scholarly journals Domestic Cat Model for Predicting Human Nucleoside Analogue Pharmacokinetics in Blood and Seminal Plasma

2001 ◽  
Vol 45 (7) ◽  
pp. 2173-2176 ◽  
Author(s):  
Holly L. Jordan ◽  
Arlene S. Pereira ◽  
Myron S. Cohen ◽  
Angela D. M. Kashuba
Keyword(s):  
Seminal Plasma ◽  
Nucleoside Analogue ◽  
Domestic Cat ◽  
Pharmacokinetic Parameters ◽  
Time Curve ◽  
Concentration Time ◽  
Feline Model ◽  
Cat Model ◽  
Male Genital

ABSTRACT To establish whether a feline model can predict nucleoside analogue behavior in human semen, zidovudine (ZDV) and lamivudine (3TC) pharmacokinetic parameters (PKs) were determined in the blood and seminal plasma of healthy cats. Our results show considerable similarity in ZDV and 3TC PKs between cats and humans. As in humans, ZDV and 3TC tend to accumulate in feline seminal plasma. Area under the blood plasma concentration-time curve was predictive of seminal plasma excretion. The felid model offers a unique in vivo experimental alternative for investigating the pharmacokinetics of nucleoside analogues in the male genital tract.

scholarly journals Effects of Silymarin on the In Vivo Pharmacokinetics of Simvastatin and Its Active Metabolite in Rats

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1666
Author(s):  
Ying Li ◽  
Yin Wu ◽  
Ya-Jing Li ◽  
Lu Meng ◽  
Cong-Yang Ding ◽  
...  
Keyword(s):  
Active Metabolite ◽  
Compartmental Model ◽  
Elimination Rate ◽  
Pharmacokinetic Parameters ◽  
Time Curve ◽  
Simultaneous Quantification ◽  
Concentration Time ◽  
Significant Difference ◽  
In Vivo Pharmacokinetics

Herein, the effect of silymarin pretreatment on the pharmacokinetics of simvastatin in rats was evaluated. To ensure the accuracy of the results, a rapid and sensitive UPLC–MS/MS method was established for simultaneous quantification of simvastatin (SV) and its active metabolite simvastatin acid (SVA). This method was applied for studying the pharmacokinetic interactions in rats after oral co-administration of silymarin (45 mg/kg) and different concentrations of SV. The major pharmacokinetic parameters, including Cmax, tmax, t1/2, mean residence time (MRT), elimination rate constant (λz) and area under the concentration-time curve (AUC0–12h), were calculated using the non-compartmental model. The results showed that the co-administration of silymarin and SV significantly increased the Cmax and AUC0–12h of SVA compared with SV alone, while there was no significant difference with regards to Tmax and t1/2. However, SV pharmacokinetic parameters were not significantly affected by silymarin pretreatment. Therefore, these changes indicated that drug-drug interactions may occur after co-administration of silymarin and SV.

scholarly journals Comparative Assessment of Tedizolid Pharmacokinetics and Tissue Penetration between Diabetic Patients with Wound Infections and Healthy Volunteers via In Vivo Microdialysis

2017 ◽  
Vol 62 (1) ◽  
Author(s):  
Sean M. Stainton ◽  
Marguerite L. Monogue ◽  
Arlinda Baummer-Carr ◽  
Ashley K. Shepard ◽  
James F. Nugent ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Subcutaneous Tissue ◽  
Extracellular Fluid ◽  
Pharmacokinetic Parameters ◽  
Diabetic Patients ◽  
Tissue Penetration ◽  
Time Curve ◽  
Dosing Interval ◽  
Concentration Time

