scholarly journals Pharmacokinetic Alteration of Baclofen by Multiple Oral Administration of Herbal Medicines in Rats

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Tae Hwan Kim ◽  
Gi-Young Park ◽  
Soyoung Shin ◽  
Dong Rak Kwon ◽  
Won Sik Seo ◽  
...  

The potential pharmacokinetic (PK) interaction of conventional western drug, baclofen, and oriental medications Oyaksungisan (OY) andAchyranthes bidentata radix(AB) extract for the treatment of spasticity has been evaluated. Rats were pretreated with distilled water (DW), OY, or AB extract by oral administration every day for 7 days. After 10 min of the final dose of DW or each herbal medication, baclofen (1 mg/kg) was given by oral administration and plasma concentrations of baclofen were determined by LC/MS/MS. The plasma baclofen concentration-time profiles were then analyzed by noncompartmental analysis and a population PK model was developed. Baclofen was rapidly absorbed, showed biexponential decline with elimination half-life of 3.42–4.10 hr, and mostly excreted into urine. The PK of baclofen was not affected by AB extract pretreatment. However, significantly lower maximum plasma concentration (Cmax) and longer time to reachCmax(Tmax) were observed in OY pretreated rats without changes in the area under the curve (AUC) and the fraction excreted into urine (Furine). The absorption rate (Ka) of baclofen was significantly decreased in OY pretreated rats. These data suggested that repeated doses of OY might delay the absorption of baclofen without changes in extent of absorption, which needs further evaluation for clinical significance.

2019 ◽  
Vol 19 (1) ◽  
pp. 31-45
Author(s):  
Meena K. Yadav ◽  
Laxmi Tripathi

Background: N-{[3-(4-chlorophenyl)-4-oxo-3, 4-dihydroquinazolin-2-yl] methyl}, 2-[(2- isopropyl-5-methyl) 1-cyclohexylidene] hydrazinecarboxamide QS11 was designed by computational study. It possessed essential pharmacophoric features for anticonvulsant activity and showed good docking with iGluRs (Kainate) glutamate receptor. Methods: QSAR and ADMET screening results suggested that QS11 would possess good potency for anticonvulsant activity. QS11 was synthesised and evaluated for its anticonvulsant activity and neurotoxicity. QS11 showed protection in strychnine, thiosemicarbazide, 4-aminopyridine and scPTZ induced seizure models and MES seizure model. QS11 showed higher ED50, TD50 and PI values as compared to the standard drugs in both MES and scPTZ screen. A high safety profile (HD50/ED50 values) was noted and hypnosis, analgesia, and anaesthesia were only observed at higher doses. No considerable increase or decrease in the concentration of liver enzymes was observed. Optimized QS11 was subjected to preclinical (in-vivo) studies and the pharmacokinetic performance of the sample was investigated. The result revealed that the pharmacokinetic performance of QS11 achieved maximum plasma concentrations (Cmax) of 0.315 ± 0.011 µg/mL at Tmax of 2.0 ± 0.13 h, area under the curve (AUC0-∞) value 4.591 ± 0.163 µg/ml x h, elimination half-life (T1/2) 6.28 ± 0.71 h and elimination rate constant was found 0.110 ± 0.013 h-1. Results and Conclusion: Above evidences indicate that QS11 could serve as a lead for development of new antiepileptic drugs.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 778
Author(s):  
Bettina Gerner ◽  
Oliver Scherf-Clavel

