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1.
Ohno T Nakade S Nakayama K Kitagawa J Ueda S Miyabe H Masuda Y Miyata Y 《British journal of clinical pharmacology》2008,65(2):197-202
Aims
To investigate the absolute bioavailability of imidafenacin, a new muscarinic receptor antagonist, a single oral dose of 0.1 mg imidafenacin was compared with an intravenous (i.v.) infusion dose of 0.028 mg of the drug in healthy subjects.Methods
Fourteen healthy male subjects, aged 21–45 years, received a single oral dose of 0.1 mg imidafenacin or an i.v. infusion dose of 0.028 mg imidafenacin over 15 min at two treatment sessions separated by a 1-week wash-out period. Plasma concentrations of imidafenacin and the major metabolites M-2 and imidafenacin-N-glucuronide (N-Glu) were determined. The urinary excretion of imidafenacin was also evaluated. Analytes in biological samples were measured by liquid chromatography tandem mass spectrometry.Results
The absolute oral bioavailability of imidafenacin was 57.8% (95% confidence interval 54.1, 61.4) with a total clearance of 29.5 ± 6.3 l h−1. The steady-state volume of distribution was 122 ± 28 l, suggesting that imidafenacin distributes to tissues. Renal clearance after i.v. infusion was 3.44 ± 1.08 l h−1, demonstrating that renal clearance plays only a minor role in the elimination of imidafenacin. The ratio of AUCt of both M-2 and N-Glu to that of imidafenacin was reduced after i.v. infusion from that seen after oral administration, suggesting that M-2 and N-Glu in plasma after oral administration were generated primarily due to first-pass metabolism. No serious adverse events were reported during the study.Conclusions
The absolute mean oral bioavailability of imidafenacin was determined to be 57.8%. Imidafenacin was well tolerated following both oral administration and i.v. infusion.What is already known about this subject
- The absolute bioavailability of imidafenacin in rats and dogs is 5.6% and 36.1%, respectively.
- The pharmacokinetic profiles of imidafenacin after oral administration have been revealed.
- Imidafenacin is primarily metabolized to metabolites by CYP3A4 and UGT1A4.
What this study adds
- The absolute bioavailability of imidafenacin in human is 57.8%.
- The pharmacokinetic profiles of imidafenacin after intravenous administration are revealed.
- The formation of metabolites in the plasma is caused mainly by first-pass effects.
2.
David W. Boulton Sreeneeranj Kasichayanula Chi Fung Keung Mark E. Arnold Lisa J. Christopher Xiaohui Xu Frank LaCreta 《British journal of clinical pharmacology》2013,75(3):763-768
Aim
To determine the absolute oral bioavailability (Fp.o.) of saxagliptin and dapagliflozin using simultaneous intravenous 14C‐microdose/therapeutic oral dosing (i.v.micro + oraltherap).Methods
The Fp.o. values of saxagliptin and dapagliflozin were determined in healthy subjects (n = 7 and 8, respectively) following the concomitant administration of single i.v. micro doses with unlabelled oraltherap doses. Accelerator mass spectrometry and liquid chromatography‐tandem mass spectrometry were used to quantify the labelled and unlabelled drug, respectively.Results
The geometric mean point estimates (90% confidence interval) Fp.o. values for saxagliptin and dapagliflozin were 50% (48, 53%) and 78% (73, 83%), respectively. The i.v.micro had similar pharmacokinetics to oraltherap.Conclusions
Simultaneous i.v.micro + oraltherap dosing is a valuable tool to assess human absolute bioavailability. 相似文献3.
