scholarly journals Pharmacokinetics of danofloxacin in African catfish (Clarias gariepinus) after intravenous and intramuscular administrations

2019 ◽  
Vol 67 (4) ◽  
pp. 602-609
Author(s):  
Mohamed Aboubakr ◽  
Ahmed Soliman

The plasma pharmacokinetics of danofloxacin was studied in healthy African catfish (Clarias gariepinus) following a single intravenous (IV) and intramuscular (IM) administration of 10 mg/kg at 22 °C. Catfish were divided into two groups (each group containing 78 fish), then danofloxacin mesylate (10 mg/kg) was administered IV (into the caudal vein) in Group 1 and IM (into the right epaxial muscle) in Group 2, and blood was obtained from the caudal vein before (0 h) and after (0.25, 0.5, 1, 2, 4, 8, 12, 24, 36, 48, 72 and 96 h) of drug administration. High-performance liquid chromatography was used for the determination of plasma concentration, and a non-compartmental model was used for the analysis of pharmacokinetic parameters. After IV administration, elimination half-life (t1/2λz, 24.49 h), mean residence time (MRT, 30.14 h), volume of distribution at steady state (Vdss, 1.07 L/kg) and total body clearance (CLT, 0.035 L/h/kg) were determined. After IM administration, t1/2λz, MRT, peak concentration (Cmax), time to reach Cmax and bioavailability were 47.64 h, 61.06 h, 5.22 µg/mL, 1 h and 67.12%, respectively. After IM administration, danofloxacin showed good bioavailability and long t1/2λz. The favourable pharmacokinetic characteristics after IM administration support the use of danofloxacin for the treatment of susceptible bacterial infections in catfish.

2001 ◽  
Vol 45 (1) ◽  
pp. 181-186 ◽  
Author(s):  
Timothy M. E. Davis ◽  
Hoang Lan Phuong ◽  
Kenneth F. Ilett ◽  
Nguyen Canh Hung ◽  
Kevin T. Batty ◽  
...  

ABSTRACT To provide novel data relating to the dispositions, effects, and toxicities of the artemisinin derivatives in severe malaria, we studied 30 Vietnamese adults with slide-positive falciparum malaria treated with intravenous artesunate. Twelve patients with complications (severe; group 1) and 8 patients without complications but requiring parenteral therapy (moderately severe; group 2) received 120 mg of artesunate by injection, and 10 patients with moderately severe complications (group 3) were given 240 mg by infusion. Serial concentrations of artesunate and its active metabolite dihydroartemisinin in plasma were measured by high-performance liquid chromatography. The time to 50% parasite clearance (PCT50) was determined from serial parasite densities. Full clinical (including neurological) assessments were performed at least daily. In noncompartmental pharmacokinetic analyses, group mean artesunate half-lives (t 1/2) were short (range, 2.3 to 4.3 min). The dihydroartemisinin t 1/2 (range, 40 to 64 min), clearance (range, 0.73 to 1.01 liters/h/kg), and volume of distribution (range, 0.77 to 1.01 liters/kg) were also similar both across the three patient groups (P > 0.1) and to previously reported values for patients with uncomplicated malaria. Parasite clearance was prompt (group median PCT50 range 6 to 9 h) and clinical recovery was complete under all three regimens. These data indicate that the pharmacokinetics of artesunate and dihydroartemisinin are not influenced by the severity of malaria. Since the pharmacokinetic parameters for both artesunate and dihydroartemisinin were similar regardless of whether injection or infusion was used, artesunate can be considered a prodrug that is converted stoichiometrically to dhydroartemisinin. Conventional doses of artesunate are safe and effective when given to patients with complications of falciparum malaria.