ABSTRACT Herein, we present pharmacokinetic and tissue penetration data for oral tedizolid in hospitalized patients with diabetic foot infections (DFI) compared with healthy volunteers. Participants received oral tedizolid phosphate 200 mg every 24 h for 3 doses to achieve steady state. A microdialysis catheter was inserted into the subcutaneous tissue near the margin of the wound for patients or into thigh tissue of volunteers. Following the third dose, 12 blood and 14 dialysate fluid samples were collected over 24 h to characterize tedizolid concentrations in plasma and interstitial extracellular fluid of soft tissue. Mean ± standard deviation (SD) tedizolid pharmacokinetic parameters in plasma for patients compared with volunteers, respectively, were as follows: maximum concentration (C max), 1.5 ± 0.5 versus 2.7 ± 1.1 mg/liter (P = 0.005); time to C max (T max) (median [range]), 5.9 (1.2 to 8.0) versus 2.5 (2.0 to 3.0 h) (P = 0.003); half-life (t1/2), 9.1 ± 3.6 versus 8.9 ± 2.2 h (P = 0.932); and plasma area under the concentration-time curve for the dosing interval (AUC p ), 18.5 ± 9.7 versus 28.7 ± 9.6 mg · h/liter (P = 0.004). The tissue area under the concentration-time curve (AUC t ) for the dosing interval was 3.4 ± 1.5 versus 5.2 ± 1.6 mg · h/liter (P = 0.075). Tissue penetration median (range) was 1.1 (0.3 to 1.6) versus 0.8 (0.7 to 1.0) (P = 0.351). Despite lower plasma C max and delayed T max values for patients with DFI relative to healthy volunteers, the penetration into and exposure to tissue were similar. Based on available pharmacodynamic thresholds for tedizolid, the plasma and tissue exposures using the oral 200 mg once-daily regimen are suitable for further study in treatment of DFI.

scholarly journals A Rapid and Sensitive UHPLC-MS/MS Method for Determination of 2, 3, 8-Trimethylellagic, a Potent Active Compound from Sanguisorba officinalis L., and Its Application in the Pharmacokinetic Study within Thrombocytopenia Rats

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yuqing Wang ◽  
Jianming Wu ◽  
Yunxia Li ◽  
Jing Yang ◽  
Long Wang ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Maximum Concentration ◽  
High Performance ◽  
Internal Standard ◽  
Pharmacokinetic Parameters ◽  
Time Curve ◽  
Concentration Time ◽  
Relative Standard ◽  
Plasma Concentration Time Curve

To investigate the pharmacokinetics of 2, 3, 8-trimethylellagic (TMEA) in rats in vivo and determine the possible effects of the pathological conditions and compatibility, a rapid and sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for quantitative determination was developed. TMEA and Artemetin (internal standard, IS) were separated on an Acquity Shim-pack GIST column with a total running time of 7 min using gradient elution at a flow rate of 0.3 mL/min. The intraday and interday relative standard deviations were <9.50%, and the relative error of accuracy was between −5.70% and 2.96%. The calibration curve of TMEA demonstrated good linearity with r2 = 0.9996, with the average recovery changing from 94.77% to 102.47% and the matrix effect from 93.16% to 100.15%. Compared with the normal group, the area under the plasma concentration-time curve from time 0 to the last time of quantifiable concentration (AUC(0 − t)), area under the plasma concentration-time curve from time 0 extrapolated to infinite time (AUC(0 − ∞)), and the maximum concentration (Cmax) of TMEA increased, whereas the time of maximum concentration (Tmax) and apparent clearance (CL/F) remarkably decreased in the TMEA group. With significantly reduced CL/F, AUC(0 − t), AUC(0 − ∞), and Cmax for TMEA were increased approximately one time after combining with 3, 7-Di-O-methylducheside A (DOMA). AUC(0 − t) and Cmax for TMEA in the 2, 3, 8-trimethylellagic-3, 8-dimethoxyellagic acid-2-oxyglucoside (TMEA-DMAG) group were significantly lower than that in the TMEA group with clearly prolonged Tmax and increased CL/F. These findings indicate that the changes in the pharmacokinetic parameters of TMEA may be caused by pathological and combination conditions.

