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Montepiedra G, Svensson EM, Wong WK, Hooker AC. Optimizing the design of a pharmacokinetic trial to evaluate the dosing scheme of a novel tuberculosis drug in children living with or without HIV. CPT Pharmacometrics Syst Pharmacol 2024; 13:270-280. [PMID: 37946698 PMCID: PMC10864936 DOI: 10.1002/psp4.13077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 09/25/2023] [Accepted: 10/10/2023] [Indexed: 11/12/2023] Open
Abstract
Pharmacokinetic (PK) studies in children are usually small and have ethical constraints due to the medical complexities of drawing blood in this special population. Often, population PK models for the drug(s) of interest are available in adults, and these models can be extended to incorporate the expected deviations seen in children. As a consequence, there is increasing interest in the use of optimal design methodology to design PK sampling schemes in children that maximize information using a small sample size and limited number of sampling times per dosing period. As a case study, we use the novel tuberculosis drug delamanid, and show how applications of optimal design methodology can result in highly efficient and model-robust designs in children for estimating PK parameters using a limited number of sampling measurements. Using developed population PK models based on available data from adults living with and without HIV, and limited data on children without HIV, competing designs for children living with HIV were derived and assessed based on robustness to model uncertainty.
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Affiliation(s)
| | - Elin M. Svensson
- Department of PharmacyRadboud University Medical CenterNijmegenThe Netherlands
- Department of PharmacyUppsala UniversityUppsalaSweden
| | - Weng Kee Wong
- University of California Los AngelesLos AngelesCaliforniaUSA
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Ruel HLM, Watanabe R, Evangelista MC, Beauchamp G, Auger JP, Segura M, Steagall PV. Pain burden, sensory profile and inflammatory cytokines of dogs with naturally-occurring neuropathic pain treated with gabapentin alone or with meloxicam. PLoS One 2020; 15:e0237121. [PMID: 33253197 PMCID: PMC7703878 DOI: 10.1371/journal.pone.0237121] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 11/10/2020] [Indexed: 11/20/2022] Open
Abstract
Canine neuropathic pain (NeuP) has been poorly investigated. This study aimed to evaluate the pain burden, sensory profile and inflammatory cytokines in dogs with naturally-occurring NeuP. Twenty-nine client-owned dogs with NeuP were included in a prospective, partially masked, randomized crossover clinical trial, and treated with gabapentin/placebo/gabapentin-meloxicam or gabapentin-meloxicam/placebo/gabapentin (each treatment block of 7 days; total 21 days). Pain scores, mechanical (MNT) and electrical (ENT) nociceptive thresholds and descending noxious inhibitory controls (DNIC) were assessed at baseline, days 7, 14, and 21. DNIC was evaluated using ΔMNT (after-before conditioning stimulus). Positive or negative ΔMNT corresponded to inhibitory or facilitatory pain profiles, respectively. Pain scores were recorded using the Client Specific Outcome Measures (CSOM), Canine Brief Pain Inventory (CBPI), and short-form Glasgow Composite Measure Pain Scale (CMPS-SF). Data from baseline were compared to those of sixteen healthy controls. ΔMNT, but not MNT and ENT, was significantly larger in controls (2.3 ± 0.9 N) than in NeuP (-0.2 ± 0.7 N). The percentage of dogs with facilitatory sensory profile was similar at baseline and after placebo (61.5–63%), and between controls and after gabapentin (33.3–34.6%). The CBPI scores were significantly different between gabapentin (CBPI pain and CBPI overall impression) and/or gabapentin-meloxicam (CBPI pain and interference) when compared with baseline, but not placebo. The CBPI scores were not significantly different between placebo and baseline. The concentration of cytokines was not different between groups or treatments. Dogs with NeuP have deficient inhibitory pain mechanisms. Pain burden was reduced after gabapentin and/or gabapentin-meloxicam when compared with baseline using CBPI and CMPS-SF scores. However, these scores were not superior than placebo, nor placebo was superior to baseline evaluations. A caregiver placebo effect may have biased the results.