Cabozantinib (CAB) is a receptor tyrosine kinase inhibitor approved for the treatment of several cancer types. Enterohepatic recirculation (EHC) of the substance is assumed but has not been further investigated yet. CAB is mainly metabolized via CYP3A4 and is susceptible for drug–drug interactions (DDI). The goal of this work was to develop a physiologically based pharmacokinetic (PBPK) model to investigate EHC, to simulate DDI with Rifampin and to simulate subjects with hepatic impairment. The model was established using PK-Sim® and six human clinical studies. The inclusion of an EHC process into the model led to the most accurate description of the pharmacokinetic behavior of CAB. The model was able to predict plasma concentrations with low bias and good precision. Ninety-seven percent of all simulated plasma concentrations fell within 2-fold of the corresponding concentration observed. Maximum plasma concentration (Cmax) and area under the curve (AUC) were predicted correctly (predicted/observed ratio of 0.9–1.2 for AUC and 0.8–1.1 for Cmax). DDI with Rifampin led to a reduction in predicted AUC by 77%. Several physiological parameters were adapted to simulate hepatic impairment correctly. This is the first CAB model used to simulate DDI with Rifampin and hepatic impairment including EHC, which can serve as a starting point for further simulations with regard to special populations.


2017 ◽  
Vol 20 (3) ◽  
pp. 535-538
Author(s):  
A. Di Salvo ◽  
M. Giorgi ◽  
H.K. Lee ◽  
C. Vercelli ◽  
F. Rueca ◽  
...  

Abstract Sheep are often subjected to painful procedures and thus they need to be treated with analgesics. Nevertheless, knowledges about pharmacokinetic features of these drugs in this species are poor. The aim of this study was to evaluate plasma behaviour of cimicoxib in sheep after a single oral administration at two different dose rates (4 and 6 mg/kg). Maximum plasma concentrations of cimicoxib were equal to 273.78 (median value; range 189.00-567.32) and 565.01 (range 308.27-822.59) ng/mL after treatment with 4 and 6 mg/kg, respectively. The time of maximum concentration (Tmax) was achieved between 4 and 10 hours following treatment at the lower dose, and between 6 and 10 hours after the administration of the higher dose, with one sheep achieving the concentration peak at 0.75 hours. The slow absorption and the great individual variability in plasma concentration, probably due to ruminal effects, suggest that cimicoxib is not suitable for oral treatment in sheep.


2011 ◽  
Vol 56 (1) ◽  
pp. 70-74 ◽  
Author(s):  
Paul M. Beringer ◽  
Heather Owens ◽  
Albert Nguyen ◽  
Debbie Benitez ◽  
Adupa Rao ◽  
...  

ABSTRACTCystic fibrosis (CF) is characterized by a chronic neutrophilic inflammatory response resulting in airway remodeling and progressive loss of lung function. Doxycycline is a tetracycline antibiotic that inhibits matrix metalloproteinase 9, a protease known to be associated with the severity of lung disease in CF. The pharmacokinetics of doxycycline was investigated during the course of a clinical trial to evaluate the short-term efficacy and safety in adults with CF. Plasma samples were obtained from 14 patients following a single intravenous dose and after 2 and 4 weeks of oral administration of doses ranging from 40 to 200 mg daily. The data were analyzed using noncompartmental and compartmental pharmacokinetics. The maximum concentration of drug in serum (Cmax) and area under the concentration-time curve from 0 h to infinity (AUC0-∞) values ranged from 1.0 to 3.16 mg/liter and 15.2 to 47.8 mg/liter × h, respectively, following single intravenous doses of 40 to 200 mg.Cmaxand time to maximum concentration of drug in serum (Tmax) values following multiple-dose oral administration ranged from 1.15 to 3.04 mg/liter and 1.50 to 2.33 h, respectively, on day 14 and 1.48 to 3.57 mg/liter and 1.00 to 2.17 on day 28. Predose sputum/plasma concentration ratios on days 14 and 28 ranged from 0.33 to 1.1 (mean, 0.71 ± 0.33), indicating moderate pulmonary penetration. A 2-compartment model best described the combined intravenous and oral data. Absorption was slow and delayed (absorption rate constant [Ka], 0.414 h−1; lag time, 0.484 h) but complete (bioavailability [F], 1.16). The distribution and elimination half-lives were 0.557 and 18.1 h, respectively. Based on these data, the plasma concentrations at the highest dose, 200 mg/day, are in the range reported to produce anti-inflammatory effectsin vivoand should be evaluated in clinical trials.


