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 15 毫秒
1.
The pharmacokinetics and bioavailability of rifampin were determined after IV (10 mg/kg of body weight) and intragastric (20 mg/kg of body weight) administration to 6 healthy, adult horses. After IV administration, the disposition kinetics of rifampin were best described by a 2-compartment open model. A rapid distribution phase was followed by a slower elimination phase, with a half-life (t1/2[beta]) of 7.27 +/- 1.11 hours. The mean body clearance was 1.49 +/- 0.41 ml/min.kg, and the mean volume of distribution was 932 +/- 292 ml/kg, indicating that rifampin was widely distributed in the body. After intragastric administration of rifampin in aqueous suspension, a brief lag period (0.31 +/- 0.09 hour) was followed by rapid, but incomplete, absorption (t1/2[a] = 0.51 +/- 0.32 hour) and slow elimination (t1/2[d] = 11.50 +/- 1.55 hours). The mean bioavailability (fractional absorption) of the administered dose during the first 24 hours was 53.94 +/- 18.90%, and we estimated that 70.0 +/- 23.6% of the drug would eventually be absorbed. The mean peak plasma rifampin concentration was 13.25 +/- 2.70 micrograms/ml at 2.5 +/- 1.6 hours after dosing. All 6 horses had plasma rifampin concentrations greater than 2 micrograms/ml by 45 minutes after dosing; concentrations greater than 3 micrograms/ml persisted for at least 24 hours. Mean plasma rifampin concentrations at 12 and 24 hours after dosing were 6.86 +/- 1.69 micrograms/ml and 3.83 +/- 0.87 micrograms/ml, respectively. We tested 162 isolates of 16 bacterial species cultured from clinically ill horses for susceptibility to rifampin.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

2.
The pharmacokinetics and bioavailability of probenecid given IV and orally at the dosage level of 10 mg/kg of body weight to mares were investigated. Probenecid given IV was characterized by a rapid disposition phase with a mean half-life of 14.0 minutes and a subsequent slower elimination phase with a mean half-life of 87.8 minutes in 5 of 6 mares. In the remaining mare, a rapid disposition phase was not observed, and the half-life of the elimination phase was slower (172 minutes). The mean residence time of probenecid averaged 116 minutes for all 6 mares and 89.2 minutes for the 5 mares with biphasic disposition. The total plasma clearance of probenecid averaged 1.18 +/- 0.49 ml/min/kg, whereas renal clearance accounted for 42.6 +/- 9.3% of the total clearance. The steady-state volume of distribution of probenecid averaged 116 +/- 28.2 ml/kg. Plasma protein binding of probenecid was extensive, with 99.9% of the drug bound at plasma probenecid concentrations of 10 micrograms/ml. The maximum plasma probenecid concentration after 10 mg/kg orally averaged nearly 30 micrograms/ml. The half-life of probenecid after oral administration was approximately 120 minutes. Oral bioavailability was good with greater than 90% of the dose absorbed. The effect of probenecid on tubular secretion of organic anions was evaluated by determining the pharmacokinetics of IV cefazolin (11 mg/kg) administered alone and 15 minutes after probenecid (10 mg/kg orally). Treatment with probenecid did not affect pharmacokinetic values of cefazolin. This failure of probenecid to alter the pharmacokinetics of cefazolin may be caused by insufficient plasma probenecid concentrations after the oral dose.  相似文献   

3.
Pharmacokinetics and bioavailability of cefazolin in horses   总被引：1，自引：0，他引：1  
The pharmacokinetics and bioavailability of cefazolin given (IV, IM) to horses at the dosage of 11 mg/kg were investigated. The disposition of cefazolin given by IV route was characterized by a rapid disposition phase with a half-life of 5 to 10 minutes and a subsequent slower elimination phase with a half-life of 35 to 46 minutes. The total plasma clearance of cefazolin averaged 5.51 ml/min/kg and was due mainly to renal clearance (5.39 ml/min/kg) of unchanged drug. The volume of distribution at steady-state averaged 188 ml/kg. Plasma protein binding of cefazolin at a concentration of 10 micrograms/ml averaged 8.1 +/- 1.9%. Given by the IM route, cefazolin was rapidly absorbed; the extent of bioavailability was 78.4 +/- 18.8%, and the terminal half-life ranged from 49 to 99 minutes. Thus, cefazolin was extensively absorbed, but was eliminated more slowly than after IV administration.  相似文献   