Adam Frymoyer Davide Verotta Pamala Jacobson Janel Long-Boyle 《British journal of clinical pharmacology》2013,75(2):463-475
Aim
To evaluate pharmacogenetic factors as contributors to the variability of unbound mycophenolic acid (MPA) exposure in adult allogeneic haematopoietic cell transplantation (alloHCT) recipients.Methods
A population-based pharmacokinetic (PK) model of unbound MPA was developed using non-linear mixed-effects modelling (nonmem). Previously collected intensive unbound MPA PK data from 132 adult alloHCT recipients after oral and intravenous dosing of the prodrug mycophenolate mofetil (MMF) were used. In addition to clinical covariates, genetic polymorphisms in UGT1A8, UGT1A9, UGT2B7 and MRP2 were evaluated for their impact on unbound MPA PK.Results
Unbound MPA concentration−time data were well described by a two compartment model with first order absorption and linear elimination. For the typical patient (52 years of age, creatinine clearance 86 ml min−1), the median estimated values [coefficient of variation, %, (CV)] of systemic clearance, intercompartmental clearance, central and peripheral volumes of MPA were 1610 l h−1 (37.4%), 541 l h−1 (75.6%), 1230 l (37.5%), and 6140 l (120%), respectively. After oral dosing, bioavailability was low (0.56) and highly variable (CV 46%). No genetic polymorphisms tested significantly explained the variability among individuals. Creatinine clearance was a small but significant predictor of unbound MPA CL. No other clinical covariates impacted unbound MPA PK.Conclusions
In adult alloHCT recipients, variability in unbound MPA AUC was large and remained largely unexplained even with the inclusion of pharmacogenetic information. Targeting unbound MPA AUC in a patient will require therapeutic drug monitoring. 相似文献4.
Ajay Madan Zhihong O'Brien Jianyun Wen Chris O'Brien Robert H. Farber Graham Beaton Paul Crowe Berend Oosterhuis R. Colin Garner Graham Lappin & Haig P. Bozigian 《British journal of clinical pharmacology》2009,67(3):288-298
AIMS
To evaluate the pharmacokinetics (PK) of five H1 receptor antagonists in human volunteers after a single oral and intravenous (i.v.) microdose (0.1 mg).METHODS
Five H1 receptor antagonists, namely NBI-1, NBI-2, NBI-3, NBI-4 and diphenhydramine, were administered to human volunteers as a single 0.1-mg oral and i.v. dose. Blood samples were collected up to 48 h, and the parent compound in the plasma extract was quantified by high-performance liquid chromatography and accelerator mass spectroscopy.RESULTS
The median clearance (CL), apparent volume of distribution (Vd) and apparent terminal elimination half-life (t1/2) of diphenhydramine after an i.v. microdose were 24.7 l h−1, 302 l and 9.3 h, and the oral Cmax and AUC0–∞ were 0.195 ng ml−1 and 1.52 ng h ml−1, respectively. These data were consistent with previously published diphenhydramine data at 500 times the microdose. The rank order of oral bioavailability of the five compounds was as follows: NBI-2 > NBI-1 > NBI-3 > diphenhydramine > NBI-4, whereas the rank order for CL was NBI-4 > diphenhydramine > NBI-1 > NBI-3 > NBI-2.CONCLUSIONS
Human microdosing provided estimates of clinical PK of four structurally related compounds, which were deemed useful for compound selection. 相似文献5.
Thor Ostenfeld Claire Beaumont Jonathan Bullman Maria Beaumont Phillip Jeffrey 《British journal of clinical pharmacology》2012,74(6):1033-1044
AIM
The primary objective was to evaluate the pharmacokinetics (PK) of the novel EP1 antagonist GSK269984A in human volunteers after a single oral and intravenous (i.v.) microdose (100 µg).METHOD
GSK269984A was administered to two groups of healthy human volunteers as a single oral (n= 5) or i.v. (n= 5) microdose (100 µg). Blood samples were collected for up to 24 h and the parent drug concentrations were measured in separated plasma using a validated high pressure liquid chromatography-tandem mass spectrometry method following solid phase extraction.RESULTS
Following the i.v. microdose, the geometric mean values for clearance (CL), steady-state volume of distribution (Vss) and terminal elimination half-life (t1/2) of GSK269984A were 9.8 l h−1, 62.8 l and 8.2 h. Cmax and AUC(0,∞) were 3.2 ng ml−1 and 10.2 ng ml−1 h, respectively; the corresponding oral parameters were 1.8 ng ml−1 and 9.8 ng ml−1 h, respectively. Absolute oral bioavailability was estimated to be 95%. These data were inconsistent with predictions of human PK based on allometric scaling of in vivo PK data from three pre-clinical species (rat, dog and monkey).CONCLUSION
For drug development programmes characterized by inconsistencies between pre-clinical in vitro metabolic and in vivo PK data, and where uncertainty exists with respect to allometric predictions of the human PK profile, these data support the early application of a human microdose study to facilitate the selection of compounds for further clinical development. 相似文献6.
