1
|
Cha DS, Kleine N, Teopiz KM, Di Vincenzo JD, Ho R, Galibert SL, Samra A, Zilm SPM, Cha RH, d'Andrea G, Gill H, Ceban F, Meshkat S, Wong S, Le GH, Kwan ATH, Rosenblat JD, Rhee TG, Mansur RB, McIntyre RS. The efficacy of zuranolone in postpartum depression and major depressive disorder: a review & number needed to treat (NNT) analysis. Expert Opin Pharmacother 2024; 25:5-14. [PMID: 38164653 DOI: 10.1080/14656566.2023.2298340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 12/19/2023] [Indexed: 01/03/2024]
Abstract
INTRODUCTION Major depressive disorder (MDD) is a common and debilitating mental illness. Postpartum depression (PPD) impacts women globally and is one of the most common complications of childbirth that is underdiagnosed and undertreated, adversely impacting the mental health of women, children, and partners.Available antidepressant medications require weeks to months before showing effect. In this setting, zuranolone, an oral neuroactive steroid and a positive allosteric modulator of GABAA receptors, is an attractive alternative as a rapid-acting antidepressant treatment. AREAS COVERED This article reviews zuranolone (SAGE217), focusing on available clinical studies in individuals with PPD and MDD. This paper adds to the extant literature by presenting the efficacy data as Number Needed to Treat (NNT) to facilitate indirect comparisons with other antidepressants. EXPERT OPINION Zuranolone is a novel rapid-acting (i.e. two week course) oral antidepressant for the treatment of adults with PPD with ongoing clinical trials evaluating its efficacy in adults with MDD. Zuranolone is well tolerated with no significant safety concerns in any clinical trials completed to date. Zuranolone will be scheduled by the Drug Enforcement Agency (DEA).
Collapse
Affiliation(s)
- Danielle S Cha
- Royal Brisbane & Women's Hospital, Mental Health Services, Brisbane, Queensland, Australia
- School of Clinical Medicine - Royal Brisbane Clinical Unit, University of Queensland, Brisbane, Queensland, Australia
- Brain and Cognition Foundation, Toronto, ON, Canada
- Mood Disorders Psychopharmacology Department, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
- Royal Brisbane & Women's Hospital, Metro North Hospital and Health Service, Brisbane, Queensland, Australia
| | - Nicholas Kleine
- Mood Disorders Psychopharmacology Department, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
- Department of Pharmacology, University of Toronto, Toronto, Canada
| | - Kayla M Teopiz
- Mood Disorders Psychopharmacology Department, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
- Department of Pharmacology, University of Toronto, Toronto, Canada
| | - Joshua D Di Vincenzo
- Brain and Cognition Foundation, Toronto, ON, Canada
- Mood Disorders Psychopharmacology Department, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| | - Roger Ho
- Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore, Singapore
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio", Chieti, Italy
| | - Stephanie L Galibert
- Department of Obstetrics and Gynaecology, Logan Hospital, Logan, Queensland, Australia
| | - Amrita Samra
- Royal Brisbane & Women's Hospital, Metro North Hospital and Health Service, Brisbane, Queensland, Australia
| | - Samuel P M Zilm
- Royal Brisbane & Women's Hospital, Metro North Hospital and Health Service, Brisbane, Queensland, Australia
| | - Rebekah H Cha
- Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Giacomo d'Andrea
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. D'Annunzio", Chieti, Italy
| | - Hartej Gill
- Brain and Cognition Foundation, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Felicia Ceban
- Brain and Cognition Foundation, Toronto, ON, Canada
- Mood Disorders Psychopharmacology Department, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
- Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
| | | | - Sabrina Wong
- Brain and Cognition Foundation, Toronto, ON, Canada
- Mood Disorders Psychopharmacology Department, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| | - Gia Han Le
- Brain and Cognition Foundation, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Angela T H Kwan
- Brain and Cognition Foundation, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Joshua D Rosenblat
- Brain and Cognition Foundation, Toronto, ON, Canada
- Mood Disorders Psychopharmacology Department, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto
| | - Taeho Greg Rhee
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
- Department of Public Health Sciences, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Rodrigo B Mansur
- Brain and Cognition Foundation, Toronto, ON, Canada
- Mood Disorders Psychopharmacology Department, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| | - Roger S McIntyre
- Department of Psychiatry and Pharmacology, University of Toronto, Toronto, Canada
- Brain and Cognition Discovery Foundation (BCDF), Toronto, ON, Canada
- Board Chair, Depression and Bipolar Support Alliance (DBSA) Board of Directors, Chicago, IL, USA
- Guangzhou Medical University, Guangzhou, GD, China
- College of Medicine, Korea University, Seoul, Republic of Korea
- College of Medicine, University of the Philippines, Manila, Philippines
- State University of New York (SUNY) Upstate Medical University, Syracuse, NY, USA
- Department of Psychiatry and Neurosciences, University of California School of Medicine, Riverside, CA, USA
| |
Collapse
|
2
|
Manzella FM, Cabrera OH, Wilkey D, Fine-Raquet B, Klawitter J, Krishnan K, Covey DF, Jevtovic-Todorovic V, Todorovic SM. Sex-specific hypnotic effects of the neuroactive steroid (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile are mediated by peripheral metabolism into an active hypnotic steroid. Br J Anaesth 2023; 130:154-164. [PMID: 36428160 PMCID: PMC10080470 DOI: 10.1016/j.bja.2022.09.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 08/01/2022] [Accepted: 09/24/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND The novel synthetic neuroactive steroid (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile (3β-OH) blocks T-type calcium channels but does not directly modulate neuronal γ-aminobutyric acid type A (GABAA) currents like other anaesthetic neurosteroids. As 3β-OH has sex-specific hypnotic effects in adult rats, we studied the mechanism contributing to sex differences in its effects. METHODS We used a combination of behavioural loss of righting reflex, neuroendocrine, pharmacokinetic, in vitro patch-clamp electrophysiology, and in vivo electrophysiological approaches in wild-type mice and in genetic knockouts of the CaV3.1 T-type calcium channel isoform to study the mechanisms by which 3β-OH and its metabolite produces sex-specific hypnotic effects. RESULTS Adult male mice were less sensitive to the hypnotic effects of 3β-OH compared with female mice, and these differences appeared during development. Adult males had higher 3β-OH brain concentrations despite being less sensitive to its hypnotic effects. Females metabolised 3β-OH into the active GABAA receptor positive allosteric modulator (3α,5β,17β)-3-hydroxyandrostane-17-carbonitrile (3α-OH) to a greater extent than males. The 3α-OH metabolite has T-channel blocking properties with sex-specific hypnotic and pharmacokinetic effects. Sex-dependent suppression of the cortical electroencephalogram is more pronounced with 3α-OH compared with 3β-OH. CONCLUSIONS The sex-specific differences in the hypnotic effect of 3β-OH in mice are attributable to differences in its peripheral metabolism into the more potent hypnotic metabolite 3α-OH.
Collapse
Affiliation(s)
- Francesca M Manzella
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Omar H Cabrera
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Davis Wilkey
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Brier Fine-Raquet
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Jelena Klawitter
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Kathiresan Krishnan
- Department of Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Douglas F Covey
- Department of Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA; Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Vesna Jevtovic-Todorovic
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Slobodan M Todorovic
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
| |
Collapse
|
3
|
Lambert PM, Ni R, Benz A, Rensing NR, Wong M, Zorumski CF, Mennerick S. Non-sedative cortical EEG signatures of allopregnanolone and functional comparators. Neuropsychopharmacology 2023; 48:371-379. [PMID: 36168047 PMCID: PMC9751067 DOI: 10.1038/s41386-022-01450-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 08/13/2022] [Accepted: 08/31/2022] [Indexed: 12/26/2022]
Abstract
Neurosteroids that positively modulate GABAA receptors are among a growing list of rapidly acting antidepressants, including ketamine and psychedelics. To develop increasingly specific treatments with fewer side effects, we explored the possibility of EEG signatures in mice, which could serve as a cross-species screening tool. There are few studies of the impact of non-sedative doses of rapid antidepressants on EEG in either rodents or humans. Here we hypothesize that EEG features may separate a rapid antidepressant neurosteroid, allopregnanolone, from other GABAA positive modulators, pentobarbital and diazepam. Further, we compared the actions GABA modulators with those of ketamine, an NMDA antagonist and prototype rapid antidepressant. We examined EEG spectra during active exploration at two cortical locations and examined cross-regional and cross-frequency interactions. We found that at comparable doses, the effects of allopregnanolone, despite purported selectivity for certain GABAAR subtypes, was indistinguishable from pentobarbital during active waking exploration. The actions of diazepam had recognizable common features with allopregnanolone and pentobarbital but was also distinct, consistent with subunit selectivity of benzodiazepines. Finally, ketamine exhibited no distinguishing overlap with allopregnanolone in the parameters examined. Our results suggest that rapid antidepressants with different molecular substrates may remain separated at the level of large-scale ensemble activity, but the studies leave open the possibility of commonalities in more discrete circuits and/or in the context of a dysfunctional brain.
Collapse
Affiliation(s)
- Peter M Lambert
- Department of Psychiatry, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA.,Medical Scientist Training Program, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Richard Ni
- Department of Psychiatry, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Ann Benz
- Department of Psychiatry, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Nicholas R Rensing
- Department of Neurology, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Michael Wong
- Department of Neurology, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Charles F Zorumski
- Department of Psychiatry, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA.,Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Steven Mennerick
- Department of Psychiatry, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA. .,Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA.
| |
Collapse
|
4
|
White K, Aldurdunji M, Harris J, Ortori C, Paine S. Alfaxalone population pharmacokinetics in the rat: Model application for pharmacokinetic and pharmacodynamic design in inbred and outbred strains and sexes. Pharmacol Res Perspect 2022; 10:e01031. [PMID: 36380704 PMCID: PMC9667119 DOI: 10.1002/prp2.1031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/30/2022] [Accepted: 10/01/2022] [Indexed: 11/17/2022] Open
Abstract
The translation of new injectable anesthetic drugs from rodent to humans remains slow, despite the realization that reliance on the volatile agents is unsustainable from an environmental perspective. The aim of this study was to investigate the influence of rat sex and strain on the PK and PD of the anesthetic neurosteroid alfaxalone. Forty rats had cannulas inserted under isoflurane anesthesia for drug administration and sampling. Carotid artery blood samples were collected for blood gas analysis, hematology, biochemistry, and plasma concentrations of alfaxalone. Plasma samples were assayed using liquid chromatography-mass spectrometry. Compartmental non-linear mixed effects methods (NLME) models were applied to two rat populations to determine whether body weight, sex, and strain influenced PK parameters. There were significant differences between the sexes for plasma clearance, half-life and mean residence time in Lewis rats, and mean arterial blood pressure was significantly lower in the female rats at 120 min. An initial NLME PK population model was used to design an adjusted alfaxalone infusion for SD females matching plasma concentrations in males and minimizing cardiopulmonary depression but maintaining an appropriate hypnotic effect. A final NLME population model showed that alfaxalone clearance was dependent on both bodyweight and sex, whereas volume of distribution was influenced by strain. NLME PK models offer the advantage of having a single model that describes a population and therefore shares data interpretation between animals unlike the standard deterministic PK approach. This approach can be used to propose bespoke dosing regimens for optimal use of alfaxalone.