4.
Pharmacokinetics and bioavailability of cephalothin in horse mares   总被引：1，自引：0，他引：1  
The pharmacokinetics and bioavailability of cephalothin given to 6 horse mares at a dosage level of 11 mg/kg of body weight IV or IM were investigated. The disposition of cephalothin given IV was characterized by a rapid disposition phase with a mean half-life of 2.89 minutes and a subsequent slower elimination phase with a mean half-life of only 14.7 minutes. The mean residence time of cephalothin was 10.6 +/- 2.11 minutes. The total plasma clearance of cephalothin averaged 13.6 ml/min/kg and was caused by metabolism and renal elimination. Renal clearance of cephalothin averaged 1.32 ml/min/kg and accounted for elimination of about 10.1% of the administered dose. The volume of distribution at steady state averaged 151 mg/kg. Plasma protein binding of cephalothin at a concentration of 10 micrograms/ml averaged 17.9 +/- 2.5%. Cephalothin was rapidly metabolized to desacetylcephalothin. Maximum plasma desacetylcephalothin concentrations were observed in the blood samples collected 5 minutes after IV doses and averaged 22.9 micrograms/ml. The apparent half-life of desacetylcephalothin in plasma was 41.6 minutes and its renal clearance averaged 4.49 +/- 2.43 ml/min/kg. An average of 33.9% of the dose was recovered in the urine as desacetylcephalothin. The maximum plasma cephalothin concentration after IM administration was 11.3 +/- 3.71 micrograms/ml. The terminal half-life was 47.0 minutes and was longer than the half-life after IV administration. The bioavailability of cephalothin given IM ranged from 38.3% to 93.1% and averaged 65.0 +/- 20.5%.  相似文献   

5.
The pharmacokinetics and bioavailability of enrofloxacin were determined after IV and IM administration of 5 mg/kg of body weight to 6 healthy adult rabbits. Using nonlinear least-squares regression methods, data obtained were best described by a 2-compartment open model. After IV administration, a rapid distribution phase was followed by a slower elimination phase, with a half-life of 131.5 +/- 17.6 minutes. The mean body clearance rate was 22.8 +/- 6.8 ml/min/kg, and the mean volume of distribution was 3.4 +/- 0.9 L/kg. This large volume of distribution and the K12/K21 ratio close to 1, indicated that enrofloxacin was widely distributed in the body, but not retained in tissues. After a brief lag period (6.2 +/- 2.86 min), IM absorption was rapid (4.1 +/- 1.3 min) and almost complete. The mean extent of IM absorption was 92 +/- 11%, and maximal plasma concentration of 3.04 +/- 0.34 micrograms/ml was detected approximately 10 minutes after administration.  相似文献   

6.
The pharmacokinetics and bioavailability of theophylline in horses were investigated following both intravenous and intragastric administration of aminophylline solutions at doses corresponding to 15 and 10 mg/kg theophylline base. A rapid distributive phase with a half-life of approximately 15-30 min was followed by a slower elimination half-life averaging 15-17 h. The apparent volume of distribution averaged 850-900 ml/kg. Theophylline, administered as aminophylline solution, was both rapidly and completely absorbed from the equine digestive tract. Based on the bioavailability and disposition kinetics of theophylline, an intragastric dosage regimen for aminophylline consisting of the administration of 5 mg/kg at 12 h intervals would be expected to maintain plasma theophylline concentrations within the therapeutic range.  相似文献   

