Pharmacokinetics and Tissue Distribution of Norfloxacin in Eel Following Oral Gavage

2012 ◽  
Vol 452-453 ◽  
pp. 1069-1073
Author(s):  
Yun Hua Hui ◽  
You Qiong Cai ◽  
Bing Feng ◽  
Wen Ruan ◽  
Hui Juan Yu

The pharmacokinetics of norfloxacin were investigated in the European eel after a single oral gavage of 10 mg norfloxacin per kg body weight. The concentrations of norfloxacin in the main tissues (kidney, muscle, hepatopancreas and blood) were simultaneously detected by HPLC. All of the concentration-time curves of norfloxacin in the plasma, muscle and liver were consistent with absorption of a two-compartment open kinetic model. Norfloxacin was widely distributed in different tissues in the European eel. Apparent volume of distribution (Vd) was 52.025 L/kg, 34.589 L/kg, 2.795 L/kg, and 0.969 L/kg, in plasma, muscle, liver and kidney, respectively. Norfloxacin in the eel was proved to eliminate slowly, and half-time (tβ1/2) in plasma, muscle, liver and kidney, was 201.222 h, 123.789 h, 120.634 h and 627473.495 h, respectively. Body clearance was 0.689 L / ( kg•h ), 1.793 L/( kg•h ), 0.097 L/( kg•h ) and 0.028 L /( kg•h ), in plasma, muscle, liver and kidney, respectively.

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Weina Ma ◽  
Lei Lv ◽  
Jungang Guo ◽  
Yongjun Meng ◽  
Yinghua Wang ◽  
...  

The aim of this study was to examine whether Xuesaitong, a multiherbal formulation for coronary heart disease, alters the pharmacokinetics of losartan. Adult male Sprague Dawley rats randomly received losartan (10 mg/kg) or losartan plus Xuesaitong (10 mg/kg) through an oral gavage (n = 6). Multiple blood samples were obtained for up to 36 h to determine the concentrations of losartan and its active metabolite, EXP3174, through ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Pharmacokinetics were estimated using a noncompartmental model. The half-life (t1/2) of losartan was decreased by Xuesaitong (4.26 ± 1.51 vs. 6.35 ± 2.10 h; P<0.05). The apparent volume of distribution (Vd) of losartan was also decreased by the combination of losartan and Xuesaitong (4.41 ± 1.61 vs. 7.20 ± 2.41 mL; P<0.05). The time to maximum concentration (Tmax) of losartan was increased by Xuesaitong (1.06 ± 1.04 vs. 0.13 ± 0.05 h; P<0.05). Xuesaitong also decreased the t1/2 of EXP3174 (8.22 ± 1.41 vs. 6.29 ± 1.38 h; P<0.05). These results suggest that there is a complex interaction between losartan and Xuesaitong. In addition to enhanced elimination of losartan and EXP3174, Xuesaitong may also decrease the absorption rate and Vd of losartan.


1986 ◽  
Vol 20 (9) ◽  
pp. 704-707 ◽  
Author(s):  
Maria J. Otero ◽  
Miguel Barrueco ◽  
Eduardo L. Marino ◽  
Francisco Gomez ◽  
Alfonso Dominguez-Gil

The influence of age on the disposition of theophylline was studied in 95 adult patients (nonsmokers) with bronchial asthma requiring oral theophylline therapy: 17 patients age ≥39 years, 50 patients age 40–59 years, and 28 patients < 60 years. A decrease was observed in total body clearance together with an increase in the elimination half-life of theophylline parallel to the advance in age of the patients. The apparent volume of distribution of theophylline was similar in the three groups of patients. According to the results obtained, recommendations are made regarding the dosage regimens of theophylline in elderly patients.