A Comparative Pharmacokinetic Profile of Trahydropalmatine After Oral Administration of its Monomer, Rhizoma Corydalis Alkaloid Extracts and Tong-Bi-Si-Wei-Fang to Rats

2019 ◽  
Vol 15 (4) ◽  
pp. 338-345
Author(s):  
Lijun Ni ◽  
Lu Ding ◽  
Liguo Zhang ◽  
Shaorong Luan
Keyword(s):  
Oral Administration ◽  
Panax Notoginseng ◽  
Pharmacokinetic Profile ◽  
Apparent Volume ◽  
Bone Diseases ◽  
Glycyrrhiza Uralensis ◽  
Pharmacokinetic Property ◽  
Time Curve ◽  
Concentration Time

Background: Tong-Bi-Si-Wei-Fang (TBSWF) is a candidate formula of Traditional Chinese Medicine (TCM) for treating rheumatoid bone diseases, which is composed of rhizoma corydalis alkaloids, saponins of glycyrrhiza uralensis and panax notoginseng, flavonoids of rhizoma drynariae and glycyrrhiza uralensis. </P><P> Objective: Trahydropalmatine (THP), the main active ingredient of rhizoma corydalis alkaloids, was selected to study in vivo pharmacokinetics and druggability of TBSWF. Methods: The plasma concentration-time (C-T) profiles of THP and the pharmacokinetic property parameters after oral administration of THP monomer, extract of corydalis alkaloids (ECA) and TBSWF to rats, respectively were compared by a fully-validated HPLC method. Results: Compared to the THP monomer, the THP in TBSWF is absorbed faster, resides in the plasma longer and has a similar apparent volume of distribution Vz/F (10~20 L/kg). Compared to THP monomer and THP in TBSWF, the area under the concentration-time curve AUC 0-t of THP in ECA decreases two-third; Vz/F of THP in ECA (85.02 L/kg) is significantly higher than that of THP in TBSWF(p <0.05). Unlike THP monomer and THP in ECA, double peaks are observed in the C-T profile of THP after oral administration of TBSWF. THP in TBSWF exhibits slow release to a certain degree. Conclusion: The interactions among the ingredients of TBSWF promote the adsorption and prolong the residence time of THP in vivo, and provide an explanation for the advantages of TBSWF from the point of pharmacokinetics.

scholarly journals Voriconazole Pharmacokinetics and Safety in Immunocompromised Children Compared to Adult Patients

2010 ◽  
Vol 54 (8) ◽  
pp. 3225-3232 ◽  
Author(s):  
Claudia Michael ◽  
Uta Bierbach ◽  
Katrin Frenzel ◽  
Thoralf Lange ◽  
Nadezda Basara ◽  
...  
Keyword(s):  
Pediatric Patients ◽  
Fungal Infections ◽  
Adult Patients ◽  
European Medicines Agency ◽  
Pharmacokinetic Parameters ◽  
Time Curve ◽  
Entire Study ◽  
Interindividual Variations ◽  
Concentration Time ◽  
Days Of Therapy

ABSTRACT The aim of this study was to investigate the pharmacokinetics and safety of voriconazole after intravenous (i.v.) administration in immunocompromised children (2 to 11 years old) and adults (20 to 60 years old) who required treatment for the prevention or therapy of systemic fungal infections. Nine pediatric patients were treated with a dose of 7 mg/kg i.v. every 12 h for a period of 10 days. Three children and 12 adults received two loading doses of 6 mg/kg i.v. every 12 h, followed by a maintenance dose of 5 mg/kg (children) or 4 mg/kg (adults) twice a day during the entire study period. Trough voriconazole levels in blood over 10 days of therapy and regular voriconazole levels in blood for up to 12 h postdose on day 3 were examined. Wide intra- and interindividual variations in plasma voriconazole levels were noted in each dose group and were most pronounced in the children receiving the 7-mg/kg dose. Five (56%) of them frequently had trough voriconazole levels in plasma below 1 μg/ml or above 6 μg/ml. The recommended dose of 7 mg/kg i.v. in children provides exposure (area under the concentration-time curve) comparable to that observed in adults receiving 4 mg/kg i.v. The children had significantly higher C max values; other pharmacokinetic parameters were not significantly different from those of adults. Voriconazole exhibits nonlinear pharmacokinetics in the majority of children. Voriconazole therapy was safe and well tolerated in pediatric and adult patients. The European Medicines Agency-approved i.v. dose of 7 mg/kg can be recommended for children aged 2 to <12 years.