2002 ◽  
Vol 46 (5) ◽  
pp. 1357-1363 ◽  
Author(s):  
Heng Song ◽  
George W. Griesgraber ◽  
Carston R. Wagner ◽  
Cheryl L. Zimmerman

ABSTRACT In vitro studies have demonstrated that water-soluble, nontoxic phosphoramidates of azidothymidine (zidovudine [AZT]) have significant and specific anti-human immunodeficiency virus and anticancer activity. Although polar, these compounds are internalized and processed to the corresponding nucleoside monophosphates. Eight methyl amide and methyl ester phosphoramidate monoesters composed of d- or l-phenylalanine or tryptophan and AZT were synthesized. The plasma stability and protein binding studies were carried out in vitro. Then in vivo pharmacokinetic evaluations of six of the compounds were conducted. Sprague-Dawley rats received each compound by intravenous bolus dose, and serial blood and urine samples were collected. AZT and phosphoramidate concentrations in plasma and urine were quantitated by high-performance liquid chromatography with UV or fluorescence detection. Pharmacokinetic parameters were calculated by standard noncompartmental means. The plasma half-lives of the phosphoramidates were 10- to 20-fold longer than the half-life of AZT. Although the renal clearances of the phosphoramidates were similar to AZT, their total body clearances were significantly greater than that of AZT. The 3- to 15-fold-larger volume of distribution (V ss) for the phosphoramidates relative to AZT appeared to be dependent on the stereochemistry of the amino acid, with the largest values being associated with the l-amino acids. The increased V ss indicates a much greater tissue distribution of the phosphoramidate prodrugs than of AZT. Amino acid phosphoramidate monoesters of AZT have improved pharmacokinetic properties over AZT and significant potential as in vivo pronucleotides.


2004 ◽  
Vol 48 (1) ◽  
pp. 281-284 ◽  
Author(s):  
John A. Bosso ◽  
Patrick A. Flume ◽  
Susan L. Gray

ABSTRACT The pharmacokinetics of many drugs are altered in patients with cystic fibrosis (CF), often necessitating different dosage requirements than those used in non-CF patients. The objective of this study was to determine the pharmacokinetics of linezolid, an antibiotic with good activity against gram-positive organisms such as methicillin-resistant Staphylococcus aureus, in patients with CF so that dosage requirements could be established. Twelve adult patients (6 male) ranging in age from 22 to 39 years were studied. A single 600-mg dose was administered intravenously over 0.5 h, and plasma samples were collected at 0 (predose), 0.5, 0.75, 1, 2, 4, 8, and 24 h. Linezolid concentrations were determined with a validated high-performance liquid chromatography assay. Pharmacokinetic parameters were estimated using standard noncompartmental methods. Blood chemistry and hematologic indices were determined before and after the study for safety purposes. All patients completed the study without encountering any adverse reactions. The pharmacokinetic parameters, while variable, with half-lives varying from 1.76 to 8.36 h, were similar to those previously described in other populations. Mean (± standard deviation) values for pharmacokinetic parameters of interest were as follows: elimination rate constant, 0.21 (0.11) h−1; half-life, 4.41 (2.43); volume of distribution at steady state, 0.87 (0.19) liters/kg of body weight; and total body clearance, 0.12 (0.06) liters/h/kg. No patient would have achieved the pharmacodynamic target of an area under the concentration-time curve/MIC ratio of 83 h for pathogens for which the MIC was 4 μg/ml. Patients with inadequate clinical responses to linezolid may require more frequent dosing.


2011 ◽  
Vol 55 (6) ◽  
pp. 2927-2936 ◽  
Author(s):  
J. B. Bulitta ◽  
M. Kinzig ◽  
C. B. Landersdorfer ◽  
U. Holzgrabe ◽  
U. Stephan ◽  
...  

