%之间,新感染发生率低于8.3%。在治愈率、新感染率及细菌学清除率方面和对照药物(氨苄西林-苄星氯唑西林乳房注入剂)相比均无显著性差异。表明头孢洛宁对引起奶牛乳腺炎的主要病原菌均具有良好的抗菌活性,干乳期奶牛每乳区灌注一管250 mg的头孢洛宁干乳期乳房注入剂能有效治疗干乳期隐性乳腺炎和预防新的乳腺炎感染。  相似文献   

11.
OBJECTIVE: To determine the elimination kinetics of ceftiofur hydrochloride in milk after intramammary administration in lactating dairy cows. DESIGN: Prospective study. ANIMALS: 5 lactating dairy cows. PROCEDURE: After collection of baseline milk samples, 300 mg (6 mL) of ceftiofur was infused into the left front and right rear mammary gland quarters of each cow. Approximately 12 hours later, an additional 300 mg of ceftiofur was administered into the same mammary gland quarters after milking. Milk samples were collected from each mammary gland quarter every 12 hours for 10 days. Concentrations of ceftiofur and its metabolites in each milk sample were determined to assess the rate of ceftiofur elimination. RESULTS: Although there were considerable variations among mammary gland quarters and individual cows, ceftiofur concentrations in milk from all treated mammary gland quarters were less than the tolerance (0.1 microg/mL) set by the FDA by 168 hours (7 days) after the last intramammary administration of ceftiofur. No drug concentrations were detected in milk samples beyond this period. Ceftiofur was not detected in any milk samples from nontreated mammary gland quarters throughout the study. CONCLUSIONS AND CLINICAL RELEVANCE: Ceftiofur administered by the intramammary route as an extra-label treatment for mastitis in dairy cows reaches concentrations in milk greater than the tolerance set by the FDA. Results indicated that milk from treated mammary gland quarters should be discarded for a minimum of 7 days after intramammary administration of ceftiofur. Elimination of ceftiofur may be correlated with milk production, and cows producing smaller volumes of milk may have prolonged withdrawal times.  相似文献   

12.
Five dairy goats were used to determine the milk and serum concentrations along with elimination characteristics of ceftiofur following intramammary administration. One udder half of each goat was infused twice with 125 mg ceftiofur with a 24‐h interval between infusions. Milk samples were collected at 1, 2, 8, and 12 h after the last infusion and then every 12 h for a total of 7 days. Blood was collected from each animal at 3, 8, 12, and 24 h after infusion and then every 24 h for 6 days. Following a washout period of 1 week, the experiment was repeated using the opposite udder half. The elimination half‐life of ceftiofur from the mammary gland was 4.7 h. The concentration of ceftiofur was greater than published MIC90 values for Staphylococcus spp. bacteria for 24 h. Ceftiofur was absorbed into systemic circulation from the mammary gland. The maximum concentration was 552 ng/mL at 3 h after infusion, and the serum elimination half‐life was 10 h. Intramammary infusion of 125 mg ceftiofur every 24 h can be expected to maintain drug concentration in milk above published MIC90 for Staphylococcus spp.  相似文献   