1969 ◽  
Vol 43 (2) ◽  
pp. 175-189 ◽  
Author(s):  
MIRIAM FABIAN ◽  
MARY L. FORSLING ◽  
J. J. JONES ◽  
J. LEE

SUMMARY At 4°, the activity of exogenous 8-arginine vasopressin in rat plasma decreased to 50% in 2 days, whereas there was no loss of oxytocin under the same conditions after 3 days. At 37°, oxytocin was not inactivated in 9 hr., whereas 50% of 8-arginine vasopressin was lost in 2 hr. Forty per cent of exogenous oxytocin in rat plasma was unable to pass through a cellophane (Visking 8/32 in.) membrane, when subjected to a pressure of 100 torr for 18 hr. In rats under pentobarbitone anaesthesia, progressive haemorrhage of more than 2·0 ml./100 g. induced a secretion of both oxytocin and 8-arginine vasopressin, to produce maximum concentrations of 450 and 700 μ-u./ml., respectively, in the carotid plasma. In the intact rat (weighing 200–250 g.) anaesthetized with pentobarbitone, 50% of oxytocin in the circulation disappeared within 2 min. after stopping an i.v. infusion of 250–6000 μ-u./100 g./min. The half-time was increased to 4 min. by sham operation, and to 6 or 7 min. by occluding either the renal, or the portal, coeliac and mesenteric vessels. In non-lactating animals, the half-time was 8 min. after clamping both the renal and splanchnic vessels, whereas it was 6 min. in the lactating rat, under the same conditions. The apparent volume of distribution of oxytocin was 7·3 ml./100 g. in intact rats, and 10–13 ml./100 g. after operation. The plasma clearance of oxytocin was unaltered in the sham-operated rat, but it decreased after the operative procedures.


PEDIATRICS ◽  
1980 ◽  
Vol 66 (4) ◽  
pp. 579-584
Author(s):  
Carolyn M. Sack ◽  
Jeffrey R. Koup ◽  
Arnold L. Smith

We measured serum chloramphenicol concentrations in 17 hospitalized pediatric patients (aged 1 month to 6 years) after intravenous infusion of chloramphenicol succinate. The serum T½ ranged from 2.1 to 8.3 hours with a mean of 3.98 (SD 1.75) hours, while the apparent volume of distribution ranged from 0.78 to 2.09 liters/kg with a mean of 1.39 (SD 0.34) liters/kg. The total body clearance ranged 0.122 to 0.429 liters/kg/hour with a mean of 0.281 (SD 0.117) liters/kg/hour. Two patients were restudied, and had increased clearance during their hospitalization. Because of the wide variability in pharmacokinetics, we conclude that serum chloramphenicol concentrations should be monitored in infants and children.


1979 ◽  
Vol 57 (8) ◽  
pp. 878-881 ◽  
Author(s):  
James E. Heavner ◽  
Duane C. Bloedow

Pharmacokinetic parameters of a ketamine (10 mg/kg, iv) bolus in decerebrate and intact cats were compared. A two-compartment open model best described the data in both groups. The apparent volume of distribution of the peripheral compartment, the apparent volume of distribution of the drug in the body, and the half-life of the postdistributive phase were significantly less (p < 0.05) in the decerebrate animals. These results emphasize the importance of correlating behavior and neuronal activity with plasma or blood concentrations of drug in animals rather than assuming that, for a given drug dose, blood (and thus tissue) levels of the agent will be similar regardless of how the animal is prepared for study.


PEDIATRICS ◽  
1981 ◽  
Vol 68 (4) ◽  
pp. 601-602
Author(s):  
M. Spino ◽  
J. J. Thiessen ◽  
A. Isles ◽  
H. Levison ◽  
S. M. MacLeod

We found the report by Feldman et al1 interesting with potential clinical application. However, we would like to point out an error in their determination of the apparent volume of distribution (V) and comment on both their methodology and results. They state that V was calculated by dividing the dose of the drug by the extrapolated y intercept for drug concentration at time 0. This method is correct for a drug which exhibits monoexponential elimination following a single intravenous dose.