Aida Kulo Mariska Y. Peeters Karel Allegaert Anne Smits Jan de Hoon Rene Verbesselt Liesbeth Lewi Marc van de Velde Catherijne A. J. Knibbe 《British journal of clinical pharmacology》2013,75(3):850-860
Aim
A recent report on intravenous (i.v.) paracetamol pharmacokinetics (PK) showed a higher total clearance in women at delivery compared with non‐pregnant women. To describe the paracetamol metabolic and elimination routes involved in this increase in clearance, we performed a population PK analysis in women at delivery and post‐partum in which the different pathways were considered.Methods
Population PK parameters using non‐linear mixed effect modelling were estimated in a two‐period PK study in women to whom i.v. paracetamol (2 g loading dose followed by 1 g every 6 h up to 24 h) was administered immediately following Caesarean delivery and in a subgroup of the same women to whom single 2 g i.v.loading dose was administered 10–15 weeks post‐partum.Results
Population PK analysis was performed based on 255 plasma and 71 urine samples collected in 39 women at delivery and in eight of these 39 women 12 weeks post‐partum. Total clearance was higher in women at delivery compared with 12th post‐partum week (21.1 vs. 11.7 l h−1) due to higher clearances to paracetamol glucuronide (11.6 vs. 4.76 l h−1), to oxidative metabolites (4.95 vs. 2.77 l h−1) and of unchanged paracetamol (1.15 vs. 0.75 l h−1). In contrast, there was no difference in clearance to paracetamol sulphate.Conclusion
The increased total paracetamol clearance at delivery is caused by a disproportional increase in glucuronidation clearance and a proportional increase in clearance of unchanged paracetamol and in oxidation clearance, of which the latter may potentially limit further dose increase in this patient group. 相似文献7.
Xu Z Bouman-Thio E Comisar C Frederick B Van Hartingsveldt B Marini JC Davis HM Zhou H 《British journal of clinical pharmacology》2011,72(2):270-281
AIMS
To assess the safety, tolerability, pharmacokinetics (PK) and immunogenicity of sirukumab (CNTO 136) following intravenous (i.v.) infusion in healthy subjects.METHODS
Forty-five healthy adult subjects (38 men and seven women) were randomly assigned to receive a single i.v. dose of placebo or sirukumab (0.3, 1, 3, 6 or 10 mg kg−1 in a dose-escalating manner). All treated subjects were observed for 96 h post infusion and underwent 20-week follow-up evaluations. Serum samples were collected to measure sirukumab concentrations, pharmacodynamic biomarkers and antibodies to sirukumab. Non-compartmental analysis and population PK modelling were conducted to characterize the PK of sirukumab.RESULTS
Adverse events were generally brief in duration, mild or moderate in intensity and non-dose-dependent. No serious adverse events were observed in the sirukumab-treated subjects. Both Cmax and AUC(0,∞) increased in an approximately dose-proportional manner. Median terminal half-life ranged from 18.5 to 29.6 days. A two-compartment model adequately described the PK of sirukumab following i.v. administration. Population estimates for the clearance (CL), the central volume of distribution (V1), the inter-compartmental clearance (Q) and the peripheral volume of distribution (V2) were 0.364 l day−1, 3.28 l, 0.588 l day−1 and 4.97 l, respectively. Compared with placebo subjects, a sustained decrease from baseline in C-reactive protein was observed in all sirukumab-treated dose groups, although no clear dose–response relationship was observed. No subjects were positive for antibodies to sirukumab.CONCLUSIONS
Sirukumab had a well-tolerated safety profile, desirable PK characteristics and a low incidence of immunogenicity following an i.v. infusion of 0.3 to 10 mg kg−1 in healthy subjects. 相似文献8.