ABSTRACTCystic fibrosis (CF) patients are often reported to have higher clearances and larger volumes of distribution per kilogram of total body weight (WT) for beta-lactams than healthy volunteers. As pharmacokinetic (PK) data on cefpirome from studies of CF patients are lacking, we systematically compared its population PK and pharmacodynamic breakpoints for CF patients and healthy volunteers of similar body size. Twelve adult CF patients (median lean body mass [LBM] = 45.7 kg) and 12 healthy volunteers (LBM = 50.0 kg) received a single 10-min intravenous infusion of 2 g cefpirome. Plasma and urine concentrations were determined by high-performance liquid chromatography (HPLC). Population PK and Monte Carlo simulations were performed using NONMEM and S-ADAPT and a duration of an unbound plasma concentration above the MIC ≥ 65% of the dosing interval as a pharmacodynamic target. Unscaled clearances for CF patients were similar to those seen with healthy volunteers, and the volume of distribution was 6% lower for CF patients. Linear scaling of total clearance by WT resulted in clearance that was 20% higher (P≤ 0.001 [nonparametric bootstrap]) in CF patients. Allometric scaling by LBM explained the differences between the two subject groups with respect to average clearance and volume of distribution and reduced the unexplained between-subject variability of renal and nonrenal clearance by 10 to 14%. For the CF patients, robust (>90%) probabilities of target attainment (PTA) were achieved by the administration of a standard dose of 2 g/70 kg WT every 12 h (Q12h) given as 30-min infusions for MICs ≤ 1.5 mg/liter. As alternative dosage regimens, a 5-h infusion of 1.33 g/70 kg WT Q8h achieved robust PTAs for MICs ≤ 8 to 12 mg/liter and a continuous infusion of 4 g/day for MICs ≤ 12 mg/liter. Prolonged infusion of cefpirome is expected to be superior to short-term infusions for MICs between 2 and 12 mg/liter.


2009 ◽  
Vol 53 (8) ◽  
pp. 3266-3268 ◽  
Author(s):  
Kook-Hwan Oh ◽  
Chiweon Kim ◽  
Hankyu Lee ◽  
Hajeong Lee ◽  
Ji Yong Jung ◽  
...  

ABSTRACT The pharmacokinetic characteristics of piperacillin sodium were studied in five volunteers undergoing on-line hemodiafiltration (HDF). The subjects were given 2 g of piperacillin sodium intravenously over 1 min and placed on on-line HDF for 4 h starting at 60 min after the piperacillin infusion. Noncompartmental models were employed for estimation of the pharmacokinetic parameters, and intradialytic piperacillin clearance was calculated by the recovery method. The mean volume of distribution and the elimination half-life were 0.27 ± 0.13 liter/kg (mean ± standard deviation) and 1.1 ± 0.6 h, respectively. The total body clearance of piperacillin was 0.19 ± 0.08 liter/h/kg. Piperacillin clearance through on-line HDF was 0.11 ± 0.06 liter/h/kg. The mean serum piperacillin concentration was 4.0 ± 1.9 μg/ml at the end of the 4-h on-line HDF session. The concentration of infused piperacillin recovered in the dialysate was 527 ± 236 mg (26.3% ± 11.8%). We suggest the replacement of 500 mg of piperacillin after each on-line HDF session.


Author(s):  
Ryan D Dunn ◽  
Ryan L Crass ◽  
Joseph Hong ◽  
Manjunath P Pai ◽  
Lynne C Krop