2015 ◽  
Vol 10 (9) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Rosario Russo ◽  
Angelo Mancinelli ◽  
Michele Ciccone ◽  
Fabio Terruzzi ◽  
Claudio Pisano ◽  
...  

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.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 468-468
Author(s):  
Geoffrey Sasaki ◽  
Yael Vodovotz ◽  
Zhongtang Yu ◽  
Richard Bruno

Abstract Objectives Green tea extract (GTE) protects against obesity in rodents by reducing gut permeability that otherwise provokes endotoxemia-mediated inflammation. However, whether obesity affects catechin bioavailability and microbial metabolism is unknown. We hypothesized that obesity will reduce catechin bioavailability by increasing microbial biotransformation of catechins. Methods Obese persons (n = 10 M/7F; 33.5 ± 0.7 kg/m2) and age-matched healthy persons (n = 10 M/9F; 21.7 ± 0.4 kg/m2) completed a pharmacokinetics (PK) trial in which a GTE confection [290 mg epigallocatechin gallate (EGCG), 87 mg epigallocatechin (EGC), 39 mg epicatechin (EC), 28 mg epicatechin gallate (ECG)] was ingested prior to collecting plasma at 0, 0.25, 0.5, 1, 2, 3, 5, 8, 10, and 12 h and urine from 0–4, 4–8, 8–12, and 12–24 h. Stool samples were collected and gut permeability was assessed prior to the 12-h PK trial. Plasma and urinary catechin/catechin-derived microbial metabolites were assessed following enzymatic hydrolysis by LC-MS. Results Regardless of health status, relative bioavailability, based on plasma area under the curve (AUC0–12 h), of GTE catechins were: EGCG > EGC > ECG > EC. However, obese persons had 24–27% lower plasma AUC0–12 h for the four catechins compared to lean persons (P < 0.05). They also had 18–36% lower maximum plasma concentrations (Cmax) of GTE catechins but 12 h plasma catechin concentrations were unaffected by obesity status (P > 0.05). 3ʹ,4ʹ-γ-valerolactone (3,4-VL) was detected in the plasma of all participants, while 3ʹ,4ʹ,5ʹ-γ-valerolactone (3,4,5-VL) was detected in 74% and 82% of lean and obese persons, respectively. Plasma AUC0–12 h for these VL metabolites did not differ by obesity status. EGC, EC, 3,4-VL, and 3,4,5-VL, but not EGCG and ECG, were primarily present in urine and urinary total VLs were increased compared with total urinary catechins. However, 24-h urinary excretion of catechins and VLs were unaffected by obesity. Conclusions Obesity reduces GTE catechin bioavailability and Cmax independent of any change in VL metabolite appearance or urinary elimination of catechins, suggesting a gut-level mechanism that limits catechin absorption. Funding Sources Supported by USDA-NIFA and the Foods for Health Discovery Theme at The Ohio State University.


1993 ◽  
Vol 4 (3) ◽  
pp. 155-159 ◽  
Author(s):  
M. Qian ◽  
A. R. Swagler ◽  
M. Mehta ◽  
C.T. Vishwanathan ◽  
J. M. Gallo

The current investigation was conducted to determine if zidovudine (AZT) altered the pharmacokinetics of dideoxyinosine (ddl) in non-hurnan primates, an appropriate animal model for AZT and ddl pharmacokinetics in human. Each of nine animals received 20 mg kg−1 of ddl intravenously in the absence and presence of two different dosage regimens of AZT. For each combination regimen, AZT was administered as a combined i.v. bolus-constant rate infusion regimen for 30 min that produced AZT plasma concentrations of about 4 μg ml−1 in six animals (low dose group) and 11 μg ml−1 in three others (high dose group). Serial blood samples were collected, and pharmacokinetic parameters for ddl were calculated based on plasma ddl concentrations measured by HPLC techniques. The pharmacokinetics of ddl given alone in the first phase of the low ( n = 6) and high ( n = 6) dose AZT groups, resulted in a mean elimination half-life 1.54 and 1.9h, a mean total clearance of 0.62 and 0.731 h−1 kg−1, and a mean steady state volume of distribution of 1.02 and 0.891 kg−1, respectively. Following combined ddl and AZT administrations, in both the low and high dose AZT groups, plasma concentration-time profiles of ddl were similar for each monkey, and no statistical differences were observed in the pharmacokinetic parameters compared to those obtained when ddl was given alone. The fact that AZT does not alter the pharmacokinetics of ddl at the range of AZT dose studied provides a basis for rational dosage design for combined ddl and AZT treatments in HIV infection.