Lack of Effect of Ginkgo biloba on Voriconazole Pharmacokinetics in Chinese Volunteers Identified as CYP2C19 Poor and Extensive Metabolizers

2009 ◽  
Vol 43 (4) ◽  
pp. 726-731 ◽  
Author(s):  
He-Ping Lei ◽  
Guo Wang ◽  
Lian-Sheng Wang ◽  
Dong-sheng Ou-yang ◽  
Hao Chen ◽  
...  
Keyword(s):  
Single Dose ◽  
Ginkgo Biloba ◽  
Poor Metabolizers ◽  
Pharmacokinetic Parameters ◽  
Extensive Metabolizers ◽  
Herbal Supplements ◽  
Time Curve ◽  
Concentration Time ◽  
Apparent Clearance ◽  
Randomized Crossover Study

Background: Ginkgo biloba is one of the most popular herbal supplements in the world. The supplement has been shown to induce the enzymatic activity of CYP2C19, the main cytochrome P450 isozyme involved in voriconazole metabolism. Because this enzyme exhibits genetic polymorphism, the inductive effect was expected to be modulated by the CYP2C19 metabolizer status. Objective: To examine the possible effects of Ginkgo biloba as an inducer of CYP2C19 on single-dose pharmacokinetics of voriconazole in Chinese volunteers genotyped as either CVP2C19 extensive or poor metabolizers. Methods: Fourteen healthy, nonsmoking volunteers–7 CYP2C19 extensive metabolizers (2C19*1/2C19*1) and 7 poor metabolizers (2C19*2/2C19*2)–were selected to participate in this study. Pharmacokinetics of oral voriconazole 200 mg after administration of Ginkgo biloba 120 mg twice daily for 12 days were determined for up to 24 hours by liquid chromatography–electrospray tandem mass spectrometry in a 2-phase randomized crossover study with 4-week washout between phases. Results: For extensive metabolizers, the median value for voriconazole area under the plasma concentration–time curve from zero to infinity (AUC0-00) was 5.17 μg•h/mL after administration of voriconazole alone and 4.28 μg•/mL after voriconazole with Ginkgo biloba (p > 0.05). The other pharmacokinetic parameters of voriconazole such as AUC0-24, time to reach maximum concentration, half-life, and apparent clearance also did not change significantly for extensive metabolizers in the presence of Ginkgo biloba. Pharmacokinetic parameters followed a similar pattern for poor metabolizers. Conclusions: The results suggest that 12 days of treatment with Ginkgo biloba did not significantly alter the single-dose pharmacokinetics of voriconazole in either CYP2C19 extensive or poor metabolizers. Therefore, the pharmacokinetic interactions between voriconazole and Ginkgo biloba may have limited clinical significance.

scholarly journals Safety, toleration, and pharmacokinetics of intravenous azithromycin.