7.
Six mature Holstein bulls were each given 10 mg of phenylbutazone (PBZ)/kg of body weight, PO. Of the 6 bulls, 3 were given 10 mg of PBZ/kg by rapid IV administration 4 weeks later. Plasma concentration-vs-time data were analyzed, using nonlinear regression modeling (sum of exponential functions). The harmonic mean of the biologic half-life of PBZ was 62.6 +/- 12.9 hours after oral administration and 61.6 +/- 7.2 hours after IV administration. The mean residence time was 94.61 +/- 8.44 hours and 90.49 +/- 8.93 hours for oral and IV administration, respectively. The mean total body clearance was 0.0015 +/- 0.0003 L/h/kg, with the mean apparent volume of distribution 0.134 +/- 0.021 L/kg. Mean bioavailability was 73 +/- 2% after oral administration. Phenylbutazone was adequately absorbed from the gastrointestinal tract in bulls. The apparent volume of distribution was small, indicating that PBZ distributed mainly into plasma and extracellular fluid. The total body clearance was also small, which accounted for the long half-life of PBZ in bulls.  相似文献   

8.
Norfloxacin was given to 2 groups of chickens (8 chickens/group) at a dosage of 8 mg/kg of body weight, IV and orally. For 24 hours, plasma concentration was monitored serially after each administration. Another group of chickens (n = 30) was given 8 mg of norfloxacin/kg orally every 24 hours for 4 days, and plasma and tissue concentrations of norfloxacin and its major metabolites desethylenenorfloxacin and oxonorfloxacin were determined serially after the last administration of the drug. Plasma and tissue concentrations of norfloxacin, desethylenenorfloxacin, and oxonorfloxacin were measured by use of high-performance liquid chromatography. Pharmacokinetic variables were calculated, using a 2-compartment open model. For norfloxacin, the elimination half-life (t1/2 beta) and the mean +/- SEM residence time for plasma were 12.8 +/- 0.59 and 15.05 +/- 0.81 hours, respectively, after oral administration and 8.0 +/- 0.3 and 8.71 +/- 0.23 hours, respectively, after IV administration. After single oral administration, norfloxacin was absorbed rapidly, with Tmax of 0.22 +/- 0.02 hour. Maximal plasma concentration was 2.89 +/- 0.20 microgram/ml. Oral bioavailability of norfloxacin was found to be 57.0 +/- 2.4%. In chickens, norfloxacin was mainly converted to desethylenenorfloxacin and oxonorfloxacin. Norfloxacin parent drug and its 2 major metabolites were widely distributed in tissues. Considerable tissue concentrations of norfloxacin, desethylenenorfloxacin, and oxonorfloxacin were found when norfloxacin was administered orally (8 mg/kg on 4 successive days). The concentration of the parent fluoroquinolone in fat, kidneys, and liver was 0.05 micrograms/g on day 12 after the end of dosing.  相似文献   

9.
Pharmacokinetics of cefotaxime in the domestic cat   总被引：1，自引：0，他引：1  
Cefotaxime was administered as single IV or IM dose for the purpose of examining its pharmacokinetics in healthy cats. The mean predicted plasma concentration of cefotaxime in 6 cats at 0 time after a single IV dosage of 10 mg/kg of body weight was 88.9 micrograms/ml. The mean plasma concentrations decreased to 10.8 micrograms/ml at 2 hours, 3.7 micrograms/ml at 3 hours, and 0.5 microgram/ml at 6 hours. The half-life was 0.98 +/- 0.25 hour (mean +/- SD), and the total body clearance was determined to be 2.76 +/- 1.25 ml/min/kg. After a single IM injection of 10 mg/kg of body weight, the mean maximum observed plasma concentration was 36.2 micrograms/ml at 0.75 hour. The mean absorption half-life was 0.24 hour. In 2 animals, the bioavailability of an IM injection was 98.2% and 93.0%.  相似文献   