Collapse
Affiliation(s)
- Kate White
- School of Veterinary Medicine and ScienceUniversity of NottinghamSutton BoningtonUK
| | - Mohammed Aldurdunji
- School of Veterinary Medicine and ScienceUniversity of NottinghamSutton BoningtonUK,Department of Clinical Pharmacy, College of PharmacyUmm Al‐Qura UniversityMakkahSaudi Arabia
| | - John Harris
- School of BiosciencesUniversity of NottinghamSutton BoningtonUK
| | - Catherine Ortori
- Centre for Analytical Bioscience, Advanced Materials and Healthcare Technologies Division, School of PharmacyUniversity of NottinghamNottinghamUK
| | - Stuart Paine
- School of Veterinary Medicine and ScienceUniversity of NottinghamSutton BoningtonUK
| |
Collapse
|
5
|
Daskalaki M, Drummer C, Behr R, Heistermann M. The use of alfaxalone for short-term anesthesia can confound serum progesterone measurements in the common marmoset: a case report. Primate Biol 2022; 9:23-28. [PMID: 36034474 PMCID: PMC9399913 DOI: 10.5194/pb-9-23-2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 07/01/2022] [Indexed: 11/16/2022] Open
Abstract
Alfaxan® (alfaxalone) is a steroid general anesthetic widely used in veterinary medicine for induction and maintenance of anesthesia in several species. While the use of alfaxalone in veterinary practice has several benefits compared to the use of other anesthetic agents, the fact that it is derived from progesterone may confound the measurement of the latter in the blood of animals under alfaxalone treatment. In the present case study, we report the measurement of serum progesterone in an individual common marmoset (Callithrix jacchus) during five ovarian cycles in which luteolysis was
induced by PGF2α. Blood samples were usually taken from the awake
animal with the exception of the fifth cycle in which the sample was
collected under alfaxalone anesthesia in connection with a tooth extraction. In contrast to the previous four cycles in which luteolysis resulted in the expected marked decrease in progesterone concentrations, the – apparent – progesterone level in the cycle under alfaxalone treatment remained unexpectedly high. Cross-reactivity of the non-specific antibody used in the progesterone assay with alfaxalone most likely explains this finding.
Collapse
Affiliation(s)
- Maria Daskalaki
- Platform Degenerative Diseases, German Primate Center – Leibniz
Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Charis Drummer
- Platform Degenerative Diseases, German Primate Center – Leibniz
Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Rüdiger Behr
- Platform Degenerative Diseases, German Primate Center – Leibniz
Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Michael Heistermann
- Endocrinology Laboratory, German Primate Center – Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| |
Collapse
|
6
|
Li Z, Li Z, Wang B, Liu J. Influence of release rate, dose and co-administration on pharmacokinetics, pharmacodynamics and PK-PD relationship of tanshinone IIA and tanshinol. Eur J Pharm Sci 2022; 168:106042. [PMID: 34656775 DOI: 10.1016/j.ejps.2021.106042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 10/11/2021] [Accepted: 10/12/2021] [Indexed: 11/28/2022]
Abstract
The present study aims to investigate the influence of release rate, dose and co-administration on pharmacokinetics (PK) and pharmacodynamics (PD) of tanshinone IIA (TA) and tanshinol (TS), and reveal the changes in their PK-PD relationships. Sustained and immediate release pellets of TS and TA were prepared respectively, and oral administrated to angina model rabbits according to the experimental design. The administration dose of TS was 50, 35 or 20 mg/kg and that of TA was 30 mg/kg. Then, plasma concentrations of TS and TA were measured to evaluate the pharmacokinetics. Pharmacodynamic biomarkers including cardiac troponin (cTn-I), creatine kinase (CK-MB), superoxide dismutase (SOD) and nitric oxide (NO) were measured to evaluated the effects of cardioprotection, amelioration of oxidative stress and vasorelaxation of TS and TA. Parameters such as maximum plasma concentration (Cmax), maximum effect (Emax), time to Cmax or Emax (TCmax or TEmax), areas under the plasma concentration or effect curves (AUC0-∞ or AUEC) and pharmacodynamic efficiency (EFF) were calculated based on non-compartmental analysis. Beside, PK-PD relationship/hysteresis was evaluated. The TEmax was less sensitive than TCmax to changes in release rate. The Emax, AUEC and EFF showed increasing trend as the decrease of release rate even that the AUC0-∞ showed no significant difference. In addition, slow drug release decreased the magnitude of hysteresis of TS and TA. The sensitivities of Emax and AUEC of four biomarkers to changes in dose were varied and relatively lower than those of Cmax and AUC0-∞. The EFF decreased and the magnitude of hysteresis increased for high dose. The Cmax and AUC0-∞ of TS and TA showed little difference after co-administration. The Emax and AUEC of four biomarkers increased for immediate release pellets (P < 0.05 or P < 0.01) and generally decreased for sustained release pellets (P < 0.05 or P < 0.01) after co-administration. In addition, the magnitudes of hysteresis of four biomarkers decreased for immediate release pellets and generally increased for sustained release pellets after co-administration. In summary, the dissociated and unstable PK-PD relationship should be considered during optimization of dosage forms and regimens to make sure the rationality, safety and efficacy. These findings could also provide some valuable information for the development and clinical therapy of other drugs.
Collapse
Affiliation(s)
- Zhenghua Li
- Department of Pharmaceutics, China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing 210009, China
| | - Ziyi Li
- Department of Pharmaceutics, China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing 210009, China
| | - Bingwei Wang
- Department of Pharmaceutics, China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing 210009, China
| | - Jianping Liu
- Department of Pharmaceutics, China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing 210009, China.
| |
Collapse
|
7
|
Joksimovic SM, Sampath D, Krishnan K, Covey DF, Jevtovic-Todorovic V, Raol YH, Todorovic SM. Differential effects of the novel neurosteroid hypnotic (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile on electroencephalogram activity in male and female rats. Br J Anaesth 2021; 127:435-446. [PMID: 33972091 PMCID: PMC8451239 DOI: 10.1016/j.bja.2021.03.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 03/01/2021] [Accepted: 03/03/2021] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND We recently showed that a neurosteroid analogue, (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile (3β-OH), induced hypnosis in rats. The aim of the present study was to evaluate the hypnotic and anaesthetic potential of 3β-OH further using electroencephalography. METHODS We used behavioural assessment and cortical electroencephalogram (EEG) spectral power analysis to examine hypnotic and anaesthetic effects of 3β-OH (30 and 60 mg kg-1) administered intraperitoneally or intravenously to young adult male and female rats. RESULTS We found dose-dependent sex differences in 3β-OH-induced hypnosis and EEG changes. Both male and female rats responded similarly to i.p. 3β-OH 30 mg kg-1. However, at the higher dose (60 mg kg-1, i.p.), female rats had two-fold longer duration of spontaneous immobility than male rats (203.4 [61.6] min vs 101.3 [32.1] min), and their EEG was suppressed in the low-frequency range (2-6 Hz), in contrast to male rats. Although a sex-dependent hypnotic effect was not confirmed after 30 mg kg-1 i.v., female rats appeared more sensitive to 3β-OH with relatively small changes within delta (1-4 Hz) and alpha (8-13 Hz) bands. Finally, 3β-OH had a rapid onset of action and potent hypnotic/anaesthetic effect after 60 mg kg-1 i.v. in rats of both sexes; however, all female rats and only half of the male rats reached burst suppression, an EEG pattern usually associated with profound inhibition of thalamocortical networks. CONCLUSIONS Based on its behavioural effects and EEG signature, 3β-OH is a potent hypnotic in rats, with female rats being more sensitive than male rats.
Collapse
Affiliation(s)
- Srdjan M Joksimovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA.
| | - Dayalan Sampath
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University System, College Station, TX, USA
| | - Kathiresan Krishnan
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO, USA
| | - Douglas F Covey
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO, USA; Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St Louis, MO, USA
| | - Vesna Jevtovic-Todorovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Yogendra H Raol
- Department of Pediatrics, Division of Neurology, Translational Epilepsy Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Slobodan M Todorovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; Neuroscience Graduate Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| |
Collapse
|
8
|
Althaus AL, Ackley MA, Belfort GM, Gee SM, Dai J, Nguyen DP, Kazdoba TM, Modgil A, Davies PA, Moss SJ, Salituro FG, Hoffmann E, Hammond RS, Robichaud AJ, Quirk MC, Doherty JJ. Preclinical characterization of zuranolone (SAGE-217), a selective neuroactive steroid GABA A receptor positive allosteric modulator. Neuropharmacology 2020; 181:108333. [PMID: 32976892 PMCID: PMC8265595 DOI: 10.1016/j.neuropharm.2020.108333] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 08/26/2020] [Accepted: 09/18/2020] [Indexed: 01/04/2023]
Abstract
Zuranolone (SAGE-217) is a novel, synthetic, clinical stage neuroactive steroid GABAA receptor positive allosteric modulator designed with the pharmacokinetic properties to support oral daily dosing. In vitro, zuranolone enhanced GABAA receptor current at nine unique human recombinant receptor subtypes, including representative receptors for both synaptic (γ subunit-containing) and extrasynaptic (δ subunit-containing) configurations. At a representative synaptic subunit configuration, α1β2γ2, zuranolone potentiated GABA currents synergistically with the benzodiazepine diazepam, consistent with the non-competitive activity and distinct binding sites of the two classes of compounds at synaptic receptors. In a brain slice preparation, zuranolone produced a sustained increase in GABA currents consistent with metabotropic trafficking of GABAA receptors to the cell surface. In vivo, zuranolone exhibited potent activity, indicating its ability to modulate GABAA receptors in the central nervous system after oral dosing by protecting against chemo-convulsant seizures in a mouse model and enhancing electroencephalogram β-frequency power in rats. Together, these data establish zuranolone as a potent and efficacious neuroactive steroid GABAA receptor positive allosteric modulator with drug-like properties and CNS exposure in preclinical models. Recent clinical data support the therapeutic promise of neuroactive steroid GABAA receptor positive modulators for treating mood disorders; brexanolone is the first therapeutic approved specifically for the treatment of postpartum depression. Zuranolone is currently under clinical investigation for the treatment of major depressive episodes in major depressive disorder, postpartum depression, and bipolar depression.