1996 ◽  
Vol 40 (11) ◽  
pp. 2577-2581 ◽  
Author(s):  
D R Luke ◽  
G Foulds ◽  
S F Cohen ◽  
B Levy
Keyword(s):  
Half Life ◽  
Active Drug ◽  
Slow Release ◽  
Volume Of Distribution ◽  
Pharmacokinetic Parameters ◽  
Time Curve ◽  
Concentration Time ◽  
Elimination Half ◽  
The Mean ◽  
Male Subjects

To date, the clinical pharmacology of large intravenous doses of azithromycin has not been described. In the present study, single 2-h intravenous infusions of 1, 2, and 4 g of azithromycin were administered to three parallel groups (in each group, six received active drug and two received placebo) of healthy male subjects. Toleration (assessed by scores of subject-administered visual analog scale tests spanning 0 [good] to 10 [poor]), safety, pharmacokinetics, and serum motilin levels were monitored for up to 240 h after the start of each intravenous infusion. Mean nausea scores of 0.0, 0.0, 1.0, and 0.5 and abdominal cramping scores of 0.0, 0.0, 0.4, and 0.4 for 12-h periods after doses of 0, 1, 2, and 4 g of azithromycin, respectively, suggested that azithromycin was well tolerated. Because of the standardized 1-mg/ml infusates, all subjects in the 4-g dosing group complained of an urgent need to urinate. There were no consistent trends in endogenous motilin levels throughout the study. The maximum concentration of azithromycin in serum (10 micrograms/ml after a 4-g dose) and the area under the concentration-time curve (82 micrograms.h/ml after a 4-g dose) were dose related. The mean pharmacokinetic parameters were an elimination half-life of 69 h, total systemic clearance of 10 ml/min/kg, and a volume of distribution at steady state of 33.3 liters/kg. The pharmacokinetic results suggest that the long half-life of azithromycin is due to extensive uptake and slow release of the drug from tissues rather than an inability to clear the drug. Single intravenous doses of up to 4 g of azithromycin in healthy subjects are generally well tolerated, and quantifiable concentrations may persist in serum for 10 days or more.

scholarly journals Pharmacokinetic Profile of μSMIN Plus™, a new Micronized Diosmin Formulation, after Oral Administration in Rats

2015 ◽  
Vol 10 (9) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Rosario Russo ◽  
Angelo Mancinelli ◽  
Michele Ciccone ◽  
Fabio Terruzzi ◽  
Claudio Pisano ◽  
...  
Keyword(s):  
Oral Administration ◽  
Plasma Concentrations ◽  
Compartmental Analysis ◽  
Pharmacokinetic Profile ◽  
Pharmacokinetic Parameters ◽  
Maximum Plasma ◽  
Sprague Dawley ◽  
Time Curve ◽  
Maximum Plasma Drug Concentration

Diosmin is a naturally occurring flavonoid present in citrus fruits and other plants belonging to the Rutaceae family. It is used for the treatment of chronic venous insufficiency (CVI) for its pheblotonic and vaso-active properties, safety and tolerability as well. The aim of the current in vivo study was to investigate the pharmacokinetic profile of a branded micronized diosmin (μSMIN Plus™) compared with plain micronized diosmin in male Sprague-Dawley rats. After oral administration by gastric gavage, blood samples were collected via jugular vein catheters at regular time intervals from baseline up to 24 hours. Plasma concentrations were assessed by LC/MS. For each animal, the following pharmacokinetic parameters were calculated using a non-compartmental analysis: maximum plasma drug concentration (Cmax), time to reach Cmax (Tmax), area under the plasma concentration-time curve (AUC0-last), elimination half-life (t1/2), and relative oral bioavailability (%F). The results of the current study clearly showed an improvement in the pharmacokinetic parameters in animals treated with μSMIN Plus™ compared with animals treated with micronized diosmin. In particular, μSMIN Plus™ showed a 4-fold increased bioavailability compared with micronized diosmin. In conclusion, the results from the current study provided a preliminary pharmacokinetic profile for μSMIN Plus™, which may represent a new tool for CVI management.

scholarly journals Lack of Effect of Zafirlukast on the Pharmacokinetics of Azithromycin, Clarithromycin, and 14-Hydroxyclarithromycin in Healthy Volunteers