10.
Pharmacokinetics of amikacin in cats   总被引：1，自引：0，他引：1  
Six mixed-breed adult cats were given 5 mg of amikacin sulfate/kg of body weight by rapid IV, IM, and SC routes of administration. The serum concentration-vs-time data were analyzed, using a noncompartmental model. The harmonic mean +/- pseudo-SD of the effective half-life of amikacin was 78.8 +/- 19.3 minutes after IV administration, 118.7 +/- 14.4 minutes after IM administration, and 117.7 +/- 12.8 minutes after SC administration. The arithmetic mean +/- SD of mean residence time was 118.3 +/- 21.7 minutes, 173.4 +/- 19.9 minutes, and 171.7 +/- 19.1 minutes after IV, IM, and SC drug administration, respectively. The mean apparent volume of distribution at steady state was 0.17 +/- 0.02 L/kg, and the mean total body clearance was 1.46 +/- 0.26 ml/min/kg. Mean bioavailability was 95 +/- 20% after IM administration and 123 +/- 33% after SC drug administration. A recommended dosage of 10 mg/kg, q 8 h can be expected to provide a therapeutic serum concentration of amikacin with a mean steady-state concentration of 14 micrograms/ml. The SC route of administration is preferred, because of rapid absorption, good bioavailability, and ease of administration.  相似文献   

11.
OBJECTIVE: To characterize pharmacokinetics of voriconazole in horses after oral and IV administration and determine the in vitro physicochemical characteristics of the drug that may affect oral absorption and tissue distribution. ANIMALS: 6 adult horses. PROCEDURES: Horses were administered voriconazole (1 mg/kg, IV, or 4 mg/kg, PO), and plasma concentrations were measured by use of high-performance liquid chromatography. In vitro plasma protein binding and the octanol:water partition coefficient were also assessed. RESULTS: Voriconazole was adequately absorbed after oral administration in horses, with a systemic bioavailability of 135.75 +/- 18.41%. The elimination half-life after a single orally administered dose was 13.11 +/- 2.85 hours, and the maximum plasma concentration was 2.43 +/- 0.4 microg/mL. Plasma protein binding was 31.68%, and the octanol:water partition coefficient was 64.69. No adverse reactions were detected during the study. CONCLUSIONS AND CLINICAL RELEVANCE: Voriconazole has excellent absorption after oral administration and a long half-life in horses. On the basis of the results of this study, it was concluded that administration of voriconazole at a dosage of 4 mg/kg, PO, every 24 hours will attain plasma concentrations adequate for treatment of horses with fungal infections for which the fungi have a minimum inhibitory concentration 相似文献   

12.
Pharmacokinetic properties of enrofloxacin in rabbits.   总被引：4，自引：0，他引：4  
The pharmacokinetic properties of the fluoroquinolone antimicrobial enrofloxacin were studied in New Zealand White rabbits. Four rabbits were each given enrofloxacin as a single 5 mg/kg of body weight dosage by IV, SC, and oral routes over 4 weeks. Serum antimicrobial concentrations were determined for 24 hours after dosing. Compartmental modeling of the IV administration indicated that a 2-compartment open model best described the disposition of enrofloxacin in rabbits. Serum enrofloxacin concentrations after SC and oral dosing were best described by a 1- and 2-compartment model, respectively. Overall elimination half-lives for IV, SC, and oral routes of administration were 2.5, 1.71, and 2.41 hours, respectively. The half-life of absorption for oral dosing was 26 times the half-life of absorption after SC dosing (7.73 hours vs 0.3 hour). The observed time to maximal serum concentration was 0.9 hour after SC dosing and 2.3 hours after oral administration. The observed serum concentrations at these times were 2.07 and 0.452 micrograms/ml, respectively. Mean residence times were 1.55 hours for IV injections, 1.46 hours for SC dosing, and 8.46 hours for oral administration. Enrofloxacin was widely distributed in the rabbit as suggested by the volume of distribution value of 2.12 L/kg calculated from the IV study. The volume of distribution at steady-state was estimated at 0.93 L/kg. Compared with IV administration, bioavailability was 77% after SC dosing and 61% for gastrointestinal absorption. Estimates of predicted average steady-state serum concentrations were 0.359, 0.254, and 0.226 micrograms/ml for IV, SC, and oral administration, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