Blood ◽  
1998 ◽  
Vol 91 (5) ◽  
pp. 1533-1541 ◽  
Author(s):  
Gladys I. Rodriguez ◽  
John G. Kuhn ◽  
Geoffrey R. Weiss ◽  
Susan G. Hilsenbeck ◽  
John R. Eckardt ◽  
...  

Abstract Despite the widespread usage of hydroxyurea in the treatment of both malignant and nonmalignant diseases and a recent expansion in the recognition of its potential therapeutic applications, there have been few detailed studies of hydroxyurea's pharmacokinetic (PK) behavior and oral bioavailability. Parenteral administration schedules have been evaluated because of concerns about the possibility for significant interindividual variability in the PK behavior and bioavailability of hydroxyurea after oral administration. In this PK and bioavailability study, 29 patients with advanced solid malignancies were randomized to treatment with 2,000 mg hydroxyurea administered either orally or as a 30-minute intravenous (IV) infusion accompanied by extensive plasma and urine sampling for PK studies. After 3 weeks of treatment with hydroxyurea (80 mg/kg orally every 3 days followed by a 1-week washout period), patients were crossed over to the alternate route of administration, at which time extensive PK studies were repeated. Three days later, patients continued treatment with 80 mg/kg hydroxyurea orally every 3 days for 3 weeks, followed by a 1-week rest period. Thereafter, 80 mg/kg hydroxyurea was administered orally every 3 days. Twenty-two of 29 patients had extensive plasma and urine sampling performed after treatment with both oral and IV hydroxyurea. Oral bioavailability (F) averaged 108%. Moreover, interindividual variability in F was low, as indicated by 19 of 22 individual F values within a narrow range of 85% to 127% and a modest coefficient of variation of 17%. The time in which maximum plasma concentrations (Cmax) were achieved averaged 1.22 hours with an average lag time of 0.22 hours after oral administration. Except for Cmax, which was 19.5% higher after IV drug administration, the PK profiles of oral and IV hydroxyurea were very similar. The plasma disposition of hydroxyurea was well described by a linear two-compartment model. The initial harmonic mean half-lives for oral and IV hydroxyurea were 1.78 and 0.63 hours, respectively, and the harmonic mean terminal half-lives were 3.32 and 3.39 hours, respectively. For IV hydroxyurea, systemic clearance averaged 76.16 mL/min/m2 and the mean volume of distribution at steady-state was 19.71 L/m2, whereas Cloral/F and Voral/F averaged 73.16 mL/min/m2 and 19.65 L/m2, respectively, after oral administration. The percentage of the administered dose of hydroxyurea that was excreted unchanged into the urine was nearly identical after oral and IV administration—36.84% and 35.82%, respectively. Additionally, the acute toxic effects of hydroxyurea after treatment on both routes were similar. Relationships between pertinent PK parameters and the principal toxicity, neutropenia, were sought, but no pharmacodynamic relationships were evident. From PK, bioavailability, and toxicologic standpoints, these results indicate that there are no clear advantages for administering hydroxyurea by the IV route except in situations when oral administration is not possible and/or in the case of severe gastrointestinal impairment.


2018 ◽  
Vol 62 (8) ◽  
Author(s):  
Wendy Ankrom ◽  
Ka Lai Yee ◽  
Rosa I. Sanchez ◽  
Adedayo Adedoyin ◽  
Li Fan ◽  
...  