Collapse
Affiliation(s)
- Alison L Althaus
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA.
| | - Michael A Ackley
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Gabriel M Belfort
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Steven M Gee
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Jing Dai
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - David P Nguyen
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Tatiana M Kazdoba
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Amit Modgil
- Department of Neuroscience, Tufts University, Boston, MA, USA
| | - Paul A Davies
- Department of Neuroscience, Tufts University, Boston, MA, USA
| | - Stephen J Moss
- Department of Neuroscience, Tufts University, Boston, MA, USA
| | - Francesco G Salituro
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Ethan Hoffmann
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Rebecca S Hammond
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Albert J Robichaud
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Michael C Quirk
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - James J Doherty
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| |
Collapse
|
9
|
A Comparative Study of Intramuscular Alfaxalone- or Ketamine-Based Anesthetic Mixtures in Gray Squirrels Undergoing Gonadectomy: Clinical and Physiologic Findings. Animals (Basel) 2020; 10:ani10081402. [PMID: 32806590 PMCID: PMC7460254 DOI: 10.3390/ani10081402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 08/11/2020] [Accepted: 08/11/2020] [Indexed: 01/15/2023] Open
Abstract
The gray squirrel is one of the most common invasive species in Europe, whose presence is dangerous for the survival of the European red squirrel. To cope with this biological invasion and to safeguard biodiversity, the LIFE+U-SAVEREDS project aims to protect the red squirrel, by limiting the growth of the current population of gray squirrels and simultaneously promoting their eradication with surgical sterilization. This study compares two different anesthetic protocols, including dexmedetomidine (40 µg/kg) and midazolam (0.3 mg/kg) associated with ketamine (15 mg/kg; n = 25 squirrels) or alfaxalone (5 mg/kg; n = 22 squirrels). A blinded investigator evaluated the quality and onset of sedation, intraoperative anesthesia, and recovery, as well as the physiologic parameters for each animal. Alfaxalone provided a good quality of anesthesia with limited cardiovascular effects (p < 0.05) and good intraoperative myorelaxation. Ketamine induced complete relaxation in a shorter time (p < 0.05) and a rapid (p < 0.001) and excellent (p < 0.05) recovery. Despite the overall superiority of ketamine, alfaxalone appeared to be an adequate alternative anesthetic drug that can be administered without requiring intravascular access. It should be rapidly metabolized and excreted; however, it requires the combination of longer acting sedatives/myorelaxants to prevent a poor recovery quality.
Collapse
|
10
|
Zhu X, Finlay DB, Glass M, Duffull SB. Evaluation of the profiles of CB 1 cannabinoid receptor signalling bias using joint kinetic modelling. Br J Pharmacol 2020; 177:3449-3463. [PMID: 32293708 DOI: 10.1111/bph.15066] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 03/11/2020] [Accepted: 04/01/2020] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND AND PURPOSE Biased agonism describes the ability of ligands to differentially regulate multiple signalling pathways when coupled to a single receptor. Signalling is affected by rapid agonist-induced receptor internalisation. Hence, the conventional use of equilibrium models may not be optimal, because (i) receptor numbers vary with time and, in addition, (ii) some pathways may show non-monotonic profiles over time. EXPERIMENTAL APPROACH Data were available from internalisation, cAMP inhibition and phosphorylation of ERK (pERK) of the cannabinoid-1 (CB1 ) receptor using a concentration series of six CB1 ligands (CP55,940, WIN55,212-2, anandamide, 2-arachidonylglycerol, Δ9 -tetrahydrocannabinol and BAY59,3074). The joint kinetic model of CB1 signalling was developed to simultaneously describe the time-dependent activities in three signalling pathways. Based on the insights from the kinetic model, fingerprint profiles of CB1 ligand bias were constructed and visualised. KEY RESULTS A joint kinetic model was able to capture the signalling profiles across all pathways for the CB1 receptor simultaneously for a system that was not at equilibrium. WIN55,212-2 had a similar pattern as 2-arachidonylglycerol (reference). The other agonists displayed bias towards internalisation compared to cAMP inhibition. However, only Δ9 -tetrahydrocannabinol and BAY59,3074 demonstrated bias in the pERK-cAMP pathway comparison. Furthermore, all the agonists exhibited little preference between internalisation and pERK. CONCLUSION AND IMPLICATIONS This is the first joint kinetic assessment of biased agonism at a GPCR (e.g. CB1 receptor) under non-equilibrium conditions. Kinetic modelling is a natural method to handle time-varying data when traditional equilibria are not present and enables quantification of ligand bias.
Collapse
Affiliation(s)
- Xiao Zhu
- Otago Pharmacometrics Group, School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - David B Finlay
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand.,Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Michelle Glass
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand.,Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Stephen B Duffull
- Otago Pharmacometrics Group, School of Pharmacy, University of Otago, Dunedin, New Zealand
| |
Collapse
|
11
|
Goodchild CS, Serrao JM, Sear JW, Anderson BJ. Pharmacokinetic and Pharmacodynamic Analysis of Alfaxalone Administered as a Bolus Intravenous Injection of Phaxan in a Phase 1 Randomized Trial. Anesth Analg 2020; 130:704-714. [DOI: 10.1213/ane.0000000000004204] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
12
|
Marín P, Belda E, Laredo FG, Torres CA, Hernandis V, Escudero E. Pharmacokinetics and sedative effects of alfaxalone with or without dexmedetomidine in rabbits. Res Vet Sci 2019; 129:6-12. [PMID: 31901533 DOI: 10.1016/j.rvsc.2019.12.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/13/2019] [Accepted: 12/18/2019] [Indexed: 12/21/2022]
Abstract
This study aimed to investigate the specific pharmacokinetic profile and effects of alfaxalone after intravenous (IV) and intramuscular (IM) administration to rabbits and evaluate the potential interaction with dexmedetomidine. The study design was a blinded, randomized crossover with a washout period of 2 weeks. Five New Zealand white rabbits were used. Each animal received single IV and IM injections of alfaxalone at a single dose of 5 mg/kg, and single IV and IM injections of alfaxalone (5 mg/kg) combined with dexmedetomidine (100 μg/kg) administered intramuscularly. Blood samples were collected at predetermined times and analysed by high-performance liquid chromatography. The plasma concentration-time curves were analysed by non-compartmental analysis. Sedation/anaesthesia scores were evaluated by a modified numerical rating scale. At pre-determined time points heart and respiratory rates were measured. Times to sternal recumbency and standing position during the recovery were recorded. Concentrations of alfaxalone alone were very similar (slighty smaller) to concentrations when alfaxalone was combined with dexmedetomidine, after both routes of administration. Dexmedetomidine enhanced and increase the duration of the sedative effects of alfaxalone. In conclusion, alfaxalone administered in rabbits provides rapid and smooth onset of sedation. After IV and IM injections of alfaxalone combined with dexmedetomidine, a longer MRT and a deeper and extended sedation have been obtained compared to alfaxalone alone. Consequently, alfaxalone alone or in combination with dexmedetomidine could be useful to achieve respectively moderate to deep sedation in rabbits.
Collapse
Affiliation(s)
- Pedro Marín
- Department of Pharmacology, Faculty of Veterinary Medicine, University of Murcia, Murcia, Spain.
| | - Eliseo Belda
- Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, University of Murcia, Murcia, Spain
| | - Francisco G Laredo
- Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, University of Murcia, Murcia, Spain
| | - Crhystian A Torres
- Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, University of Murcia, Murcia, Spain
| | - Verónica Hernandis
- Department of Pharmacology, Faculty of Veterinary Medicine, University of Murcia, Murcia, Spain
| | - Elisa Escudero
- Department of Pharmacology, Faculty of Veterinary Medicine, University of Murcia, Murcia, Spain
| |
Collapse
|
13
|
Bradley MP, Doerning CM, Nowland MH, Lester PA. Intramuscular Administration of Alfaxalone Alone and in Combination for Sedation and Anesthesia of Rabbits ( Oryctolagus cuniculus). JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE 2019; 58:216-222. [PMID: 30819274 DOI: 10.30802/aalas-jaalas-18-000078] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
This study compared alfaxalone, alone and in combination with other medications, for sedative and anesthetic properties after intramuscular administration in New Zealand white rabbits. In the main portion of the study, 6 female rabbits were assigned to 5 treatment regimens in a blinded crossover design. Alfaxalone (6 mg/kg IM) was administered alone and in combination with each of the following: 0.3 mg/kg butorphanol; 1 mg/kg midazolam; 0.2 mg/kg dexmedetomidine; and both 0.3 mg/kg butorphanol and 0.2 mg/kg dexmedetomidine. An additional 6 rabbits received 0.2 mg/kg dexmedetomidine for comparison. The median time to onset of recumbency ranged from 2.0 to 5.5 min, with times significantly shorter for animals that received alfaxalone with either midazolam or dexmedetomidine than for those given dexmedetomidine only. Duration of sedation (mean ± 1 SD) was: alfaxalone only, 40 ± 7.3 min; alfaxalone with butorphanol, 47.8 ± 9.9 min; alfaxalone with midazolam, 65.2 ± 6.5 min; alfaxalone with dexmedetomidine, 157.5 ± 22.4 min; alfaxalone with butorphanol and dexmedetomidine, 157.7 ± 22.3 min, and dexmedetomidine only, 93.7 ± 11.9 min. Response to noxious stimuli was absent in 2 of the rabbits given dexmedetomidine only, 4 of those given alfaxalone with dexmedetomidine, and all 6 of the animals dosed with alfaxalone, butorphanol, and dexmedetomidine; this last group displayed the longest absence of a toe-pinch response (57 ± 3 min).