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Affiliation(s)
- Hélène L. M. Ruel
- Department of Clinical Sciences, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Ryota Watanabe
- Department of Clinical Sciences, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Marina C. Evangelista
- Department of Clinical Sciences, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Guy Beauchamp
- Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Jean-Philippe Auger
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Mariela Segura
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Paulo V. Steagall
- Department of Clinical Sciences, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
- * E-mail:
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Adrian D, Papich MG, Baynes R, Stafford E, Lascelles BDX. The pharmacokinetics of gabapentin in cats. J Vet Intern Med 2018; 32:1996-2002. [PMID: 30307652 PMCID: PMC6271300 DOI: 10.1111/jvim.15313] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 06/21/2018] [Accepted: 07/31/2018] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Gabapentin is the most commonly prescribed medication for the treatment of chronic musculoskeletal pain in cats. Despite this common and chronic usage, clinically relevant pharmacokinetic data is lacking. OBJECTIVES To evaluate the pharmacokinetics of clinically relevant dosing regimens of gabapentin in cats. ANIMALS Eight research-purpose mixed-breed cats. METHODS Cats were enrolled in a serial order, non-randomized pharmacokinetic study. Gabapentin was administered as an IV bolus (5 mg/kg), orally (10 mg/kg) as a single dose or twice daily for 2 weeks, or as a transdermal gel (10 mg/kg) in serial order. Serial blood samples were collected up to 48 hours. Plasma concentrations were determined using Ultra Performance Liquid Chromatography-Mass Spectrometry. Compartmental analysis was used to generate gabapentin time-concentration models. RESULTS After IV administration CL (median (range)) and terminal half-life were 160.67 mL/kg*hr (119.63-199.11) and 3.78 hours (3.12-4.47), respectively. The oral terminal half-life was 3.63 hours (2.96-4.77), and 3.72 hours (3.12-4.51) for single and repeated dosing. TMAX and CMAX , as predicted by the model were 1.05 hours (0.74-2.11), and 12.42 μg/mL (8.31-18.35) after single oral dosing, and 0.77 hours (0.58-1.64), and 14.78 μg/mL (9.70-18.41) after repeated oral dosing. Bioavailability after a single oral dose was 94.77% (82.46-122.83). IMPORTANCE Repeated oral dosing of gabapentin did not alter the drug's pharmacokinetics, making dose adjustments unnecessary with long-term treatment. As prepared, the transdermal route is an inappropriate choice for drug administration. These relevant data are important for future studies evaluating potential efficacy of the medication for treating chronic pain states in cats.
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Affiliation(s)
- Derek Adrian
- Comparative Pain Research and Education Centre, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina.,Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina
| | - Mark G Papich
- Molecular and Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Ronald Baynes
- Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Emma Stafford
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina.,Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina.,Veterinary Clinical Pharmacy, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - B Duncan X Lascelles
- Comparative Pain Research and Education Centre, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina.,Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina.,Center for Pain Research and Innovation, UNC School of Dentistry, Chapel Hill, North Carolina.,Center for Translational Pain Research, Department of Anesthesiology, Duke University, Durham, North Carolina
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Adrian D, Papich M, Baynes R, Murrell J, Lascelles BDX. Chronic maladaptive pain in cats: A review of current and future drug treatment options. Vet J 2017; 230:52-61. [PMID: 28887012 DOI: 10.1016/j.tvjl.2017.08.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 08/10/2017] [Accepted: 08/17/2017] [Indexed: 11/28/2022]
Abstract
Despite our increasing understanding of the pathophysiology underlying chronic or maladaptive pain, there is a significant gap in our ability to diagnose and treat the condition in domestic cats. Newer techniques being used to identify abnormalities in pain processing in the cat include validated owner questionnaires, measurement of movement and activity, and measurement of sensory thresholds and somatomotor responses. While some data are available evaluating possible therapeutics for the treatment of chronic pain in the cat, most data are limited to normal cats. This review details our current understanding of chronic or maladaptive pain, techniques for the detection and measurement of the condition and the associated central nervous changes, as well as an overview of the data evaluating potential therapeutics in cats.
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Affiliation(s)
- Derek Adrian
- Comparative Pain Research and Education Centre, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Mark Papich
- Molecular and Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Ron Baynes
- Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Jo Murrell
- School of Veterinary Sciences, University of Bristol, Bristol, UK
| | - B Duncan X Lascelles
- Comparative Pain Research and Education Centre, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA; Center for Pain Research and Innovation, UNC School of Dentistry, Chapel Hill, NC, USA; Center for Translational Pain Research, Department of Anesthesiology, Duke University, Durham, NC, USA.
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Papathanasiou T, Juul RV, Gabel-Jensen C, Kreilgaard M, Lund TM. Population Pharmacokinetic Modelling of Morphine, Gabapentin and their Combination in the Rat. Pharm Res 2016; 33:2630-43. [PMID: 27380190 DOI: 10.1007/s11095-016-1988-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 06/28/2016] [Indexed: 10/21/2022]
Abstract
PURPOSE The combination of morphine and gabapentin seems promising for the treatment of postoperative and neuropathic pain. Despite the well characterised pharmacodynamic interaction, little is known about possible pharmacokinetic interactions. The aim of this study was to evaluate whether co-administration of the two drugs leads to modifications of their pharmacokinetic profiles. METHODS The pharmacokinetics of morphine, morphine-3-glucuronide and gabapentin were characterised in rats following subcutaneous injections of morphine, gabapentin or their combination. Non-linear mixed effects modelling was applied to describe the pharmacokinetics of the compounds and possible interactions. RESULTS The plasma-concentration-time profiles of morphine and gabapentin were best described using a three- and a one-compartment disposition model respectively. Dose dependencies were found for morphine absorption rate and gabapentin bioavailability. Enterohepatic circulation of morphine-3-glucuronide was modelled using an oscillatory model. The combination did not lead to pharmacokinetic interactions for morphine or gabapentin but resulted in an estimated ~33% diminished morphine-3-glucuronide formation. CONCLUSIONS The finding of a lack of pharmacokinetic interaction strengthens the notion that the combination of the two drugs leads to better efficacy in pain treatment due to interaction at the pharmacodynamic level. The interaction found between gabapentin and morphine-3-glucuronide, the latter being inactive, might not have any clinical relevance.