Abstract Purpose To compare methods of estimating vancomycin volume of distribution (V) in adults with class III obesity. Methods A retrospective, multicenter pharmacokinetic analysis of adults treated with vancomycin and monitored through measurement of peak and trough concentrations was performed. Individual pharmacokinetic parameter estimates were obtained via maximum a posteriori Bayesian analysis. The relationship between V and body weight was assessed using linear regression. Mean bias and root-mean-square error (RMSE) were calculated to assess the precision of multiple methods of estimating V. Results Of 241 patients included in the study sample, 159 (66.0%) had a BMI of 40.0–49.9 kg/m2, and 82 (34.0%) had a BMI of ≥50.0 kg/m2. The median (5th, 95th percentile) weight of patients was 136 (103, 204) kg, and baseline characteristics were similar between BMI groups. The mean ± S.D. V was lower in patients with a BMI of 40.0–49.9 kg/m2 than in those with a BMI of ≥50.0 kg/m2 (72.4 ± 19.6 L versus 79.3 ± 20.6 L, p = 0.009); however, body size poorly predicted V in regression analyses (R2 < 0.20). A fixed estimate of V (75 L) or use of 0.52 L/kg by total body weight yielded similar bias and error in this population. Conclusion Results of the largest analysis of vancomycin V in class III obesity to date indicated that use of a fixed V value (75 L) and use of a TBW-based estimate (0.52 L/kg) for estimation of vancomycin V in patients with a BMI of ≥40.0 kg/m2 have similar bias. Two postdistribution vancomycin concentrations are needed to accurately determine patient-specific pharmacokinetic parameters, estimate AUC, and improve the precision of vancomycin dosing in this patient population.


2001 ◽  
Vol 45 (2) ◽  
pp. 596-600 ◽  
Author(s):  
Andreas H. Groll ◽  
Bryan M. Gullick ◽  
Ruta Petraitiene ◽  
Vidmantas Petraitis ◽  
Myrna Candelario ◽  
...  

ABSTRACT The pharmacokinetics of the antifungal echinocandin-lipopeptide caspofungin (MK-0991) in plasma were studied in groups of three healthy rabbits after single and multiple daily intravenous administration of doses of 1, 3, and 6 mg/kg of body weight. Concentrations were measured by a validated high-performance liquid chromatography method and fitted into a three-compartment open pharmacokinetic model. Across the investigated dosage range, caspofungin displayed dose-independent pharmacokinetics. Following administration over 7 days, the mean peak concentration in plasma (C max) ± standard error of the mean increased from 16.01 ± 0.61 μg/ml at the 1-mg/kg dose to 105.52 ± 8.92 μg/ml at the 6-mg/kg dose; the mean area under the curve from 0 h to infinity rose from 13.15 ± 2.37 to 158.43 ± 15.58 μg · h/ml, respectively. The mean apparent volume of distribution at steady state (Vdss) was 0.299 ± 0.011 liter/kg at the 1-mg/kg dose and 0.351 ± 0.016 liter/kg at the 6-mg/kg dose (not significant [NS]). Clearance (CL) ranged from 0.086 ± 0.017 liter/kg/h at the 1-mg/kg dose to 0.043 ± 0.004 liter/kg/h at the 6-mg/kg dose (NS), and the mean terminal half-life was between 30 and 34 h (NS). Except for a trend towards an increasedVdss, there were no significant differences in pharmacokinetic parameters in comparison to those after single-dose administration. Caspofungin was well tolerated, displayed linear pharmacokinetics that fit into a three-compartment pharmacokinetic model, and achieved sustained concentrations in plasma that were multiple times in excess of reported MICs for susceptible opportunistic fungi.


2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S651-S652
Author(s):  
Ronaldo Morales ◽  
Vanessa D Juodinis ◽  
Daniela Carla de Souza ◽  
Silvia Regina C Jorge Santos