Collapse
Affiliation(s)
- Michael P Bradley
- Unit for Laboratory Animal Medicine; University of Michigan, Ann Arbor, Michigan, USA.
| | - Carolyn M Doerning
- Unit for Laboratory Animal Medicine; University of Michigan, Ann Arbor, Michigan, USA
| | - Megan H Nowland
- Unit for Laboratory Animal Medicine; University of Michigan, Ann Arbor, Michigan, USA
| | - Patrick A Lester
- Unit for Laboratory Animal Medicine; University of Michigan, Ann Arbor, Michigan, USA
| |
Collapse
|
14
|
Cristofoletti R, Rowland M, Lesko LJ, Blume H, Rostami-Hodjegan A, Dressman JB. Past, Present, and Future of Bioequivalence: Improving Assessment and Extrapolation of Therapeutic Equivalence for Oral Drug Products. J Pharm Sci 2018; 107:2519-2530. [DOI: 10.1016/j.xphs.2018.06.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/03/2018] [Accepted: 06/12/2018] [Indexed: 12/28/2022]
|
15
|
A question of time. Vet Anaesth Analg 2018; 45:401-404. [DOI: 10.1016/j.vaa.2018.05.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 05/25/2018] [Accepted: 05/25/2018] [Indexed: 11/17/2022]
|
16
|
Rodrigo-Mocholí D, Escudero E, Belda E, Laredo FG, Hernandis V, Marín P. Pharmacokinetics and effects of alfaxalone after intravenous and intramuscular administration to cats. N Z Vet J 2018; 66:172-177. [DOI: 10.1080/00480169.2018.1455541] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- D Rodrigo-Mocholí
- Faculty of Veterinary Medicine, Department of Veterinary Anaesthesia and Analgesia, University of Sydney, Camperdown, New South Wales, Australia
| | - E Escudero
- Faculty of Veterinary Medicine, Department of Pharmacology, University of Murcia, 30071 Espinardo, Murcia, Spain
| | - E Belda
- Faculty of Veterinary Medicine, Department of Animal Medicine and Surgery, University of Murcia, 30071 Espinardo, Murcia, Spain
| | - FG Laredo
- Faculty of Veterinary Medicine, Department of Animal Medicine and Surgery, University of Murcia, 30071 Espinardo, Murcia, Spain
| | - V Hernandis
- Faculty of Veterinary Medicine, Department of Pharmacology, University of Murcia, 30071 Espinardo, Murcia, Spain
| | - P Marín
- Faculty of Veterinary Medicine, Department of Pharmacology, University of Murcia, 30071 Espinardo, Murcia, Spain
| |
Collapse
|
17
|
van den Brink WJ, Hankemeier T, van der Graaf PH, de Lange ECM. Bundling arrows: improving translational CNS drug development by integrated PK/PD-metabolomics. Expert Opin Drug Discov 2018. [DOI: 10.1080/17460441.2018.1446935] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- W. J. van den Brink
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | - T. Hankemeier
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | - P. H. van der Graaf
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
- Certara QSP, Canterbury Innovation House, Canterbury, United Kingdom
| | - E. C. M. de Lange
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| |
Collapse
|
18
|
White KL, Paine S, Harris J. A clinical evaluation of the pharmacokinetics and pharmacodynamics of intravenous alfaxalone in cyclodextrin in male and female rats following a loading dose and constant rate infusion. Vet Anaesth Analg 2017; 44:865-875. [DOI: 10.1016/j.vaa.2017.01.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
|
19
|
Chakrabarti S, Qian M, Krishnan K, Covey DF, Mennerick S, Akk G. Comparison of Steroid Modulation of Spontaneous Inhibitory Postsynaptic Currents in Cultured Hippocampal Neurons and Steady-State Single-Channel Currents from Heterologously Expressed α1β2γ2L GABA(A) Receptors. Mol Pharmacol 2016; 89:399-406. [PMID: 26769414 DOI: 10.1124/mol.115.102202] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 01/13/2016] [Indexed: 12/18/2022] Open
Abstract
Neuroactive steroids are efficacious modulators of γ-aminobutyric acid type A receptor (GABA(A)) receptor function. The effects of steroids on the GABA(A) receptor are typically determined by comparing steady-state single-channel open probability or macroscopic peak responses elicited by GABA in the absence and presence of a steroid. Due to differences in activation conditions (exposure duration, concentration of agonist), it is not obvious whether modulation measured using typical experimental protocols can be used to accurately predict the effect of a modulator on native receptors under physiologic conditions. In the present study, we examined the effects of 14 neuroactive steroids and analogs on the properties of spontaneous inhibitory postsynaptic currents (sIPSCs) in cultured rat hippocampal neurons. The goal was to determine whether the magnitude of modulation of the decay time course of sIPSCs correlates with the extent of modulation and kinetic properties of potentiation as determined in previous single-channel studies. The steroids were selected to cover a wide range of efficacy on heterologously expressed rat α1β2γ2L GABA(A) receptors, ranging from essentially inert to highly efficacious (strong potentiators of single-channel and macroscopic peak responses). The data indicate a strong correlation between prolongation of the decay time course of sIPSCs and potentiation of single-channel open probability. Furthermore, changes in intracluster closed time distributions were the single best predictor of prolongation of sIPSCs. We infer that the information obtained in steady-state single-channel recordings can be used to forecast modulation of synaptic currents.
Collapse
Affiliation(s)
- Sampurna Chakrabarti
- Department of Anesthesiology (S.C., G.A.), Department of Developmental Biology (M.Q., K.K., D.F.C.), and Department of Psychiatry (S.M.), and the Taylor Family Institute for Innovative Psychiatric Research (D.F.C., S.M., G.A.), Washington University School of Medicine, St. Louis, Missouri
| | - Mingxing Qian
- Department of Anesthesiology (S.C., G.A.), Department of Developmental Biology (M.Q., K.K., D.F.C.), and Department of Psychiatry (S.M.), and the Taylor Family Institute for Innovative Psychiatric Research (D.F.C., S.M., G.A.), Washington University School of Medicine, St. Louis, Missouri
| | - Kathiresan Krishnan
- Department of Anesthesiology (S.C., G.A.), Department of Developmental Biology (M.Q., K.K., D.F.C.), and Department of Psychiatry (S.M.), and the Taylor Family Institute for Innovative Psychiatric Research (D.F.C., S.M., G.A.), Washington University School of Medicine, St. Louis, Missouri
| | - Douglas F Covey
- Department of Anesthesiology (S.C., G.A.), Department of Developmental Biology (M.Q., K.K., D.F.C.), and Department of Psychiatry (S.M.), and the Taylor Family Institute for Innovative Psychiatric Research (D.F.C., S.M., G.A.), Washington University School of Medicine, St. Louis, Missouri
| | - Steven Mennerick
- Department of Anesthesiology (S.C., G.A.), Department of Developmental Biology (M.Q., K.K., D.F.C.), and Department of Psychiatry (S.M.), and the Taylor Family Institute for Innovative Psychiatric Research (D.F.C., S.M., G.A.), Washington University School of Medicine, St. Louis, Missouri
| | - Gustav Akk
- Department of Anesthesiology (S.C., G.A.), Department of Developmental Biology (M.Q., K.K., D.F.C.), and Department of Psychiatry (S.M.), and the Taylor Family Institute for Innovative Psychiatric Research (D.F.C., S.M., G.A.), Washington University School of Medicine, St. Louis, Missouri
| |
Collapse
|
20
|
Danhof M. Kinetics of drug action in disease states: towards physiology-based pharmacodynamic (PBPD) models. J Pharmacokinet Pharmacodyn 2015; 42:447-62. [PMID: 26319673 PMCID: PMC4582079 DOI: 10.1007/s10928-015-9437-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 08/17/2015] [Indexed: 11/26/2022]
Abstract
Gerhard Levy started his investigations on the "Kinetics of Drug Action in Disease States" in the fall of 1980. The objective of his research was to study inter-individual variation in pharmacodynamics. To this end, theoretical concepts and experimental approaches were introduced, which enabled assessment of the changes in pharmacodynamics per se, while excluding or accounting for the cofounding effects of concomitant changes in pharmacokinetics. These concepts were applied in several studies. The results, which were published in 45 papers in the years 1984-1994, showed considerable variation in pharmacodynamics. These initial studies on kinetics of drug action in disease states triggered further experimental research on the relations between pharmacokinetics and pharmacodynamics. Together with the concepts in Levy's earlier publications "Kinetics of Pharmacologic Effects" (Clin Pharmacol Ther 7(3): 362-372, 1966) and "Kinetics of pharmacologic effects in man: the anticoagulant action of warfarin" (Clin Pharmacol Ther 10(1): 22-35, 1969), they form a significant impulse to the development of physiology-based pharmacodynamic (PBPD) modeling as novel discipline in the pharmaceutical sciences. This paper reviews Levy's research on the "Kinetics of Drug Action in Disease States". Next it addresses the significance of his research for the evolution of PBPD modeling as a scientific discipline. PBPD models contain specific expressions to characterize in a strictly quantitative manner processes on the causal path between exposure (in terms of concentration at the target site) and the drug effect (in terms of the change in biological function). Pertinent processes on the causal path are: (1) target site distribution, (2) target binding and activation and (3) transduction and homeostatic feedback.