13.
Absorption rate and plasma and fat disposition of lindane after various lindane percutaneous treatments in shorn and unshorn sheep were investigated. To analyze data with a deconvolution method, IV administration was performed to determine the basic pharmacokinetic values of lindane in sheep. After IV administration, the steady state volume of distribution was very high (8.07 +/- 3.60 L/kg of body weight), and the mean residence time was long (28.1 +/- 11.7 hours). Deconvolution analysis indicated that lindane absorption was continuous until 33 to 41 days after spraying with a 0.025% lindane solution. Total amount of absorbed lindane in shorn (15,171 +/- 4,463 micrograms/kg) sheep was about twice that in unshorn (7,615 +/- 3,128 micrograms/kg) sheep; from deconvolution analysis, it was calculated that the time required for 50% of the available dose to be absorbed was between 115 and 179 hours. After percutaneous lindane administration, the fat concentration was compared with the available lindane dose. The apparent half-life of lindane elimination in fat was 225 +/- 47.4 hours, which is similar to the value calculated for the absorption rate constant. By comparing fat and plasma concentrations, it was calculated that for a mean plasma concentration of 5 ng/ml, the fat lindane concentration was 1.65 +/- 0.87 micrograms/g (ie, lower than the generally accepted tolerance level of 2 micrograms/g).  相似文献   

14.
Caffeine (4 mg/kg) was given by rapid IV injection to 4 horses. Plasma concentrations of the drug peaked at 10 micrograms/ml and decreased rapidly at first, and then more slowly, with an apparent beta-phase half-life of 18.2 hours. Urinary concentrations of caffeine were remarkably consistent at about 3 times plasma values of the drug. Caffeine was detectable in both plasma and urine of the horses for up to 9 days after dosing. After oral administration, caffeine was absorbed poorly with an apparent bioavailability of 39%. Although blood concentrations of caffeine peaked rapidly after oral administration, its apparent plasma half-life by this route was about 42 hours. These observations identify the possible existence of a slowly absorbed pool of caffeine in the gastrointestinal tract after oral administration. When caffeine-treated horses were given fentanyl, the locomotor response to fentanyl was enhanced. This potentiation of the fentanyl response peaked at between 0 and 4 hours after dosing and was gone by 72 hours after caffeine dosing. The data indicate that the probability of behavioral stimulation due to caffeine by 72 hours after dosing may be small.  相似文献   

15.
Tramadol is a centrally acting analgesic drug that has been used clinically for the last two decades to treat moderate to moderately severe pain in humans. The present study investigated tramadol administration in horses by intravenous, intramuscular, oral as immediate-release and oral as sustained-release dosage-form routes. Seven horses were used in a four-way crossover study design in which racemic tramadol was administered at 2 mg/kg by each route of administration. Altogether, 23 blood samples were collected between 0 and 2880 min. The concentration of tramadol and its M1 metabolite were determined in the obtained plasma samples by use of an LC/MS/MS method and were used for pharmacokinetic calculations. Tramadol clearance, apparent volume of distribution at steady-state, mean residence time (MRT) and half-life after intravenous administration were 26+/-3 mL/min/kg, 2.17+/-0.52 L/kg, 83+/-10 min, and 82+/-10 min, respectively. The MRT and half-life after intramuscular administration were 155+/-23 and 92+/-14 min. The mean absorption time was 72+/-22 min and the bioavailability 111+/-39%. Tramadol was poorly absorbed after oral administration and only 3% of the administered dose was found in systemic circulation. The fate of the tramadol M1 metabolite was also investigated. M1 appeared to be a minor metabolite in horses, which could hardly be detected in plasma samples. The poor bioavailability after oral administration and the short half-life of tramadol may restrict its usefulness in clinical applications.  相似文献   