Abstract Background Vancomycin is largely prescribed to treat gram-positive bacterial infections in pediatric patients after liver transplantation with the same empirical doses prescribed in other critical conditions due to the absence of pharmacokinetic studies in this population. The objective of this investigation was to describe the vancomycin pharmacokinetic parameters and to assess the vancomycin percentage of target attainment with empirical regimen. Methods Prospective and longitudinal study with pediatric post-liver transplantation patients who received at least 48 hours of vancomycin between January 2020 and May 2021. Patients with acute or chronic renal failure or receiving renal replacement therapy were excluded. Vancomycin therapy started with 40-60mg/kg daily, one-hour infusion. The pharmacokinetic parameters were determined by one-compartment model with first-order kinetics using near steady-state postdistributional peak and trough within the same dosing interval. Therapeutic target was defined as vancomycin 24-hour area under the curve/minimum inhibitory concentration (AUCss0-24/MIC) ≥ 400 and &lt; 600. The study protocol was approved by the local ethics committee. Results We included 18 sets of peak/trough serum concentrations obtained from 12 patients. The patients had median age of 11 (interquartile range [IQ] 8-16) months. The found vancomycin clearance, volume of distribution and half-life values were, respectively, 2.1 (IQ 1.4-2.8) mL/kg/min, 0.6 (IQ 0.5-0.7) L/kg and 3.2 (IQ 2.3-4.0) hours. After the initial dose regimen, 5 (42%) patients reached the therapeutic target. Conclusion Using the one-compartment model, we evaluate the pharmacokinetic parameters of vancomycin in pediatric patients after liver transplantation. Most of patients did not reach the therapeutic target with empirical regimen, so it is prudent to monitor the exposure to vancomycin directly by AUC/MIC ratio to maximize antimicrobial efficacy. Disclosures All Authors: No reported disclosures


1970 ◽  
Vol 6 (1) ◽  
pp. 93-97
Author(s):  
MS Islam ◽  
MMH Sikder ◽  
MA Awal ◽  
M Mostofa ◽  
AA Trisha

The study was carried out to determine the biodisposition kinetics of ciprofloxacin in sheep model in Department of Pharmacology, Bangladesh Agricultural University. Healthy sheep of both sexes (n=65) were divided into 13 groups, each consists of five and given a single dose of ciprofloxacin @ 5 mg/kg bwt intramuscularly .Blood sample was collected from each group of sheep at 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 6, 8, 10 and 12 hours interval respectively. Serum concentration of ciprofloxacin was determined by spectrophotometric method. The pharmacokinetic parameters were measured by single compartment open model and first order kinetics. The peak concentration of ciprofloxacin was 3.56±0.15mg/ ml, absorption half-life and biological half-life were 0.0846±1.79 and 1.75±0.15 h respectively. The apparent volume of distribution was found 35.54 mg/liter. The absorption rate constant was 8.188h-1, MRT was 2.647h-1 and total body clearances were found 16.88 h-1. These result suggested that a dose of 5 mg/kg bwt provides maximum plasma concentration and is effective in the control of many infectious diseases of sheep. Key words: Plasma pharmacokinetics, ciprofloxacin, sheep DOI = 10.3329/bjvm.v6i1.1344 Bangl. J. Vet. Med. (2008). 6 (1): 93-97


2010 ◽  
Vol 13 (3) ◽  
pp. 443 ◽  
Author(s):  
Tao Guo ◽  
Longshan Zhao ◽  
Dong-Ya Xia

Purpose. The pharmacokinetics of modafinil were investigated in relation to gender and ethnicity in healthy young volunteers from Han, Mongolian, Korean, Uygur and Hui ( n = 10/group) following administration of a single 200 mg oral dose. Methods. Blood samples were collected over 48 h for the determination of plasma levels of modafinil and its acid metabolite by High performance liquid chromatography with an ultraviolet detector. Pharmacokinetic parameters were evaluated using noncompartmental methods. Results. Modafinil was well tolerated and safe at a single oral dose of 200 mg. All participants reported adverse events, none of which was serious or unexpected. The maximum plasma concentration (Cmax) and area under the curve for modafinil concentration versus time, which was extrapolated to infinity (AUC0-∞), were higher in women compared to men (p < 0.01). No gender-based difference was noted in the total body weight-normalized modafinil oral clearance. The total body weight-normalized modafinil apparent volume of distribution and the t1/2 was found to exhibit an ethnicity-based significant difference. Conclusion. The results of the current study suggest that there might be pharmacokinetic differences related to gender and ethnicity in the pharmacokinetics of modafinil.


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