13.
OBJECTIVES: To determine the serum and synovial fluid concentrations of ceftiofur sodium after intraarticular (IA) and intravenous (IV) administration and to evaluate the morphologic changes after intraarticular ceftiofur sodium administration. STUDY DESIGN: Strip plot design for the ceftiofur sodium serum and synovial fluid concentrations and a split plot design for the cytologic and histopathologic evaluation. ANIMALS: Six healthy adult horses without lameness. METHODS: Stage 1: Ceftiofur sodium (2.2 mg/kg) was administered IV. Stage 2: 150 mg (3 mL) of ceftiofur sodium (pHavg 6.57) was administered IA into 1 antebrachiocarpal joint. The ceftiofur sodium was reconstituted with sterile sodium chloride solution (pH 6.35). The contralateral joint was injected with 3 mL of 0.9% sterile sodium chloride solution (pH 6.35). Serum and synovial fluid samples were obtained from each horse during each stage. For a given stage, each type of sample (serum or synovial fluid) was collected once before injection and 12 times after injection over a 24-hour period. All horses were killed at 24 hours, and microscopic evaluation of the cartilage and synovium was performed. Serum and synovial fluid concentrations of ceftiofur sodium were measured by using a microbiologic assay, and pharmacokinetic variables were calculated. Synovial fluid was collected from the active joints treated during stage 2 at preinjection and postinjection hours (PIH) 0 (taken immediately after injection of either the ceftiofur sodium or sodium chloride), 12, and 24, and evaluated for differential cellular counts, pH, total protein concentration, and mucin precipitate quality. RESULTS: Concentrations of ceftiofur in synovial fluid after IA administration were significantly higher (P = .0001) than synovial fluid concentrations obtained after IV administration. Mean peak synovial fluid concentrations of ceftiofur after IA and IV administration were 5825.08 microg/mL at PIH .25 and 7.31 microg/mL at PIH 4, respectively. Mean synovial fluid ceftiofur concentrations at PIH 24 after IA and IV administration were 4.94 microg/mL and .12 microg/mL, respectively. Cytologic characteristics of synovial fluid after IA administration did not differ from cytologic characteristics after IA saline solution administration. White blood cell counts after IA ceftiofur administration were < or =3,400 cells/ML. The mean synovial pH of ceftiofur treated and control joints was 7.32 (range, 7.08-7.5) and 7.37 (range, 7.31-7.42), respectively. Grossly, there were minimal changes in synovium or cartilage, and no microscopic differences were detected (P = .5147) between ceftiofur-treated joints and saline-treated joints. The synovial half-life of ceftiofur sodium after IA administration joint was 5.1 hours. CONCLUSIONS: Synovial concentrations after intraarticular administration of 150 mg of ceftiofur sodium remained elevated above minimal inhibitory concentration (MIC90) over 24 hours. After 2.2 mg/kg IV, the synovial fluid ceftiofur concentration remained above MIC no longer than 8 hours. CLINICAL RELEVANCE: Ceftiofur sodium may be an acceptable broad spectrum antimicrobial to administer IA in septic arthritic equine joints.  相似文献   

14.
OBJECTIVE: To determine the pharmacokinetics of ceftiofur sodium after IM and SC administration in green iguanas. ANIMALS: 6 male and 4 female adult green iguanas. PROCEDURE: In a crossover design, 5 iguanas received a single dose of ceftiofur sodium (5 mg/kg) IM, and 5 iguanas received the same dose SC. Blood samples were taken at 0, 20, and 40 minutes and 1, 2, 4, 8, 24, 48, and 72 hours after administration. After a 10-week washout period, each iguana was given the same dose via the reciprocal administration route, and blood was collected in the same fashion. Ceftiofur free-acid equivalents were measured via high-performance liquid chromatography. RESULTS: The first phase intercepts were significantly different between the 2 administration routes. Mean maximum plasma concentration was significantly higher with the IM (28.6 +/- 8.0 microg/mL) than the SC (18.6 +/- 8.3 microg/mL) administration route. There were no significant differences between terminal half-lives (harmonic mean via IM route, 15.7 +/- 4.7 hours; harmonic mean via SC route, 19.7 +/- 6.7 hours) and mean areas under the curve measured to the last time point (IM route, 11,722 +/- 7,907 microg x h/mL; SC route, 12,143 +/- 9,633 microg x h/mL). Ceftiofur free-acid equivalent concentrations were maintained > or = 2 microg/mL for > 24 hours via both routes. CONCLUSIONS AND CLINICAL RELEVANCE: A suggested dosing schedule for ceftiofur sodium in green iguanas for microbes susceptible at > 2 microg/mL would be 5 mg/kg, IM or SC, every 24 hours.  相似文献   

15.
Ceftiofur, a third generation cephalosporin, demonstrates in vitro efficacy against microorganisms isolated from septicemic neonatal foals. This pharmacokinetic study evaluated the intravenous and subcutaneous administration of ceftiofur sodium (5 mg/kg body weight; n = 6 per group) and subcutaneous administration of ceftiofur crystalline free acid (6.6 mg/kg body weight; n = 6) in healthy foals. Plasma ceftiofur- and desfuroylceftiofur-related metabolite concentrations were measured using high performance liquid chromatography following drug administration. Mean (±SD) noncompartmental pharmacokinetic parameters for i.v. and s.c. ceftiofur sodium were: AUC(0→∝) (86.4 ± 8.5 and 91 ± 22 h·μg/mL for i.v. and s.c., respectively), terminal elimination half-life (5.82 ± 1.00 and 5.55 ± 0.81 h for i.v. and s.c., respectively), C(max(obs)) (13 ± 1.9 μg/mL s.c.), T(max(obs)) (0.75 ± 0.4 h for s.c.). Mean (± SD) noncompartmental pharmacokinetic parameters for s.c. ceftiofur crystalline free acid were: AUC(0→∝) (139.53 ± 22.63 h·μg/mL), terminal elimination half-life (39.7 ± 14.7), C(max(obs)) (2.52 ± 0.35 μg/mL) and t(max(obs)) (11.33 ± 1.63 h). No adverse effects attributed to drug administration were observed in any foal. Ceftiofur- and desfuroylceftiofur-related metabolites reached sufficient plasma concentrations to effectively treat common bacterial pathogens isolated from septicemic foals.  相似文献   