1999 ◽  
Vol 43 (5) ◽  
pp. 1152-1155 ◽  
Author(s):  
Kevin W. Garey ◽  
Charles A. Peloquin ◽  
Paul G. Godo ◽  
Anne N. Nafziger ◽  
Guy W. Amsden
Keyword(s):  
Steady State ◽  
Healthy Subjects ◽  
High Performance ◽  
Pharmacokinetic Parameters ◽  
Steady State Concentration ◽  
Open Label ◽  
Time Curve ◽  
Data Analyses ◽  
Concentration Time ◽  
State Concentration

ABSTRACT This randomized, open-label, crossover study was conducted to investigate whether the coadministration of zafirlukast would affect the pharmacokinetics of azithromycin, clarithromycin, or 14-hydroxyclarithromycin (14-OHC). Twelve healthy subjects (six males and six females) received single 500-mg doses of azithromycin and clarithromycin with and without zafirlukast given to a steady-state concentration. Blood was collected prior to all macrolide doses and for 3 and 10 days after each clarithromycin and azithromycin dose, respectively. Serum was assayed for azithromycin, clarithromycin, and 14-OHC concentrations by validated high-performance liquid chromatography assay systems. Data analyses were done by noncompartmental and nonparametric methods. Analysis of the patients indicated that the addition of steady-state concentrations of zafirlukast did not significantly alter the pharmacokinetic parameters of or overall exposure (based on the area under the concentration-time curve) to azithromycin, clarithromycin, and 14-OHC. While zafirlukast is a known inhibitor of CYP3A4, it does not appear to exert a clinically or statistically significant pharmacokinetic effect on azithromycin, clarithromycin, or 14-OHC.

scholarly journals Association between the Pharmacokinetics and In Vivo Therapeutic Efficacy of Sulfadoxine-Pyrimethamine in Malawian Children

2005 ◽  
Vol 49 (9) ◽  
pp. 3601-3606 ◽  
Author(s):  
Fraction K. Dzinjalamala ◽  
Allan Macheso ◽  
James G. Kublin ◽  
Terrie E. Taylor ◽  
Karen I. Barnes ◽  
...  
Keyword(s):  
Terminal Phase ◽  
Time Curve ◽  
Mean Values ◽  
Concentration Time ◽  
Elimination Half ◽  
Resistant Genotypes ◽  
Parasitological Response ◽  
Phase Elimination ◽  
Malaria Risk Factors

ABSTRACT Sulfadoxine-pyrimethamine (SP) has been widely used in recent years to treat acute uncomplicated Plasmodium falciparum malaria. Risk factors for SP therapeutic failure include young age, subtherapeutic SP concentrations, and resistance-conferring genetic mutations in parasite target enzymes. A substantial proportion of patients are able to clear genetically highly resistant P. falciparum genotypes. To determine whether blood SP concentrations independently affect the patient's ability to clear resistant genotypes, we compared SP pharmacokinetics of cases of adequate clinical and parasitological response (ACPR) with cases of treatment failure (TF). When patients with ACPR and TF were compared, mean values were similar for the day 3 blood pyrimethamine (205 ng/ml versus 172 ng/ml; P = 0.25) and estimated maximum sulfadoxine (79 ± 6.52 versus 69 ± 6.27 μg/ml; P = 0.60) concentrations, for sulfadoxine terminal-phase elimination half-lives (7.15 versus 6.41 days; P = 0.42), and for the extents of sulfadoxine absorption (areas under the concentration-time curve of 932 ± 100 versus 888 ± 78.9 μg day ml−1; P = 0.72). Among patients infected with the quintuple resistant parasites, day 3 blood pyrimethamine concentrations were higher in those who cleared the infection than in those who did not (305 ± 35.4 versus 228 ± 21.7 ng/ml; P = 0.037). Within this subgroup, this finding remained significant after adjusting for endogenous folate levels, age, site, and resistance-conferring mutations (odds ratio: 1.011 [1.003 to 1.024]; P = 0.018). However, as a subgroup analysis, our biologically plausible observation that higher blood pyrimethamine concentrations enhance the ability of patients to clear resistant P. falciparum should be interpreted with caution and needs further validation.

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