ABSTRACT Doravirine is a novel nonnucleoside reverse transcriptase inhibitor in development for use with other antiretroviral therapies to treat human immunodeficiency virus type 1 (HIV-1) infection. Doravirine metabolism predominantly occurs via cytochrome P450 3A with <10% of elimination occurring via the renal pathway. As severe renal impairment can alter the pharmacokinetics (PK) of metabolically eliminated drugs, the effect of severe renal impairment on doravirine PK was assessed. A single dose of doravirine 100 mg was administered to subjects aged 18 to 75 years with an estimated glomerular filtration rate (eGFR) of <30 ml/min/1.73 m2 (severe renal impairment group) and healthy controls with an eGFR of ≥80 ml/min/1.73 m2, matched to the mean of the renal impairment group by age (±10 years) and weight (±10 kg). Doravirine plasma concentrations were determined at regular intervals, and safety was monitored throughout. The geometric mean ratios (90% confidence interval) for severe renal impairment/healthy subjects were 1.43 (1.00, 2.04), 1.38 (0.99, 1.92), and 0.83 (0.61, 1.15) for the plasma doravirine area under the curve from zero to infinity (AUC0–∞), plasma concentration at 24 h postdose (C24), and maximum plasma concentration (Cmax), respectively. Doravirine was generally well tolerated in both groups. Based on the overall efficacy, safety, and PK profile of doravirine, the minor effect of severe renal impairment on doravirine PK observed in this study is not considered clinically meaningful. (This study has been registered at ClinicalTrials.gov under identifier NCT02641067.)


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 7077-7077
Author(s):  
Jennifer Ann Woyach ◽  
Joseph M. Flynn ◽  
Jeffrey Alan Jones ◽  
Leslie A. Andritsos ◽  
Margaret Lucas ◽  
...  

7077 Background: CLL is an incurable malignancy, and survival for patients (pts) with relapsed disease is limited. Carfilzomib (CFZ) has shown efficacy in multiple myeloma, and our group has shown significant in vitro activity in primary CLL cells. Therefore, we have undertaken a phase I trial of this agent in CLL. Methods: This is a single institution phase I trial of CFZ in pts with relapsed or refractory CLL. Primary endpoints were to determine maximal tolerated dose (MTD) and describe toxicity. Pts with CLL relapsed after at least one therapy were enrolled using a 3x3 design. CFZ was administered on the standard myeloma schedule. The first two doses were administered at 20 mg/m2 with remainder given at doses starting at 27 mg/m2 for dose level 1 with escalation to 56 mg/m2. Results: 17 pts received at least 1 dose of CFZ. 12 pts completed at least 1 cycle of therapy, with the remaining 5 experiencing PD during cycle 1. The MTD was not reached, with 3 pts accrued to each dose level to the maximal dose tested without dose limiting toxicity. Most adverse events (AE) were grade (G) 1 or 2. G3/4 AE were quickly reversible and included G3 neutropenia (4 pts), G4 neutropenia (2), G3 febrile neutropenia (1), and G3 thrombocytopenia (3). G1/2 toxicities observed in ≥ 20% of pts included anemia (10), thrombocytopenia (7), and hypocalcemia (8). Median number of cycles was 3, with 9 pts achieving stable disease after 2 cycles. Of 3 pts enrolled at maximal dose level, 2 remain on therapy after 5 and 7 months, with 1 achieving a clinical partial response. Of 5 evaluable pts, at least 50% proteasome inhibition was seen in all at 1 hour, with minimal recovery at 24 hours. PK was best characterized by a two-compartment model. Maximum plasma concentrations across all dose levels ranged from 0.81 to 8.1 uM. Across the evaluated dose range, area under the curve increased in an apparent dose-proportional manner. Conclusions: Despite relatively limited efficacy in this study, CFZ has acceptable toxicity in CLL, with no MTD identified up to 56 mg/m2. This suggests that CFZ may be better studied in CLL using a different schedule or in combination with other active agents. Clinical trial information: NCT01212380.


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