16.
Time-related concentrations in milk of a combination of trimethoprim-sulphadiazine (TMP-SDZ) intramammary formulated infusion and its relationship with pathogenic bacteria strains minimum inhibitory concentrations (MICs) isolated from clinical mastitis cows were analysed. The MICs study was performed for Escherichia coli, Staphylococcus aureus and Streptococcus sp. strains. The SDZ concentrations in milk were analysed using high-performance liquid chromatography (HPLC) and TMP using a microbiological assay. Ten lactating cows milked three times daily were used in the time-concentration studies of TMP-SDZ. Milk samples (approximately 20 mL) from the treated mammary quarters were taken at 6, 12, 24, 30 and 36 h after first administration. In order to define the withdrawal time, milk samples from the treated mammary quarters were taken at 24, 36, 48, 72, 84 and 96 h, after finishing the therapy. The MICs fluctuated between 1 and 8 microg/mL. Effective therapeutic concentrations lasted for 36 h when intramammary infusion was repeated three times every 12 h. No TMP was detected in milk for 24 h after finishing therapy. Milk SDZ concentrations were below 0.1 microg/mL in all treated cows after 84 h finishing therapy. At 96 h after finishing therapy, no SDZ milk concentrations were found in six animals, although four animals of the experimental group still had concentrations of 0.07 microg/mL.  相似文献   

17.
Ceftiofur sodium, a broad-spectrum cephalosporin, is active against gram-positive and gram-negative pathogens of veterinary importance. Two studies were designed to compare the intramuscular bioavailability of the current sodium salt and the new hydrochloride salt in pigs at doses of either 3 mg or 5 mg ceftiofur equivalents (CE)/kg body weight. Twenty-six healthy young pigs were selected for these two-period, two-treatment crossover studies, 12 for the 3 mg/kg study and 14 for the 5 mg/kg study. Each animal received one intramuscular (i.m.) injection of ceftiofur sodium and one i.m. injection of ceftiofur hydrochloride with a 14-day washout period between the two treatments. Blood samples were collected serially for up to 96 h postinjection. Plasma samples were then analysed using a validated assay that measures ceftiofur and all desfuroylceftiofur-related metabolites by high-performance liquid chromatography. In the 3 mg/kg dosage study, average maximum plasma concentration (C(max)) after administration of ceftiofur sodium was 15.8+/-3.40 microg/mL at 0.4-4 h after injection. After administration of ceftiofur hydrochloride, the C(max) was 11.8+/-1.67 microg/mL at 1-4 h after injection. Concentrations of ceftiofur and metabolites 72 h after the injection were 0.392+/-0.162 microg/mL for ceftiofur hydrochloride and 0.270+/-0.118 microg/mL for ceftiofur sodium. The mean area under the curve (AUC), from time 0 to the limit of quantitation (AUC(O-LOQ)) after ceftiofur hydrochloride administration, was 216+/-28.0 microg x h/mL, compared to 169+/-45.4 microg x h/mL after ceftiofur sodium administration. The calculated time during which plasma concentrations remained above 0.02 microg/mL (t(>0.2)) was 85.3+/-10.6 h for ceftiofur sodium and 77.2+/-10.7 h for ceftiofur hydrochloride. In the 5 mg/kg dosage study, C(max) after administration of ceftiofur sodium was 28.3+/-4.45 microg/mL at 0.33-2 h after injection. After administration of ceftiofur hydrochloride, the C(max) was 29.7+/-6.72 microg/mL at 0.66-2 h after injection. Concentrations of ceftiofur and metabolites 96 h after the injection were 0.274+/-0.0550 microg/mL for ceftiofur hydrochloride and 0.224+/-0.0350 microg/mL for ceftiofur sodium. The mean AUC(O-LOQ) after ceftiofur hydrochloride administration was 382+/-89.8 microg x h/mL compared to 302+/-54.4 microg x h/mL after ceftiofur sodium administration. The t(>0.2) was 78.9+/-9.65 h for ceftiofur sodium and 94.2+/-8.64 h for ceftiofur hydrochloride. Based on the similarity of the pharmacokinetic parameters of the sodium and hydrochloride formulations of ceftiofur, similar therapeutic efficacy can be inferred for the two products.  相似文献   