16.
OBJECTIVE: To determine the pharmacokinetics of enrofloxacin administered IV and orally to foals. ANIMALS: 5 clinically normal foals. PROCEDURE: A 2-dose cross-over trial with IV and oral administration was performed. Enrofloxacin was administered once IV (5 mg/kg of body weight) to 1-week-old foals, followed by 1 oral administration (10 mg/kg) after a 7-day washout period. Blood samples were collected for 48 hours after the single dose IV and oral administrations and analyzed for plasma enrofloxacin and ciprofloxacin concentrations by use of high-performance liquid chromatography. RESULTS: For IV administration, mean +/- SD total area under the curve (AUC0-infinity) was 48.54 +/- 10.46 microg x h/ml, clearance was 103.72 +/- 0.06 ml/kg/h, half-life (t1/2beta) was 17.10 +/- 0.09 hours, and apparent volume of distribution was 2.49 +/- 0.43 L/kg. For oral administration, AUC0-infinity was 58.47 +/- 16.37 microg x h/ml, t1/2beta was 18.39 +/- 0.06 hours, maximum concentration (Cmax) was 2.12 +/- 00.51 microg/ml, time to Cmax was 2.20 +/- 2.17 hours, mean absorption time was 2.09 +/- 0.51 hours, and bioavailability was 42 +/- 0.42%. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with adult horses given 5 mg of enrofloxacin/kg IV, foals have higher AUC0-infinity, longer t1/2beta, and lower clearance. Concentration of ciprofloxacin was negligible. Using a target Cmax to minimum inhibitory concentration ratio of 1:8 to 1:10, computer modeling suggests that 2.5 to 10 mg of enrofloxacin/kg administered every 24 hours would be effective in foals, depending on minimum inhibitory concentration of the pathogen.  相似文献   

17.
OBJECTIVE: To determine the pharmacokinetics of acetazolamide administered IV and orally to horses. ANIMALS: 6 clinically normal adult horses. PROCEDURE: Horses received 2 doses of acetazolamide (4 mg/kg of body weight, IV; 8 mg/kg, PO), and blood samples were collected at regular intervals before and after administration. Samples were assayed for acetazolamide concentration by high-performance liquid chromatography, and concentration-time data were analyzed. RESULTS: After IV administration of acetazolamide, data analysis revealed a median mean residence time of 1.71 +/- 0.90 hours and median total body clearance of 263 +/- 38 ml/kg/h. Median steady-state volume of distribution was 433 +/- 218 ml/kg. After oral administration, mean peak plasma concentration was 1.90 +/- 1.09 microg/ml. Mean time to peak plasma concentration was 1.61 +/- 1.24 hours. Median oral bioavailability was 25 +/- 6%. CONCLUSIONS AND CLINICAL RELEVANCE: Oral pharmacokinetic disposition of acetazolamide in horses was characterized by rapid absorption, low bioavailability, and slower elimination than observed initially after IV administration. Pharmacokinetic data generated by this study should facilitate estimation of appropriate dosages for acetazolamide use in horses with hyperkalemic periodic paralysis.  相似文献   