K K?ck W J Pan J M Gow M J Horner J P Gibbs A Colbert T J Goletz K J Newhall W A Rees Y Sun Y Zhang J C O'Neill A N Umble-Romero S P Prokop C D Krill L Som S A Buntich M W Trimble W H Tsuji J E Towne 《British journal of pharmacology》2015,172(1):159-172
BACKGROUND AND PURPOSE
AMG 139 is a human anti-IL-23 antibody currently in a phase II trial for treating Crohn''s disease. To support its clinical development in humans, in vitro assays and in vivo studies were conducted in cynomolgus monkeys to determine the pharmacology, preclinical characteristics and safety of this monoclonal antibody.EXPERIMENTAL APPROACH
The in vitro pharmacology, pharmacokinetics (PK), pharmacodynamics and toxicology of AMG 139, after single or weekly i.v. or s.c. administration for up to 26 weeks, were evaluated in cynomolgus monkeys.KEY RESULTS
AMG 139 bound with high affinity to both human and cynomolgus monkey IL-23 and specifically neutralized the biological activity of IL-23 without binding or blocking IL-12. After a single dose, linear PK with s.c. bioavailability of 81% and mean half-life of 8.4–13 days were observed. After weekly s.c. dosing for 3 or 6 months, AMG 139 exposure increased approximately dose-proportionally from 30 to 300 mg·kg−1 and mean accumulation between the first and last dose ranged from 2- to 3.5-fold. Peripheral blood immunophenotyping, T-cell-dependent antigen responses and bone formation markers were not different between AMG 139 and vehicle treatment. No adverse clinical signs, effects on body weight, vital signs, ophthalmic parameters, clinical pathology, ECG, organ weights or histopathology were observed in the monkeys with the highest dose of AMG 139 tested (300 mg·kg−1 s.c. or i.v.).CONCLUSIONS AND IMPLICATIONS
The in vitro pharmacology, PK, immunogenicity and safety characteristics of AMG 139 in cynomolgus monkeys support its continued clinical development for the treatment of various inflammatory diseases. 相似文献9.
Kyoung Soo Lim Joo-Youn Cho Bo-Hyung Kim Jung-Ryul Kim Hwa-Sook Kim Dong-Kyu Kim Sung-Ho Kim Hyeon Joo Yim Sung-Hack Lee Sang-Goo Shin In-Jin Jang Kyung-Sang Yu 《British journal of clinical pharmacology》2009,68(6):883-890
AIMS
LC15-0444 is a selective and competitive inhibitor of dipeptidyl peptidase (DPP) IV with potential for the treatment of Type 2 diabetes. The aim was to investigate the pharmacokinetic (PK) and pharmacodynamic (PD) profiles after multiple oral ascending doses of LC15-0444 in healthy male subjects.METHODS
A dose block-randomized, double-blind, placebo-controlled, parallel group study was performed in three groups with 10 subjects (eight for active drug; two for placebo) per group; each group received 200, 400 or 600 mg of LC15-0444 once daily for 10 days. Blood and urine samples were collected up to 24 h after the first dosing and up to 72 h after the last dosing.RESULTS
The LC15-0444 concentration–time profiles exhibited characteristics of multicompartment disposition. No dose- or time-dependent change in PK parameters was observed. Mean elimination half-life was in a range 16.6–20.1 h in the dose groups. Mean renal clearance and fraction of unchanged drug excreted in urine was 18.6–21.9 and 0.40–0.48 l h−1, respectively. In the steady state, mean accumulation ratios by dose groups were between 1.22 and 1.31. More than 80% inhibition of DPP IV activity from baseline was sustained for >24 h in all dose groups.CONCLUSIONS
This study provides evidence of the pharmacological activity of LC15-0444 in humans. LC15-0444 possesses PK and PD characteristics that support a once-daily dosing regimen. 相似文献10.
Ina Scholz Heike Oberwittler Klaus-Dieter Riedel Jürgen Burhenne Johanna Weiss Walter E Haefeli Gerd Mikus 《British journal of clinical pharmacology》2009,68(6):906-915
AIMS
The aim was to determine the pharmacokinetics of voriconazole after a single oral dose in comparison with intravenous (i.v.) administration in healthy individuals stratified according to the cytochrome P450 (CYP) 2C19 genotype. In addition, the possible metabolic pathways and their modulation according to CYP2C19 genotype were investigated after oral and i.v. administration of voriconazole.METHODS
In a single-centre, open-label, two-period crossover study 20 participants received single doses of 400 mg voriconazole orally and 400 mg voriconazole intravenously in randomized order. Blood and urine samples were collected up to 96 h post dose and the voriconazole and three major metabolites were quantified by high-performance liquid chromatography coupled to mass spectroscopy.RESULTS
Absolute oral bioavailability of voriconazole was 82.6% (74.1, 91.0). It ranged from 94.4% (78.8, 109.9) in CYP2C19 poor metabolizers to 75.2% (62.9, 87.4) in extensive metabolizers. In contrast to voriconazole and its N-oxide, the plasma concentrations of both hydroxylated metabolites showed a large second peak after 24 h. Independent of the route of administration, voriconazole partial metabolic hydroxylation after i.v. administration was eightfold higher compared with N-oxidation [48.8 ml min−1 (30.5, 67.1) vs. 6.1 ml min−1 (4.1, 8.0)]. The formation of the metabolites was related to CYP2C19 activity.CONCLUSIONS
Independent of the route of administration, voriconazole exposure was three times higher in CYP2C19 poor metabolizers compared with extensive metabolizers. Voriconazole has a high bioavailability with no large differences between the CYP2C19 genotypes. The hydroxylation pathway of voriconazole elimination exceeded the N-oxidation, both influenced by the CYP2C19 genotype. 相似文献11.