Collapse
Affiliation(s)
- Meindert Danhof
- Leiden Academic Centre for Drug Research, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands.
| |
Collapse
|
21
|
Warne LN, Beths T, Whittem T, Carter JE, Bauquier SH. A review of the pharmacology and clinical application of alfaxalone in cats. Vet J 2014; 203:141-8. [PMID: 25582797 DOI: 10.1016/j.tvjl.2014.12.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Revised: 11/03/2014] [Accepted: 12/14/2014] [Indexed: 10/24/2022]
Abstract
Alfaxalone-2-hydroxpropyl-β-cyclodextrin (alfaxalone-HPCD) was first marketed for veterinary use in Australia in 2001 and has since progressively became available throughout the world, including the USA, where in 2012 Food and Drug Administration (FDA) registration was granted. Despite the growing body of published works and increasing global availability of alfaxalone-HPCD, the accumulating evidence for its use in cats has not been thoroughly reviewed. The purpose of this review is: (1) to detail the pharmacokinetic properties of alfaxalone-HPCD in cats; (2) to assess the pharmacodynamic properties of alfaxalone-HPCD, including its cardiovascular, respiratory, central nervous system, neuromuscular, hepatic, renal, haematological, blood-biochemical, analgesic and endocrine effects; and (3) to consider the clinical application of alfaxalone-HPCD for sedation, induction and maintenance of anaesthesia in cats. Based on the published literature, alfaxalone-HPCD provides a good alternative to the existing intravenous anaesthetic options for healthy cats.
Collapse
Affiliation(s)
- Leon N Warne
- Translational Research and Clinical Trials (TRACTs), Veterinary Hospital, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Vic 3030, Australia
| | - Thierry Beths
- Translational Research and Clinical Trials (TRACTs), Veterinary Hospital, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Vic 3030, Australia
| | - Ted Whittem
- Translational Research and Clinical Trials (TRACTs), Veterinary Hospital, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Vic 3030, Australia
| | - Jennifer E Carter
- Translational Research and Clinical Trials (TRACTs), Veterinary Hospital, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Vic 3030, Australia
| | - Sébastien H Bauquier
- Translational Research and Clinical Trials (TRACTs), Veterinary Hospital, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Vic 3030, Australia.
| |
Collapse
|
22
|
Christakis I, Georgiou P, Minnion J, Constantinides V, Cuenco J, Scott R, Tan T, Palazzo F, Murphy K, Bloom S. Learning curve of vessel cannulation in rats using cumulative sum analysis. J Surg Res 2014; 193:69-76. [PMID: 25082745 DOI: 10.1016/j.jss.2014.06.048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 06/20/2014] [Accepted: 06/24/2014] [Indexed: 11/16/2022]
Abstract
BACKGROUND Intravascular access routes are widely used for administering agents or taking blood samples in rodents. Vessel cannulation in rats is a technically challenging procedure with a risk for significant complications. The use of cumulative sum (CUSUM) analysis allows continuous monitoring of the performer's outcomes to evaluate the learning curve for a particular procedure. The aim of the present study was to assess a researcher's learning curve in the cannulation of the jugular and femoral vein in rats using CUSUM analysis. MATERIALS AND METHODS A single researcher performed two hundred microsurgical operations between September 2012 and September 2013. The animals (male Wistar rats) were anesthetized with isoflurane whereas the right jugular vein and the left femoral vein were catheterized. Prospective data were collected and analyzed using CUSUM analysis. For the purposes of the study, the rat population was divided in four groups based on the order of studies; group 1 represents the first 50 animals cannulated, group 2 the next batch of 50 animals, and so forth. RESULTS The operating times required for cannulation of the jugular vein for groups 1, 2, 3, and 4 were 24.6 ± 4.8, 15.9 ± 2.5, 15.2 ± 3.2, and 15.7 ± 3.3 min, respectively. Group 1's operating time was significantly longer than all the other groups (P < 0.001 compared with all other groups). The operating times for groups 2, 3, and 4 did not differ significantly (P > 0.05). The cannulation of the femoral vein required a mean of 32 ± 5.3 min for group 1, 24.9 ± 5.7 min for group 2, 18.4 ± 4 min for group 3, and 17.2 ± 3.4 min for group 4. The operating time of group 1 was significantly longer when compared with all groups (P < 0.001 for all groups). Group 2 also had a longer operating time than groups 3 and 4 (P < 0.001 compared with both groups). Groups 3 and 4 did not show any statistical significant difference when their operating time was compared (P > 0.05). CUSUM analysis suggested that the number of cases required to achieve the required experience to most effectively cannulate the jugular and femoral vein is approximately 50 and 100 cases, respectively. The adverse effects of the procedure included two unexpected deaths, both of which occurred in group 1 (0.5% in total). CONCLUSIONS The authors' experience regarding the learning curve of the cannulation of the femoral and jugular vein in rats from 200 animals operated over a period of 1 y for the evaluation of the pharmacokinetic properties of drug candidates suggests significant experience is required to optimize the operating time required for the procedure.
Collapse
Affiliation(s)
- Ioannis Christakis
- Division of Diabetes, Endocrinology & Metabolism, Department of Investigative Medicine, Imperial College London, London, United Kingdom
| | - Panagiotis Georgiou
- Department of Surgery, Chelsea and Westminster Hospital NHS Foundation Trust, Imperial College London, London, United Kingdom
| | - James Minnion
- Division of Diabetes, Endocrinology & Metabolism, Department of Investigative Medicine, Imperial College London, London, United Kingdom
| | - Vasilis Constantinides
- Department of Thyroid and Endocrine Surgery, Imperial College Healthcare NHS Trust, Hammersmith Campus, London, United Kingdom
| | - Joyceline Cuenco
- Division of Diabetes, Endocrinology & Metabolism, Department of Investigative Medicine, Imperial College London, London, United Kingdom
| | - Rebecca Scott
- Division of Diabetes, Endocrinology & Metabolism, Department of Investigative Medicine, Imperial College London, London, United Kingdom
| | - Tricia Tan
- Department of Endocrinology, Imperial College Healthcare NHS Trust, Imperial College London, London, United Kingdom
| | - Fausto Palazzo
- Department of Thyroid and Endocrine Surgery, Imperial College Healthcare NHS Trust, Imperial College London, London, United Kingdom
| | - Kevin Murphy
- Division of Diabetes, Endocrinology & Metabolism, Department of Investigative Medicine, Imperial College London, London, United Kingdom
| | - Stephen Bloom
- Division of Diabetes, Endocrinology & Metabolism, Department of Investigative Medicine, Imperial College London, London, United Kingdom.
| |
Collapse
|
23
|
van Kralingen S, Diepstraten J, Peeters MYM, Deneer VHM, van Ramshorst B, Wiezer RJ, van Dongen EPA, Danhof M, Knibbe CAJ. Population pharmacokinetics and pharmacodynamics of propofol in morbidly obese patients. Clin Pharmacokinet 2012; 50:739-50. [PMID: 21973271 DOI: 10.2165/11592890-000000000-00000] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND AND OBJECTIVES In view of the increasing prevalence of morbidly obese patients, the influence of excessive total bodyweight (TBW) on the pharmacokinetics and pharmacodynamics of propofol was characterized in this study using bispectral index (BIS) values as a pharmacodynamic endpoint. METHODS A population pharmacokinetic and pharmacodynamic model was developed with the nonlinear mixed-effects modelling software NONMEM VI, on the basis of 491 blood samples from 20 morbidly obese patients (TBW range 98-167 kg) and 725 blood samples from 44 lean patients (TBW range 55-98 kg) from previously published studies. In addition, 2246 BIS values from the 20 morbidly obese patients were available for pharmacodynamic analysis. RESULTS In a three-compartment pharmacokinetic model, TBW proved to be the most predictive covariate for clearance from the central compartment (CL) in the 20 morbidly obese patients (CL 2.33 L/min × [TBW/70]^[0.72]). Similar results were obtained when the morbidly obese patients and the 44 lean patients were analysed together (CL 2.22 L/min × [TBW/70]^[0.67]). No covariates were identified for other pharmacokinetic parameters. The depth of anaesthesia in the morbidly obese patients was adequately described by a two-compartment biophase-distribution model with a sigmoid maximum possible effect (E(max)) pharmacodynamic model (concentration at half-maximum effect [EC(50)] 2.12 mg/L) without covariates. CONCLUSION We developed a pharmacokinetic and pharmacodynamic model of propofol in morbidly obese patients, in which TBW proved to be the major determinant of clearance, using an allometric function with an exponent of 0.72. For the other pharmacokinetic and pharmacodynamic parameters, no covariates could be identified. Trial registration number (clinicaltrials.gov): NCT00395681.
Collapse
Affiliation(s)
- Simone van Kralingen
- Department of Anesthesiology and Intensive Care, St Antonius Hospital, Nieuwegein, the Netherlands
| | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Walsh VP, Gieseg M, Singh PM, Mitchinson SL, Chambers JP. A comparison of two different ketamine and diazepam combinations with an alphaxalone and medetomidine combination for induction of anaesthesia in sheep. N Z Vet J 2012; 60:136-41. [PMID: 22352931 DOI: 10.1080/00480169.2011.645769] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
AIMS To investigate the perceived adverse effects of a particular batch of ketamine during induction of anaesthesia in sheep and to assess if any adverse effects would make intubation more difficult for the veterinary students. METHODS Thirty adult sheep (mean bodyweight 74.5 (SD 9.4) kg) were randomly assigned to one of six groups of five sheep. Sheep in Groups A and B received I/V 0.5 mg/kg diazepam and 10 mg/kg ketamine (Ketamine Injection; Parnell Laboratories NZ Ltd, of the suspect batch); those in Groups C and D received I/V 0.5 mg/kg diazepam and 10 mg/kg ketamine (Ketalar; Hospira NZ Ltd.), and those in Groups E and F received I/V 2 μg/kg medetomidine and 2 mg/kg alphaxalone. In Groups A, C and E, intubation was by an experienced anaesthetist, and in Groups B, D and F intubation was by a veterinary student. Time from injection to successful intubation, the ease of intubation, saturation of haemoglobin with oxygen (SpO₂) and partial pressure of oxygen in arterial blood (PaO₂) were measured before the sheep were connected to an anaesthetic machine and allowed to breath oxygen. Times to extubation, holding its head up and standing, maximum and minimum heart rates, respiratory rates, maximal end tidal CO₂, and the quality of recovery were then recorded. RESULTS There were no measurable differences in outcomes between sheep in Groups A and B compared with C and D. Time to intubation was slightly shorter for the experienced anaesthetist than the student, but the difference was not significant. The sheep in Groups E and F took less time to recover than those in Groups A-D (p<0.05), but there were no significant differences between the groups in either the ease of induction or quality of recovery. Most sheep in Groups E and F showed minor excitatory effects, mainly at induction, which did not interfere with induction. Respiratory rates were lower in Groups E and F than Groups A-D (p<0.01), but SpO₂ was higher in Groups E and F than A and B (p<0.05). CONCLUSIONS The clinical impression that the batch of Parnell ketamine produced unexpected effects was shown to be incorrect. All the combinations produced anaesthesia that allowed intubation by the veterinary student. CLINICAL RELEVANCE All the drug combinations produced satisfactory anaesthesia in sheep, but the alphaxaloneand medetomidine combination resulted in faster recovery.