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Affiliation(s)
- Theodoros Papathanasiou
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences,, University of Copenhagen, Universitetsparken 2, DK-2100, Copenhagen, Denmark
| | - Rasmus Vestergaard Juul
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences,, University of Copenhagen, Universitetsparken 2, DK-2100, Copenhagen, Denmark
| | - Charlotte Gabel-Jensen
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mads Kreilgaard
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences,, University of Copenhagen, Universitetsparken 2, DK-2100, Copenhagen, Denmark
| | - Trine Meldgaard Lund
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences,, University of Copenhagen, Universitetsparken 2, DK-2100, Copenhagen, Denmark.
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Pharmacokinetic/Pharmacodynamic Relationship of Gabapentin in a CFA-induced Inflammatory Hyperalgesia Rat Model. Pharm Res 2016; 33:1133-43. [DOI: 10.1007/s11095-016-1859-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 01/11/2016] [Indexed: 11/25/2022]
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Taneja A, Troconiz IF, Danhof M, Della Pasqua O. Semi-mechanistic modelling of the analgesic effect of gabapentin in the formalin-induced rat model of experimental pain. Pharm Res 2013; 31:593-606. [PMID: 24096967 DOI: 10.1007/s11095-013-1183-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2013] [Accepted: 08/09/2013] [Indexed: 12/27/2022]
Abstract
PURPOSE The formalin-induced rat model of nociception involves moderate continuous pain. Formalin-induced pain results in a typical repetitive flinching behaviour, which displays a biphasic pattern characterised by peaks of pain. Here we described the time course of pain response and the analgesic effect of gabapentin using a semi-mechanistic modelling approach. METHODS Male Sprague-Dawley rats received gabapentin (10-100 mg/kg) or placebo 1 h prior to the formalin injection, as per standard protocol. A reduction in the frequency of the second peak of flinching was used as a behavioural measure of gabapentin-mediated anti-nociception. The flinching response was modelled using a mono-exponential function to characterise the first peak and an indirect response model with a time variant synthesis rate for the second. PKPD modelling was performed using a population approach in NONMEM v.7.1.2. RESULTS The time course of the biphasic response was adequately described by the proposed model, which included separate expressions for each phase. Gabapentin was found to reversibly decrease, but not suppress the flinching frequency of the second response peak only. The mean IC50 estimate was 7,510 ng/ml, with relative standard error (RSE%) of 40%. CONCLUSIONS A compartmental, semi-mechanistic model provides the basis for further understanding of the formalin-induced flinching response and consequently to better characterisation of the properties of gabapentin, such as the potency in individual animals. Moreover, despite high exposure levels, model predictions show that gabapentin does not completely suppress behavioural response in the formalin-induced pain model.
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Affiliation(s)
- A Taneja
- Division of Pharmacology, Leiden Academic Centre for Drug Research, POBox 9502, 2300 RA, Leiden, The Netherlands
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Taneja A, Nyberg J, Danhof M, Della Pasqua O. Optimised protocol design for the screening of analgesic compounds in neuropathic pain. J Pharmacokinet Pharmacodyn 2012. [PMID: 23197246 DOI: 10.1007/s10928-012-9277-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We have previously shown how screening experiments for neuropathic pain can be optimised taking into account parameter and model uncertainty. Here we demonstrate how optimised protocols can be used to screen and rank candidate molecules. The concept is illustrated by pregabalin as a new chemical entity and gabapentin as a reference compound. ED-optimality was applied to a logistic regression model describing the relationship between drug exposure and response to evoked pain in the complete Freund's adjuvant (CFA) model in rats. Design variables for optimisation of the experimental protocol included dose levels and sampling times. Prior information from the reference compound was used in conjunction with relative in vitro potency as priors. Results from simulated scenarios were then combined with fitting of experimental data to estimate precision and bias of model parameters for the empirical and optimised designs. The pharmacokinetics of pregabalin was described by a two-compartment model. The expected value of EC(50) of pregabalin was 637.5 ng ml(-1). Model-based analysis of the data yielded median (range) of EC(50) values of 1,125 (898-2412) ng ml(-1) for the empirical protocol and 755 (189-756) ng ml(-1) for the optimised design. In contrast to current practice, optimal design entails different sampling schedule across dose levels. ED-optimised designs should become standard practice in the screening of candidate molecules. It ensures lower bias when estimating the drug potency, facilitating accurate ranking and selection of compounds for further development.
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Affiliation(s)
- A Taneja
- Division of Pharmacology, LACDR, Leiden University, Leiden, The Netherlands
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