Author(s):  
Hisham S. Abou-Auda ◽  
Eqbal Qaddour ◽  
Hussein Alsisi ◽  
Azizah Ajlan ◽  
Mohammad Alsebayel

Introduction: Tacrolimus is a macrolide immunosuppressant. It has a narrow therapeutic index and serious side effects which necessitate monitoring of tacrolimus blood concentration. The trough concentration of the drug may also differ based on the type of liver transplant. This study was conducted to investigate differences in pharmacokinetics between transplant types and to determine tacrolimus population pharmacokinetic in liver transplant recipients in Saudi Arabia. Method: Patients on tacrolimus, as the main immunosuppressant, who underwent liver transplant throughout2012-2014 were retrospectively studied. Demographic characteristic, tacrolimus blood trough concentrations, liver, renal, biochemistry, and hematology lab results were all collected. The pharmacokinetic parameters were estimated assuming one compartment model. Results: Tacrolimus pharmacokinetic parameters were found to be as following; elimination rate constant () 0.094 ±  0.0123, apparent volume of distribution () 112.48±63.033 L/hr, elimination half-life () 7.46± 1.01 hr and apparent total body clearance () 10.27± 5.69 L/hr (mean ± SD). Statistically significant difference was found between living-donor and deceased-donor liver transplant with respect to apparent clearance and apparent volume of distribution. Living-donor liver transplant recipients have apparent volume of distribution of 97.39±47.00 L (mean ± SD) and an apparent clearance of 8.89±4.24L/hr (mean± SD). On the other hand, deceased-donor liver transplant has an apparent clearance of 12.97±7.09L/hr (mean ± SD) and an apparent volume of distribution of 142.17± 78.65 L (mean ± SD). Conclusions: Tacrolimus pharmacokinetics parameters were accurately determined in liver transplant recipients in Saudi Arabia. The results of the present study can be clinically used in the therapeutic drug monitoring of tacrolimus in the individualization of drug dosage and taking the appropriate clinical decisions to prevent allograft rejection.


PEDIATRICS ◽  
1981 ◽  
Vol 68 (4) ◽  
pp. 602-603
Author(s):  
Charles H. Feldman ◽  
Vincent E. Hutchinson ◽  
Charles E. Pippenger ◽  
Thomas A. Blumenfeld ◽  
Bernard R. Feldman ◽  
...  

We appreciate the comments of Weinberger et al and Spino et al. The equation utilized in our original report to calculate the apparent volume of distribution (V) was in error, as it was based on determinations for drugs that exhibit monoexponential elimination following a single intravenous dose. The correct formula for oral dosing at steady state with a drug obeying one-compartment model kinetics is: V = F.X0/AUCτ. K, where F is the total fraction of dose reaching systemic circulation, X0, is the dose, AUCτ is the area under the curve during a dosing interval; K is the elimination rate constant.1


PEDIATRICS ◽  
1974 ◽  
Vol 54 (6) ◽  
pp. 713-717
Author(s):  
Gerhard Levy ◽  
Sumner J. Yaffe

The apparent volume of distribution (Vd) of salicylate was determined in 11 children, 4 months to 16 years old, who had ingested from about 36 to over 340 mg of salicylic acid (mainly as aspirin) per kilogram of body weight. Vd was calculated from the amount of salicylate in the body at a given time (as determined by the amount of total salicylates excreted in the urine and, where applicable, removed in peritoneal dialysis fluid after that time) and the concentration of salicylate in the plasma at the same time. This method of calculation is ideal for the nonlinearly eliminated salicylic acid and does not require any assumptions with respect to the nature of the pharmacokinetic model for salicylate distribution. The Vd for salicylate in the children ranged from 162 to 345 ml/kg and was larger at the higher doses. Plots of salicylate concentration in plasma versus amount of drug in the body were usually linear for a given patient, showing that Vd remained relatively constant over the time course of elimination of the drug in the patients studied. This indicates that a given plasma salicylate concentration in children who have ingested large doses reflects a larger amount of salicylate in the body than the same plasma concentration in children who ingested smaller doses of the drug. These observations help to rationalize and emphasize the usefulness of the Done nomogram (which involves estimation of the theoretical zero time plasma salicylate concentration by back extrapolation) for assessing the severity of salicylate intoxication.


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