Collapse
Affiliation(s)
- V P Walsh
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand
| | | | | | | | | |
Collapse
|
25
|
Ambrisko TD, Johnson CB, Chambers P. Effect of alfaxalone infusion on the electroencephalogram of dogs anaesthetized with halothane. Vet Anaesth Analg 2011; 38:529-35. [PMID: 21988807 DOI: 10.1111/j.1467-2995.2011.00650.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To describe the effects of alfaxalone on the canine electroencephalogram (EEG). STUDY DESIGN Experimental study. ANIMALS Eight healthy adult Huntaway dogs. METHODS Anaesthesia was induced with propofol and maintained with halothane (0.85-0.95 end-tidal volume %) in oxygen. Animals were ventilated to maintain stable end-tidal CO(2) and halothane concentrations. Following a 30 minute stabilisation period, alfaxalone (0.5 mg kg(-1) ) was infused intravenously over a 5 minute period. The electroencephalogram was recorded from the beginning of the stabilisation period until 60 minutes following the start of alfaxalone treatment. Data were subjected to fast Fourier transformation, and median frequency, 95% spectral edge frequency and total EEG power were calculated. Two-factorial repeated measures anova (time and EEG channels were factors) was used for statistical analysis (p < 0.05). RESULTS A shift in the dominant frequency band from beta to delta after alfaxalone treatment and occasional burst suppression were observed. Median frequency decreased significantly below baseline (9.2 ± 1.4 Hz) (mean ± SD) during alfaxalone infusion. The lowest value (4.8 ± 1.2 Hz) was recorded 5 minutes after the start of infusion. Spectral edge frequency also decreased below baseline (26.2 ± 1.5 Hz) and the lowest value (22.6 ± 1.5 Hz) also was detected at 5 minutes after the start of infusion. Total EEG power did not change significantly. In some frequencies EEG power increased soon after the start of alfaxalone infusion, then decreased below baseline later (biphasic pattern). CONCLUSIONS AND CLINICAL RELEVANCE Alfaxalone induced biphasic changes on EEG and decreased F(50) and F(95) in halothane anaesthetized dogs.
Collapse
Affiliation(s)
- Tamas D Ambrisko
- Institute of Veterinary, Animal and Biomedical Sciences, College of Sciences, Massey University, Palmerston North, New Zealand.
| | | | | |
Collapse
|
26
|
Goodwin WA, Keates HL, Pasloske K, Pearson M, Sauer B, Ranasinghe MG. The pharmacokinetics and pharmacodynamics of the injectable anaesthetic alfaxalone in the horse. Vet Anaesth Analg 2011; 38:431-8. [DOI: 10.1111/j.1467-2995.2011.00634.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
27
|
Ellerkmann RK, Bruhn J, Soehle M, Kehrer M, Hoeft A, Kreuer S. Maximizing Prediction Probability P K as an Alternative Semiparametric Approach to Estimate the Plasma Effect-Site Equilibration Rate Constant k e 0. Anesth Analg 2009; 109:1470-8. [DOI: 10.1213/ane.0b013e3181b61efd] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
28
|
Ploeger BA, van der Graaf PH, Danhof M. Incorporating receptor theory in mechanism-based pharmacokinetic-pharmacodynamic (PK-PD) modeling. Drug Metab Pharmacokinet 2009; 24:3-15. [PMID: 19252332 DOI: 10.2133/dmpk.24.3] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pharmacokinetic-Pharmacodynamic (PK-PD) modeling helps to better understand drug efficacy and safety and has, therefore, become a powerful tool in the learning-confirming cycles of drug-development. In translational drug research, mechanism-based PK-PD modeling has been recognized as a tool for bringing forward early insights in drug efficacy and safety into the clinical development. These models differ from descriptive PK-PD models in that they quantitatively characterize specific processes in the causal chain between drug administration and effect. This includes target site distribution, binding and activation, pharmacodynamic interactions, transduction and homeostatic feedback mechanisms. Compared to descriptive models mechanism-based PK-PD models that utilize receptor theory concepts for characterization of target binding and target activation processes have improved properties for extrapolation and prediction. In this respect, receptor theory constitutes the basis for 1) prediction of in vivo drug concentration-effect relationships and 2) characterization of target association-dissociation kinetics as determinants of hysteresis in the time course of the drug effect. This approach intrinsically distinguishes drug- and system specific parameters explicitly, allowing accurate extrapolation from in vitro to in vivo and across species. This review provides an overview of recent developments in incorporating receptor theory in PK-PD modeling with a specific focus on the identifiability of these models.
Collapse
|
29
|
Sear JW. What makes a molecule an anaesthetic? Studies on the mechanisms of anaesthesia using a physicochemical approach. Br J Anaesth 2009; 103:50-60. [PMID: 19435782 DOI: 10.1093/bja/aep092] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Recent studies of mechanisms of anaesthesia have been mainly 'target orientated', investigating the activity of both volatile and i.v. agents at putative sites of action. An alternative approach is one that is 'ligand orientated', focusing on the properties of molecules that define their immobilizing ability and secondly define their potency. The use of conventional descriptors (such as non-polar solubility or the octanol-water partition coefficient [Log P]) are limited in their utility as predictors of potency as they represent three-dimensional molecular properties as a one-dimensional parameter. Using different computer-based molecular modelling methods (molecular similarity studies and comparative molecular field analysis [CoMFA]), we have identified the molecular bases of the activity of structurally diverse anaesthetics, such that they can be described as a single model based on the spatial distribution of molecular bulk and electrostatic potential. The same approach can also be used to model other properties of anaesthetic agents, such as cardiovascular depression. The present data suggest that, for the i.v. agents, it may be difficult to separate immobilizing (anaesthetic) activity and cardiovascular depression within a single molecule.
Collapse
Affiliation(s)
- J W Sear
- Nuffield Department of Anaesthetics, University of Oxford, John Radcliffe Hospital, Oxford, UK.
| |
Collapse
|
30
|
van Raay L, Morris MJ, Reed RC, O’Brien TJ, Dedeurwaerdere S. A novel system allowing long-term simultaneous video-electroencephalography recording, drug infusion and blood sampling in rats. J Neurosci Methods 2009; 179:184-90. [DOI: 10.1016/j.jneumeth.2009.01.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 01/23/2009] [Accepted: 01/26/2009] [Indexed: 10/21/2022]
|
31
|
Pharmacokinetic/pharmacodynamic modelling of the EEG effects of opioids: the role of complex biophase distribution kinetics. Eur J Pharm Sci 2008; 34:149-63. [PMID: 18467078 DOI: 10.1016/j.ejps.2008.03.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Revised: 03/10/2008] [Accepted: 03/22/2008] [Indexed: 01/16/2023]
Abstract
The objective of this investigation is to characterize the role of complex biophase distribution kinetics in the pharmacokinetic-pharmacodynamic correlation of a wide range of opioids. Following intravenous infusion of morphine, alfentanil, fentanyl, sufentanil, butorphanol and nalbuphine the time course of the EEG effect was determined in conjunction with blood concentrations. Different biophase distribution models were tested for their ability to describe hysteresis between blood concentration and effect. In addition, membrane transport characteristics of the opioids were investigated in vitro, using MDCK:MDR1 cells and in silico with QSAR analysis. For morphine, hysteresis was best described by an extended-catenary biophase distribution model with different values for k1e and keo of 0.038+/-0.003 and 0.043+/-0.003 min(-1), respectively. For the other opioids hysteresis was best described by a one-compartment biophase distribution model with identical values for k1e and keo. Between the different opioids, the values of k1e ranged from 0.04 to 0.47 min(-1). The correlation between concentration and EEG effect was successfully described by the sigmoidal Emax pharmacodynamic model. Between opioids significant differences in potency (EC50 range 1.2-451 ng/ml) and intrinsic activity (alpha range 18-109 microV) were observed. A statistically significant correlation was observed between the values of the in vivo k1e and the apparent passive permeability as determined in vitro in MDCK:MDR1 monolayers. It can be concluded that unlike other opioids, only morphine displays complex biophase distribution kinetics, which can be explained by its relatively low passive permeability and the interaction with active transporters at the blood-brain barrier.
Collapse
|
32
|
Danhof M, de Jongh J, De Lange ECM, Della Pasqua O, Ploeger BA, Voskuyl RA. Mechanism-Based Pharmacokinetic-Pharmacodynamic Modeling: Biophase Distribution, Receptor Theory, and Dynamical Systems Analysis. Annu Rev Pharmacol Toxicol 2007; 47:357-400. [PMID: 17067280 DOI: 10.1146/annurev.pharmtox.47.120505.105154] [Citation(s) in RCA: 203] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mechanism-based PK-PD models differ from conventional PK-PD models in that they contain specific expressions to characterize, in a quantitative manner, processes on the causal path between drug administration and effect. This includes target site distribution, target binding and activation, pharmacodynamic interactions, transduction, and homeostatic feedback mechanisms. As the final step, the effects on disease processes and disease progression are considered. Particularly through the incorporation of concepts from receptor theory and dynamical systems analysis, important progress has been made in the field of mechanism-based PK-PD modeling. This has yielded models with much-improved properties for extrapolation and prediction. These models constitute a theoretical basis for rational drug discovery and development.