April M Barbour Lea Sarov-Blat Gengqian Cai Michael J Fossler Dennis L Sprecher Johann Graggaber Adam T McGeoch Jo Maison Joseph Cheriyan 《British journal of clinical pharmacology》2013,76(1):99-106
Aims
The purpose of this study was to establish safety and tolerability of a single intravenous (IV) infusion of a p38 mitogen-activated protein kinase inhibitor, losmapimod, to obtain therapeutic levels rapidly for a potential acute coronary syndrome indication. Pharmacokinetics (PK) following IV dosing were characterized, and pharmacokinetic/pharmacodynamic (PK/PD) relationships between losmapimod and phosphorylated heat shock protein 27 (pHSP27) and high-sensitivity C-reactive protein were explored.Methods
Healthy volunteers received 1 mg losmapimod IV over 15 min (n = 4) or 3 mg IV over 15 min followed by a washout period and then 15 mg orally (PO; n = 12). Pharmacokinetic parameters were calculated by noncompartmental methods. The PK/PD relationships were explored using modelling and simulation.Results
There were no deaths, nonfatal serious adverse events or adverse events leading to withdrawal. Headache was the only adverse event reported more than once (n = 3 following oral dosing). Following 3 mg IV and 15 mg PO, Cmax was 59.4 and 45.9 μg l−1 and AUC0–∞ was 171.1 and 528.0 μg h l−1, respectively. Absolute oral bioavailability was 0.62 [90% confidence interval (CI) 0.56, 0.68]. Following 3 mg IV and 15 mg PO, maximal reductions in pHSP27 were 44% (95% CI 38%, 50%) and 55% (95% CI 50%, 59%) occurring at 30 min and 4 h, respectively. There was a 17% decrease (95% CI 9%, 24%) in high-sensitivity C-reactive protein 24 h following oral dosing. A direct-link maximal inhibitory effect model related plasma concentrations to pHSP27 concentrations.Conclusions
A single IV infusion of losmapimod in healthy volunteers was safe and well tolerated, and may potentially serve as an initial loading dose in acute coronary syndrome as rapid exposure is achieved. 相似文献12.
Elena Soto Satoshi Shoji Chieko Muto Yoshiro Tomono Scott Marshall 《British journal of clinical pharmacology》2014,77(3):509-521
Aims
The aims of this study were to develop a population pharmacokinetic (PK) model of ampicillin and sulbactam, to identify patient characteristics influencing the PK, and to explore the relationship between dose regimen and degree of renal impairment with exposure and time above minimum inhibitory concentration (MIC).Methods
This analysis was performed on PK data for ampicillin and sulbactam and MIC data from a clinical trial in Japanese patients with community acquired pneumonia. Simulations were performed to investigate the effects of different dosing intervals on exposure and time above MIC in various degrees of renal impairment.Results
The plasma concentrations from 47 patients were adequately described by a two compartment model with simultaneous fit of ampicillin and sulbactam PK data, where creatinine clearance on clearance and body weight on volume in the peripheral compartment were identified as covariates for both drugs. Creatinine clearance contributed to reducing inter-individual variability of clearance by 16%. Mean clearance (inter-individual variability) for ampicillin and sulbactam was estimated to be 10.7 l h−1 (14.8%) and 10.4 l h−1 (15.2%), respectively. The time above MIC for each pathogen was generally > 50% of the treatment period. Simulations for exposure and time above MIC supported currently recommended dose adjustments.Conclusions
This study provided a PK model for ampicillin and sulbactam, the time above MICs for identified pathogens and associated simulation results. These findings provide useful information and augment evidence for the established dosage regimens in patients with various degrees of renal impairment. 相似文献13.