18.
The pharmacokinetics, bioavailability, and distribution to the tears of ormetoprim (OMP; 5.5 mg/kg of body weight) and sulfadimethoxine (SDM; 27.5 mg/kg of body weight) were determined following IV or oral administration to 6 Holstein steers. After IV administration, the disposition kinetics of both drugs were best described by a 2-compartment open model. Sulfadimethoxine had a moderately rapid distribution phase, followed by a slower elimination phase, with a mean half-life (t 1/2) of 7.91 hours. The mean volume of distribution of SDM was 185 ml/kg, and the mean body clearance was 0.28 ml/min X kg. The concentration of SDM in tears was lower than the corresponding plasma concentration, and the elimination of SDM from tears (t 1/2 = 3.02 hours) was significantly faster than its elimination from plasma (t 1/2 = 7.91 hours). The disposition of OMP administered IV was characterized by a rapid distribution phase, followed by a rapid elimination phase (t 1/2 = 1.37 hours). The high values of the mean volume of distribution (1,450 ml/kg) and mean rate of body clearance (13.71 ml/min X kg) indicated that OMP was widely distributed in the body and was rapidly cleared from the body. Ormetoprim concentrations in tears exceeded corresponding plasma concentrations, and the elimination of OMP from tears was significantly slower (t 1/2 = 1.91 hours) than from plasma (t 1/2 = 1.37 hours). After oral administration of an OMP-SDM combination in bolus form, the absorption of SDM was slow (absorption t 1/2 = 3.32 hours), but complete.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

19.
Single-dose disposition kinetics of difloxacin (5mg/kg bodyweight) were determined in clinically normal male dromedary camels (n=6) following intravenous (IV) and intramuscular (IM) administration. Difloxacin concentrations were determined by high performance liquid chromatography with fluorescence detection. The concentration-time data were analysed by compartmental and non-compartmental kinetic methods. Following a single IV injection, the plasma difloxacin concentration-time curve was best described by a two-compartment open model, with a distribution half-life (t(1/2alpha)) of 0.22+/-0.02h and an elimination half-life (t(1/2beta)) of 2.97+/-0.31h. Steady-state volume of distribution (V(dss)) and total body clearance (Cl(tot)) were 1.02+/-0.21L/kg and 0.24+/-0.07L/kg/h, respectively. Following IM administration, the absorption half-life (t(1)(/)(2ab)) and the mean absorption time (MAT) were 0.44+/-0.03h and 1.53+/-0.22h, respectively. The peak plasma concentration (C(max)) of 2.84+/-0.34microg/mL was achieved at 1.42+/-0.21h. The elimination half-life (t(1/2el)) and the mean residence time (MRT) was 3.46+/-0.42h and 5.61+/-0.23h, respectively. The in vitro plasma protein binding of difloxacin ranged from 28-43% and the absolute bioavailability following IM administration was 93.51+/-11.63%. Difloxacin could be useful for the treatment of bacterial infections in camels that are sensitive to this drug.  相似文献   

20.
OBJECTIVE: To study the pharmacokinetics of difloxacin (5 mg/kg) following IV, IM, and intragastric (IG) administration to healthy horses. ANIMALS: 6 healthy mature horses. PROCEDURES: A crossover study design with 3 phases was used (15-day washout periods between treatments). An injectable formulation of difloxacin (5%) was administered IV and IM in single doses (5 mg/kg); for IG administration, an oral solution was prepared and administered via nasogastric tube. Blood samples were collected before and at intervals after each administration. A high-performance liquid chromatography assay with fluorescence detection was used to determine plasma difloxacin concentrations. Pharmacokinetic parameters of difloxacin were analyzed. Plasma creatine kinase activity was monitored to assess tissue damage. RESULTS: Difloxacin plasma concentration versus time data after IV administration were best described by a 2-compartment open model. The disposition of difloxacin following IM or IG administration was best described by a 1-compartment model. Mean half-life for difloxacin administered IV, IM, and IG was 2.66, 5.72, and 10.75 hours, respectively. Clearance after IV administration was 0.28 L/kg.h. After IM administration, the absolute mean +/- SD bioavailability was 95.81 +/- 3.11% and maximum plasma concentration (Cmax) was 1.48 +/- 0.12 mg/L. After IG administration, the absolute bioavailability was 68.62 +/- 10.60% and Cmax was 0.732 +/- 0.05 mg/L. At 12 hours after IM administration, plasma creatine kinase activity had increased 7-fold, compared with the preinjection value. CONCLUSIONS AND CLINICAL RELEVANCE: Data suggest that difloxacin is likely to be effective for treating susceptible bacterial infections in horses.  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