Collapse
Affiliation(s)
- Meindert Danhof
- Leiden/Amsterdam Center for Drug Research, Division of Pharmacology, Leiden University, 2300 RA Leiden, The Netherlands.
| | | | | | | | | | | |
Collapse
|
33
|
Yassen A, Olofsen E, Kan J, Dahan A, Danhof M. Animal-to-Human Extrapolation of the Pharmacokinetic and Pharmacodynamic Properties of Buprenorphine. Clin Pharmacokinet 2007; 46:433-47. [PMID: 17465641 DOI: 10.2165/00003088-200746050-00005] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
OBJECTIVES This investigation describes the interspecies scaling of the pharmacokinetics and pharmacodynamics of buprenorphine. METHODS Data on the time course of the antinociceptive and respiratory depressant effects of buprenorphine in rats and in humans were simultaneously analysed on the basis of a mechanism-based pharmacokinetic-pharmacodynamic model. RESULTS An allometric three-compartment pharmacokinetic model described the time course of the concentration in plasma. The value of the allometric coefficient for clearance was 35.2 mL/min (relative standard error [RSE] = 5.6%) and the value of the allometric exponent was 0.76 (RSE 5.61%). A combined biophase distribution-receptor association/dissociation model with a linear transduction function described hysteresis between plasma concentration and effect. The values of the drug-specific pharmacodynamic parameters were identical in rats and in humans. For the respiratory depressant effect, the values of the second-order rate constant of receptor association (k(on)) and the first-order rate constant of receptor dissociation (k(off)) were 0.23 mL/ng/min (RSE = 15.8%) and 0.014 min(-1) (RSE = 27.7%), respectively, and the value of the equilibrium dissociation constant (K(diss)) was 0.13 nmol/L. The value of the intrinsic activity alpha was 0.52 (RSE = 3.4%). For the antinociceptive effect, the values of the k(on) and k(off) were 0.015 mL/ng/min (RSE = 18.3%) and 0.053 min(-1) (RSE = 23.1%), respectively. The value of the K(diss) was 7.5 nmol/L. An allometric equation described the scaling of the system-specific parameter, the first-order distribution rate constant (k(e0)). The value of the allometric coefficient for the k(e0) was 0.0303 min(-1) (RSE = 11.3%) and the value of the exponent was -0.28 (RSE = 9.6%). CONCLUSIONS The different values of the drug-specific pharmacodynamic parameters are consistent with the different opioid mu receptor subtypes involved in the antinociceptive and respiratory depressant effects.
Collapse
Affiliation(s)
- Ashraf Yassen
- Leiden/Amsterdam Center for Drug Research, Division of Pharmacology, Gorleaus Laboratories, Leiden, The Netherlands
| | | | | | | | | |
Collapse
|
34
|
Yassen A, Kan J, Olofsen E, Suidgeest E, Dahan A, Danhof M. Mechanism-based pharmacokinetic-pharmacodynamic modeling of the respiratory-depressant effect of buprenorphine and fentanyl in rats. J Pharmacol Exp Ther 2006; 319:682-92. [PMID: 16855177 DOI: 10.1124/jpet.106.107953] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The purpose of this investigation was to develop a mechanism-based pharmacokinetic/pharmacodynamic (PK/PD) model to predict the time course of respiratory depression following administration of opioids in rats. The proposed model is based on receptor theory and aims at the separate characterization of biophase distribution and receptor association/dissociation kinetics as determinants of hysteresis between plasma concentration and effect. Individual concentration time courses of buprenorphine and fentanyl were determined in conjunction with continuous monitoring of respiratory depression. Buprenorphine and fentanyl were administered intravenously in various doses. For buprenorphine hysteresis was best described by a combined biophase distribution-receptor association/dissociation model with a linear transducer function. The values of the parameter estimates of the rate constants for biophase distribution (k(eo)), receptor association (k(on)), and dissociation (k(off)) were 0.0348 min(-1) [95% confidence interval (CI), 0.0193-0.0503 min(-1)], 0.57 ml/ng/min (95% CI, 0.38-0.76 ml/ng/min), and 0.0903 min(-1) (95% CI, 0.035-0.196 min(-1)), respectively. The values of the equilibrium dissociation constant and intrinsic activity were 0.16 ng/ml and 0.48 (95% CI, 0.45-0.51), respectively. The value of the K(d) is close to reported estimates of receptor affinity in vitro confirming the validity of the mechanism-based PK/PD model. For fentanyl, unrealistically high estimates of the rate constants for receptor association and dissociation were obtained, indicating that hysteresis is caused solely by biophase distribution kinetics. This is consistent with fentanyl's fast receptor association/dissociation kinetics in vitro. As a result, the mechanism-based PK/PD model of fentanyl could be reduced to a biophase distribution model with fractional sigmoid E(max) pharmacodynamic model.
Collapse
Affiliation(s)
- Ashraf Yassen
- Leiden/Amsterdam Center for Drug Research, Division of Pharmacology, Gorlaeus Laboratories, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | | | | | | | | | | |
Collapse
|
35
|
Ferré PJ, Pasloske K, Whittem T, Ranasinghe MG, Li Q, Lefebvre HP. Plasma pharmacokinetics of alfaxalone in dogs after an intravenous bolus of Alfaxan-CD RTU. Vet Anaesth Analg 2006; 33:229-36. [PMID: 16764587 DOI: 10.1111/j.1467-2995.2005.00264.x] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To determine the pharmacokinetic parameters of alfaxalone in dogs after the intravenous (IV) administration of clinical and supra-clinical doses of a 2-hydroxypropyl-beta-cyclodextrin (HPCD) alfaxalone formulation (Alfaxan-CD RTU). EXPERIMENTAL DESIGN Prospective two-period crossover design. Animals Eight (four male and four female) young adult healthy Beagle dogs. Methods The steroid anaesthetic alfaxalone was administered IV at two doses in a crossover design (2 and 10 mg kg(-1)) with a washout period of 21 days. Blood samples were collected before and up to 8 hours after dosing. Plasma concentrations of alfaxalone were assayed using a liquid chromatograph/mass selective detector technique and analyzed to estimate the main pharmacokinetic parameters by noncompartmental analysis. Results were expressed as mean +/- SD. RESULTS The mean duration of anaesthesia from endotracheal intubation to extubation was 6.4 +/- 2.9 and 26.2 +/- 7.5 minutes, for the 2 and 10 mg kg(-1) doses, respectively. The plasma clearance of alfaxalone for the 2 and 10 mg kg(-1) doses differed statistically at 59.4 +/- 12.9 and 52.9 +/- 12.8 mL kg(-1) minute(-1), respectively (p = 0.008) but this difference was deemed clinically unimportant; the harmonic mean plasma terminal half-lives (t(1/2)) were 24.0 +/- 1.9 and 37.4 +/- 1.6 minutes respectively. The volume of distribution was between 2 and 3 L kg(-1) and did not differ between the two doses. No sex effect was observed. CONCLUSIONS AND CLINICAL RELEVANCE Alfaxalone, as an HPCD formulation (Alfaxan-CD RTU) administered in the dog provides rapid and smooth induction of anaesthesia, satisfactory conditions for endotracheal intubation and a short duration of anaesthesia. There was no clinically significant modification of the pharmacokinetic parameters between sexes and between the clinical (2 mg kg(-1)) and supra-clinical (10 mg kg(-1)) doses.
Collapse
Affiliation(s)
- Pierre J Ferré
- UMR 181 Physiopathologie et Toxicologie Expérimentales INRA-ENVT, France
| | | | | | | | | | | |
Collapse
|
36
|
Kiss T, Erdi P. From electric patterns to drugs: perspectives of computational neuroscience in drug design. Biosystems 2006; 86:46-52. [PMID: 16843588 DOI: 10.1016/j.biosystems.2006.02.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Revised: 02/13/2006] [Accepted: 02/15/2006] [Indexed: 11/29/2022]
Abstract
A novel way of computational modeling by integrating compartmental neural techniques and detailed kinetic description of pharmacological modulation of transmitter-receptor interaction is offered as a method to test the electro-physiological and behavioral effects of potential drugs. Even more, an inverse method is suggested as a method for controlling a neural system to realize a prescribed temporal pattern. Generation and pharamcological modulation of theta rhythm in area CA1 of the hippocampus related to anxiety is analyzed. Integrative modeling might help to find positive allosteric modulators of alpha1 subunits as potential candidates for being selective anxyolitics.
Collapse
Affiliation(s)
- Tamás Kiss
- Department of Biophysics, KFKI Research Institute for Particle and Nuclear Physics of the Hungarian Academy of Sciences, Budapest, Hungary
| | | |
Collapse
|
37
|
Post TM, Freijer JI, DeJongh J, Danhof M. Disease System Analysis: Basic Disease Progression Models in Degenerative Disease. Pharm Res 2005; 22:1038-49. [PMID: 16028004 DOI: 10.1007/s11095-005-5641-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2005] [Accepted: 04/26/2005] [Indexed: 10/25/2022]
Abstract
PURPOSE To describe the disease status of degenerative diseases (i.e., type 2 diabetes mellitus, Parkinson's disease) as function of disease process and treatment effects, a family of disease progression models is introduced. METHODS Disease progression is described using a progression rate (Rdp) acting on the synthesis or elimination parameters of the indirect response model. Symptomatic effects act as disease-dependent or -independent effects on the synthesis or elimination parameters. Protective drug effects act as disease dependent or -independent effects on Rdp. RESULTS Simulations with the ten disease models show distinctly different signature profiles of treatment effects on disease status. Symptomatic effects result in improvement of disease status with a subsequent deterioration. Treatment cessation results in a disease status equal to the situation where treatment had not been applied. Protective effects result in a lasting reduction, or even reversal, of the disease progression rate and the resulting disease status during the treatment period. After cessation of treatment the natural disease course will continue from the disease status at that point. CONCLUSION Disease system analysis constitutes a scientific basis for the distinction between symptomatic versus protective drug effects in relation to specific disease processes as well as the identification of the exposure-response relationship during the time-course of disease.