Zhi-wei Gao Yun-ting Zhu Ming-ming Yu Bin Zan Jia Liu Yi-fan Zhang Xiao-yan Chen Xue-ning Li Da-fang Zhong 《Acta pharmacologica Sinica》2015,36(12):1528-1536
Aim:
TPN729MA is a novel selective PDE5 inhibitor currently under clinical development in China for the treatment of erectile dysfunction. In this study we characterized its preclinical pharmacokinetics (PK) and predict its human PK using a physiologically based pharmacokinetic (PBPK) model.Methods:
The preclinical PK of TPN729MA was studied in rats and dogs. Human clearance (CL) values for TPN729MA were predicted from various allometric methods and from intrinsic CL determined in human liver microsomes. Human PK and plasma concentration versus time profiles of TPN729MA were predicted by using a PBPK model in GastroPlus. Considering the uncertainties in the prediction, a preliminary human study was conducted in 3 healthy male volunteers with an oral dose of 25 mg.Results:
After a single intravenous administration of TPN729MA at a dose of 1 mg/kg in rats and 3 mg/kg in dogs, the plasma CL was 69.7 mL·min−1·kg−1 in rats and 26.3 mL·min−1·kg−1 in dogs, and the steady-state volumes of distribution (Vss) were 7.35 L/kg in rats and 6.48 L/kg in dogs. The oral bioavailability of TPN729MA was 10% in rats and above 34% in dogs. Profiles of predicted plasma concentration versus time were similar to those observed in humans at 25 mg, and the predicted Tmax, Cmax and AUC values were within 2-fold of the observed values.Conclusion:
TPN729MA demonstrates good preclinical PK. This compound is a valuable candidate for further clinical development. This study shows the benefits of using a PBPK model to predict PK in humans. 相似文献14.
Na?m Bouazza Vincent Pestre Vincent Jullien Emmanuel Curis Sa?k Urien Dominique Salmon Jean-Marc Tréluyer 《British journal of clinical pharmacology》2012,74(6):971-977
AIMS
This study was performed to describe clindamycin, administered either orally or intravenously, concentration−time courses to patients with osteomyelitis, to study the effects of different covariates on clindamycin pharmacokinetics and to simulate an optimized administration scheme.METHODS
Clindamycin concentrations were measured in 50 patients. A total of 122 plasma concentrations were available (58 from oral administration and 64 from i.v. infusion). A population pharmacokinetic model was developed with MONOLIX 4 software.RESULTS
A one compartment model adequately described the data. Clindamycin clearance increased significantly with body weight (BW). The typical population estimates (interindividual variability) for clearance, volume of distribution and absorption rate constant were 16.2 l h−1 (0.39), 70.2 l and 0.92 h−1, respectively. The bioavailability of the oral form was estimated to be 87.6%. According to BW, theoretical doses needed to reach a Cmin of 2 mg l−1 were then calculated.CONCLUSIONS
The current recommendation of 600 mg three times daily seems to be effective up to 75 kg but the dose should be raised to 900 mg three times daily thereafter. These assumptions should be prospectively confirmed. 相似文献15.
AIMS
To model the basic pharmacokinetic (PK) characteristics of maraviroc to construct an integrated semi-mechanistic PK model for use in later population PK analyses.METHODS
Three analyses were performed utilizing intravenous, oral and radiolabel data. Firstly, a PK disposition model was developed from data from 20 healthy males who received 3, 10 or 30 mg of intravenous maraviroc. Secondly, a sigmoid Emaxvs dose model of dose-normalized non-compartmental AUC from oral dosing in 134 healthy young males and females across five phase 1 studies was constructed. This described absorption dose non-linearities and tested for the influence of food, formulation and dose frequency on model parameters. The third analysis developed a mass balance model for both absorption and disposition of maraviroc with 300 mg solution and predicted the mass balance after administration of 100 mg tablet formulation.RESULTS
A four-compartment PK model best described the intravenous data and no influence of dose was found on clearance. Total clearance was 48 l h−1 (2.2% SE). The main covariate effect in the non-compartmental analysis reproduced the dose-dependency of food through a five-fold increase in the ED50 of the sigmoid Emax model. The mass balance models calculated that 33.3% and 22.9% of 300 mg solution and 100 mg tablet doses, respectively, are systemically available, and first-pass metabolism extracts 62% of an absorbed dose, estimating a hepatic blood flow of 101 l h−1.CONCLUSIONS
The analysis demonstrates a novel integration approach to build a maraviroc semi-mechanistic population PK model for further use in volunteers and patients. 相似文献16.