18.
Pharmacokinetics of florfenicol 30% injectable solution was determined in lactating cows after intravenous, intramammary and intramuscular administration. Serum concentration-time data generated in the present study were analysed by non-compartmental methods based on statistical moment theory. Florfenicol half-life was 176 min, mean residence time 129 min, volume of distribution at steady-state 0.35 L/kg, and total body clearance 2.7 mL/min·kg after intravenous administration at 20 mg/kg. The absorption after intramuscular administration appeared slow and the kinetic parameters and the serum concentration vs. time curve were characteristic of absorption rate-dependent elimination. The absorption after intramammary administration of florfenicol at 20 mg/kg was good (53.9%) and resulted in serum concentrations with apparent clinical significance. The intramammary administration resulted in serum florfenicol concentrations that were significantly higher than the respective serum concentrations following Intravenous administration 4 h after administration and thereafter. Florfenicol absorption was faster from the mammary gland than from the muscle. The maximum serum concentrations ( C max) were 6.9 μg/mL at 360 min after intramammary administration and 2.3 μg/mL at 180 min after intramuscular administration. The bioavailability of florfenicol was 54% and 38% after intramammary and intramuscular administration, respectively. The C max in milk was 5.4 μg/mL at 180 min after intravenous and 1.6 μg/mL at 600 min after intramuscular administration.  相似文献   

19.
OBJECTIVE: To evaluate the elimination kinetics of chlorhexidine in milk when used as an intramammary infusion to stop lactation in cows. DESIGN: Prospective study. ANIMALS: 6 cows. PROCEDURE: The study was performed in 2 phases. Three cows were studied in each phase. All cows were treated with chlorhexidine suspension by infusion into a mastitic mammary gland quarter after 2 milkings 24 hours apart. Foremilk samples (100 mL) were collected from treated and untreated (controls) mammary gland quarters of each cow. Chlorhexidine was extracted from raw milk, and residue concentrations were quantified by use of high-performance liquid chromatography. Foremilk samples from days 2, 5, and 8 were analyzed in phase I, and samples from time 0 and days 3, 7, 14, 21, 28, 35, and 42 were analyzed in phase II. RESULTS: In phases I and II, there was no quantifiable transference of chlorhexidine to milk in untreated mammary gland quarters. Measurable chlorhexidine residues were found in milk from treated mammary gland quarters of 2 cows throughout the 42-day sample period in phase II. Estimated mean elimination half-life for chlorhexidine in milk was 11.5 days. CONCLUSIONS AND CLINICAL RELEVANCE: On the basis of the long elimination half-life of chlorhexidine in milk from treated mammary gland quarters, the lack of human dietary exposure data to suggest a food tolerance for chlorhexidine in food products, and the Food and Drug Administration's published zero tolerance for chlorhexidine in uncooked edible calf tissues, we do not recommend extralabel use of chlorhexidine suspension as a treatment to stop lactation in mastitic mammary gland quarters of cows.  相似文献   

20.
The objectives of this study were to determine pharmacokinetics of intravenous (i.v.) ceftiofur in foals, to compare ultra-high performance liquid chromatography tandem mass spectometry (UPLC-MS/MS) and microbiologic assay for the measurement of ceftiofur concentrations, and to determine the minimum inhibitory concentration ( MIC ) of ceftiofur against common equine bacterial pathogens. In a cross-over design, ceftiofur sodium was administered i.v. to six foals (1–2 days-of-age and 4–5 weeks-of-age) at dosages of 5 and 10 mg/kg. Subsequently, five doses of ceftiofur were administered i.v. to six additional foals between 1 and 5 days of age at a dose of 5 mg/kg q 12 h. Concentrations of desfuroylceftiofur acetamide (DCA), the acetamide derivative of ceftiofur and desfuroylceftiofur-related metabolites were measured in plasma, synovial fluid, urine, and CSF by use of UPLC-MS/MS. A microbiologic assay was used to measure ceftiofur activity for a subset of plasma samples. Following i.v. administration of ceftiofur at a dose of 5 mg/kg to 1–2 day-old foals, DCA had a t ½ of 7.8 ± 0.1 h, a body clearance of 74.4 ± 8.4 mL/h/kg, and an apparent volume of distribution of 0.83 ± 0.09 L/kg. After multiple i.v. doses at 5 mg/kg, DCA concentrations in CSF were significantly lower than concurrent plasma concentrations. Ceftiofur activity using a microbiologic assay significantly underestimated plasma concentrations of DCA. The MIC of ceftiofur required to inhibit growth of 90% of isolates of Escherichia coli , Pasteurella spp, Klebsiella spp, and β-hemolytic streptococci was <0.5 μg/mL. Intravenous administration of ceftiofur sodium at the rate of 5 mg/kg every 12 h would provide sufficient coverage for the treatment of susceptible bacterial isolates.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号