Paul Rolan Jacqueline A Gibbons Lin He Eppie Chang Drew Jones Matthew I Gross Jennifer Bahr Davidson Laura M Sanftner Kirk W Johnson 《British journal of clinical pharmacology》2008,66(6):792-801
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT
- Ibudilast is an oral drug approved in Asia for asthma.
- Tolerability of 10-mg regimens has been described previously.
- Published pharmacokinetics (PK) are limited: single or 7-day repeat oral administration of 10 mg in healthy male Asian volunteers.
WHAT THIS STUDY ADDS
- Safety/tolerability and PK of a single 30-mg dose and a 30-mg twice daily (b.i.d.) 2-week regimen in male and female healthy volunteers.
- Higher-dose regimens are relevant for testing in new neurological indications.
- LC-MS/MS analytics for quantification of plasma and urine levels of ibudilast parent and its primary metabolite (6,7-dihydrodiol-ibudilast).
AIMS
To investigate the safety, tolerability and pharmacokinetics (PK) of ibudilast after a single-dose and a multiple-dose regimen.METHODS
Healthy adult male (n = 9) and female (n = 9) volunteers were evaluated over a 17-day stay in a Phase 1 unit. Subjects were randomized 1 : 3 to either oral placebo or ibudilast at 30-mg single administration followed by 14 days of 30 mg b.i.d. Complete safety analyses were performed and, for PK, plasma and urine samples were analysed for ibudilast and its major metabolite.RESULTS
Ibudilast was generally well tolerated. No serious adverse events occurred. Treatment-related adverse events included hyperhidrosis, headache and nausea. Two subjects discontinued after a few days at 30 mg b.i.d. because of vomiting. Although samples sizes were too small to rule out a sex difference, PK were similar in men and women. The mean half-life for ibudilast was 19 h and median Tmax was 4–6 h. Mean (SD) steady-state plasma Cmax and AUC0–24 were 60 (25) ng ml−1 and 1004 (303) ng h ml−1, respectively. Plasma levels of 6,7- dihydrodiol-ibudilast were approximately 30% of the parent.CONCLUSIONS
Ibudilast is generally well tolerated in healthy adults when given as a single oral dose of 30 mg followed by 30 mg b.i.d. (60 mg day−1) for 14 days. Plasma PK reached steady state within 2 days of starting the b.i.d. regimen. Exposure to ibudilast was achieved of a magnitude comparable to that associated with efficacy in rat chronic pain models. 相似文献17.
Francine A de Castro Chiara Piana Belinda P Sim?es Vera L Lanchote O Della Pasqua 《British journal of clinical pharmacology》2015,80(4):618-629
Aim
The aim of this investigation was to develop a model-based dosing algorithm for busulfan and identify an optimal sampling scheme for use in routine clinical practice.Methods
Clinical data from an ongoing study (n = 29) in stem cell transplantation patients were used for the purposes our analysis. A one compartment model was selected as basis for sampling optimization and subsequent evaluation of a suitable dosing algorithm. Internal and external model validation procedures were performed prior to the optimization steps using ED-optimality criteria. Using systemic exposure as parameter of interest, dosing algorithms were considered for individual patients with the scope of minimizing the deviation from target range as determined by AUC(0,6 h).Results
Busulfan exposure after oral administration was best predicted after the inclusion of adjusted ideal body weight and alanine transferase as covariates on clearance. Population parameter estimates were 3.98 h–1, 48.8 l and 12.3 l h–1 for the absorption rate constant, volume of distribution and oral clearance, respectively. Inter-occasion variability was used to describe the differences between test dose and treatment. Based on simulation scenarios, a dosing algorithm was identified, which ensures target exposure values are attained after a test dose. Moreover, our findings show that a sparse sampling scheme with five samples per patient is sufficient to characterize the pharmacokinetics of busulfan in individual patients.Conclusion
The use of the proposed dosing algorithm in conjunction with a sparse sampling scheme may contribute to considerable improvement in the safety and efficacy profile of patients undergoing treatment for stem cell transplantation. 相似文献18.
Callies S André V Patel B Waters D Francis P Burgess M Lahn M 《British journal of clinical pharmacology》2011,71(3):416-428
AIMS
To predict the concentration and target inhibition profiles of the survivin inhibitor antisense oligonucleotide LY2181308 in humans.METHODS
An indirect pharmacokinetic/pharmacodynamic (PK/PD) model was built to predict the inhibition of survivin mRNA and protein in humans following LY2181308 dosing. Plasma and tissue PK data from cynomolgus monkeys were analyzed by non-linear mixed effect modelling techniques. Human PK parameters were predicted using allometric scaling. Assumptions about the pharmacodynamic parameters were made based upon the target and tumour growth inhibition data from mouse xenograft models. This enabled the prediction of the clinical PK/PD profiles.RESULTS
Following a 750 mg dose, LY2181308 tumour concentrations ranging from 18.8 to 54 µg g−1 were predicted to lead to 50 to 90% target inhibition. In humans, LY2181308 tumour concentrations from 13.9 to 52.8 µg g−1 (n = 4, LY2181308 750 mg) were observed associated with a median survivin mRNA and protein inhibition of 20% ± 34 (SD) (n = 9) and 23% ± 63 (SD) (n = 10), respectively. The human PK parameters were adequately estimated: central Vd, 4.09 l (90% CI, 3.6, 4.95), distribution clearances, 2.54 (2.36, 2.71), 0.0608 (0.033, 0.6) and 1.67 (1.07, 2.00) l h−1, peripheral Vds, 25 900 (19 070, 37 200), 0.936 (0.745, 2.07) and 2.51 (1.01, 2.922) l, mean elimination clearance 23.1 l h−1 (5.6, 33.4) and mean terminal half-life, 32.7 days (range 22–52 days).CONCLUSION
The model reasonably predicted LY2181308 PK in humans. Overall, the integration of preclinical PK/PD data enabled to appropriately predict dose and dosing regimen of LY2181308 in humans with pharmacologically relevant survivin inhibition achieved at 750 mg. 相似文献19.
Herman GA Mistry GC Yi B Bergman AJ Wang AQ Zeng W Chen L Snyder K Ruckle JL Larson PJ Davies MJ Langdon RB Gottesdiener KM Wagner JA 《British journal of clinical pharmacology》2011,71(3):429-436
AIMS
Sitagliptin is a selective inhibitor of dipeptidyl peptidase-4 (DPP-4) used to treat type 2 diabetes. The present aim was to evaluate pharmacokinetic (PK), pharmacodynamic (PD) and safety characteristics of sitagliptin following single doses in healthy, young Japanese males.METHODS
In this alternating two-panel, randomized, controlled double-blind study, six healthy Japanese male subjects (aged 20–46 years) in each panel received single oral doses of 5–400 mg sitagliptin and two received placebo. Plasma and urine drug concentrations were measured from 0–48 h post dose and plasma DPP-4 inhibition from 0–24 h post dose. The results were compared with historical data from young, healthy non-Japanese males.RESULTS
Plasma concentrations of sitagliptin increased approximately in proportion to dose; maximum concentrations occurred 2–6 h post-dose. The mean apparent terminal half-life for plasma sitagliptin was 9–14 h, with the half-life slightly decreasing as the dose increased. The mean dose fraction excreted unchanged in the urine was 0.73–1.00. Ingestion of a traditional Japanese breakfast prior to dosing had only a minor effect on PK parameters. After correction for dilution and competition effects during assay, doses of sitagliptin ≥50 mg resulted in weighted average DPP-4 inhibition from 0–24 h post-dose >94% (without correction, >78%). No clinically meaningful differences in PK and DPP-4 inhibition parameters were found between Japanese and non-Japanese subjects. Sitagliptin was generally well tolerated and there were no serious adverse experiences or episodes of hypoglycaemia.CONCLUSIONS
The PK and PD findings from this study are consistent with once daily dosing of sitagliptin in Japanese patients with type 2 diabetes. 相似文献20.
Joerg J Moehrle Stephan Duparc Christoph Siethoff Paul L M Giersbergen J Carl Craft Sarah Arbe-Barnes Susan A Charman Maria Gutierrez Sergio Wittlin Jonathan L Vennerstrom 《British journal of clinical pharmacology》2013,75(2):524-537