Collapse
Affiliation(s)
- Teun M Post
- Leiden Experts on Advanced Pharmacokinetics and Pharmacodynamics, Leiden, The Netherlands
| | | | | | | |
Collapse
|
38
|
Yassen A, Olofsen E, Dahan A, Danhof M. Pharmacokinetic-pharmacodynamic modeling of the antinociceptive effect of buprenorphine and fentanyl in rats: role of receptor equilibration kinetics. J Pharmacol Exp Ther 2005; 313:1136-49. [PMID: 15701707 DOI: 10.1124/jpet.104.082560] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The objective of this investigation was to characterize the pharmacokinetic/pharmacodynamic correlation of buprenorphine and fentanyl for the antinociceptive effect in rats. Data on the time course of the antinociceptive effect following intravenous administration of buprenorphine or fentanyl was analyzed in conjunction with plasma concentrations by nonlinear mixed-effects analysis. For fentanyl, the pharmacokinetics was described on the basis of a two-compartment pharmacokinetic model. For buprenorphine, a three-compartment pharmacokinetic model best described the concentration time course. To explain time dependencies in pharmacodynamics of buprenorphine and fentanyl, a combined effect compartment/receptor binding model was applied. A log logistic probability distribution model is proposed to account for censored tail-flick latencies. The model converged, yielding precise estimates of the parameters characterizing hysteresis. The results show that onset and offset of the antinociceptive effect of both buprenorphine and fentanyl is mainly determined by biophase distribution. The k(eo) was 0.024 min(-1) [95% confidence interval (CI): 0.018-0.030 min(-1)] and 0.123 min(-1) (95% CI: 0.095-0.151 min(-1)) for buprenorphine and fentanyl, respectively. On the other hand, part of the hysteresis in the buprenorphine pharmacodynamics could be explained by slow receptor association/dissociation kinetics. The k(off) was 0.073 min(-1) (95% CI: 0.042-0.104 min(-1)) and k(on) was 0.023 ml/ng/min (95% CI: 0.013-0.033 ml/ng/min). Fentanyl binds instantaneously to the OP3 receptor because no reasonable values for k(on) and k(off) were obtained with the dynamical receptor model. In contrast to earlier reports in the literature, the findings of this study show that the rate-limiting step in the onset and offset of buprenorphine's antinociceptive effect is distribution to the brain.
Collapse
Affiliation(s)
- Ashraf Yassen
- Leiden/Amsterdam Center for Drug Research, Division of Pharmacology, Gorlaeus Laboratories, The Netherlands
| | | | | | | |
Collapse
|
39
|
Bouwman BM, Heesen E, van Rijn CM. The interaction between vigabatrin and diazepam on the electroencephalogram during active behaviour in rats: an isobolic analysis. Eur J Pharmacol 2004; 495:119-28. [PMID: 15249160 DOI: 10.1016/j.ejphar.2004.05.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Accepted: 05/14/2004] [Indexed: 10/26/2022]
Abstract
To test whether polytherapy with two gamma-aminobutyric acid (GABA) -ergic drugs might be clinically relevant for epilepsy treatment, effects on spike and wave discharges, the fraction of time spent being behaviourally active, and the background electroencephalogram (EEG) during behavioural activity of vigabatrin (15-500 mg/kg i.p.) and diazepam (1.25-10 mg/kg i.p.) were compared with their combination (dose ratio 1:25) in rats. Isobolic analyses were performed to describe the interactions. Unfortunately, no conclusions can be drawn concerning the interaction of both drugs on the spike and wave discharge activity because the effect of diazepam was shown to be dominant. Only vigabatrin decreased the behavioural activity, whereas there was a trend towards a decrease after diazepam. All treatments dose dependently increased the power in the beta frequency band. Unfortunately, the dose ratio was not optimal to describe the interaction. The theta peak frequency was dose dependently decreased after all treatments. There was a synergistic interaction between the two drugs on this variable. These data support both the idea that an increase in power in the beta frequency band can serve as a biomarker for GABAergic inhibition and the suggestion that clinically effective anxiolytics decrease the theta peak frequency. Furthermore, we show that on different variables, there might be different optimal dosage combinations, which might complicate the clinical application of polytherapy.
Collapse
Affiliation(s)
- Brigitte M Bouwman
- NICI/Department of Biological Psychology, University of Nijmegen, P.O. Box 9104, 6500 HE Nijmegen, The Netherlands.
| | | | | |
Collapse
|
40
|
Sewell JC, Sear JW. Derivation of preliminary three-dimensional pharmacophoric maps for chemically diverse intravenous general anaesthetics † †This work was supported in part by a project grant from the British Journal of Anaesthesia. It was presented in part at the Anaesthetic Research Society meeting, Cardiff, July 2002 and published in abstract form in the Br J Anaesth 2002; 89: 672–673P. Br J Anaesth 2004; 92:45-53. [PMID: 14665552 DOI: 10.1093/bja/aeh016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The molecular basis of i.v. general anaesthetic activity was investigated using comparative molecular field analysis (CoMFA). METHODS The free plasma concentrations that abolish movement to a noxious stimulus for 14 structurally diverse i.v. anaesthetics were obtained from the literature. The compounds were randomly divided into a training set (n=10) to derive the activity model, and a separate test set (n=4) used to assess its predictive capability. The anaesthetic structures were aligned so as to maximize their similarities in molecular shape and electrostatic potential to conformers of the most active agent in the group, eltanolone. The conformers and alignments that showed the maximum similarity (calculated using combined Carbo indices) were retained, and used to derive the CoMFA models. RESULTS The final model explained 94.0% of the variance in the observed activities of the training set (n=10, P<0.0001) and was a good predictor of test set activity (n=4, r(2)=0.799). In contrast, a model based on non-polar solubility (LogP) explained only 78.3% of the variance in the observed activities of the training set (n=10, P=0.0007) and was a poor predictor for the test set (n=4, r(2)=0.272). Further analysis of the CoMFA results identified the spatial distribution of key areas where steric and electrostatic interactions are important in determining the activity of the 14 anaesthetics considered. CONCLUSIONS A single activity model can be formulated for i.v. general anaesthetics and preliminary pharmacophoric maps derived, which describe the molecular basis of their in vivo potency.
Collapse
Affiliation(s)
- J C Sewell
- Nuffield Department of Anaesthetics, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
| | | |
Collapse
|
41
|
Visser SAG, Huntjens DRH, van der Graaf PH, Peletier LA, Danhof M. Mechanism-based modeling of the pharmacodynamic interaction of alphaxalone and midazolam in rats. J Pharmacol Exp Ther 2003; 307:765-75. [PMID: 12975494 DOI: 10.1124/jpet.103.054510] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The objective of the present investigation was to characterize the pharmacodynamic interaction between the synthetic neuroactive steroid alphaxalone and the benzodiazepine midazolam. The time course of the electroencephalographic (EEG) effect (11.5-30 Hz) was determined in rats in conjunction with plasma concentrations. Alphaxalone was administered as a continuous intravenous infusion of 0, 1.2, 2.2, or 5.2 mg over 360 min. Midazolam was administered as a 5-min intravenous bolus infusion of 4 mg.kg-1. The pharmacokinetic profiles of both drugs were described by a two-compartment model. No pharmacokinetic interaction was observed. The EEG effect versus time profiles of midazolam and alphaxalone, when administered separately and in combination, were modeled on the basis of the recently proposed mechanism-based pharmacokinetic/pharmacodynamic model for GABAA receptor modulators, which contains separate expressions to describe the drug-receptor interaction and the stimulus-response relationship. The pharmacodynamic interaction between alphaxalone and midazolam was best characterized using an independent drug-drug interaction model without an expression for allosteric modulation of the effect of midazolam by alphaxalone. The final model contained an exponential expression to account for acute functional adaptation to the EEG effect upon continuous infusion of alphaxalone. The mechanism-based analysis showed that this functional adaptation is best explained by a change in the system-specific stimulus-response relationship, rather than the drug-receptor activation process. It is concluded that the pharmacodynamic interaction between alphaxalone and midazolam in vivo is best described using an independent interaction model without allosteric modulation.
Collapse
Affiliation(s)
- S A G Visser
- Division of Pharmacology, Leiden/Amsterdam Center for Drug Research, Leiden University, Einsteinweg 55, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | | | | | | | | |
Collapse
|
42
|
Jonker DM, Vermeij DAC, Edelbroek PM, Voskuyl RA, Piotrovsky VK, Danhof M. Pharmacodynamic analysis of the interaction between tiagabine and midazolam with an allosteric model that incorporates signal transduction. Epilepsia 2003; 44:329-38. [PMID: 12614388 DOI: 10.1046/j.1528-1157.2003.37802.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE The objective of this study was to characterize quantitatively the pharmacodynamic interaction between midazolam (MDL), an allosteric modulator of the gamma-aminobutyric acid subtype A (GABAA) receptor, and tiagabine (TGB), an inhibitor of synaptic GABA uptake. METHODS The in vivo concentration-response relation of TGB was determined through pharmacokinetic/pharmacodynamic (PK/PD) modeling. Rats received a single intravenous dose of 10 mg/kg TGB in the absence and the presence of a steady-state plasma concentration of MDL. The EEG response in the 11.5- to 30-Hz frequency band was used as the pharmacodynamic end point. RESULTS Infusion of MDL resulted in a mean steady-state plasma concentration of 66 +/- 3 ng/ml. A significant pharmacokinetic interaction with TGB was observed. MDL inhibited TGB clearance by 20 +/- 7 ml/min/kg from the original value of 89 +/- 6 ml/min/kg. However, no changes in plasma protein binding of both drugs were observed. The concentration-EEG relation of TGB was described by the sigmoid-Emax model. The pharmacodynamic parameter estimates of TGB were: Emax = 327 +/- 10 microV, EC50 = 392 +/- 20 ng/ml, and nH = 3.1 +/- 0.3. These values were not significantly different in the presence of MDL. Factors that may explain the lack of synergism were identified by a mechanism-based interaction model that separates the receptor activation from the signal-transduction process. High efficiency of signal transduction and the presence of a baseline response were shown to diminish the degree of synergism. CONCLUSIONS We conclude that the in vivo pharmacodynamic interaction between MDL and TGB is additive rather than synergistic. This strongly suggests that allosteric modulation of the antiseizure activity of a GAT-1 inhibitor by a benzodiazepine does not offer a therapeutic advantage.
Collapse
Affiliation(s)
- Daniël M Jonker
- Leiden/Amsterdam Center for Drug Research, Division of Pharmacology, Gorlaeus Laboratory, Leiden, The Netherlands
| | | | | | | | | | | |
Collapse
|
43
|
Visser SAG, Wolters FLC, van der Graaf PH, Peletier LA, Danhof M. Dose-dependent EEG effects of zolpidem provide evidence for GABA(A) receptor subtype selectivity in vivo. J Pharmacol Exp Ther 2003; 304:1251-7. [PMID: 12604703 DOI: 10.1124/jpet.102.044859] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Zolpidem is a nonbenzodiazepine GABA(A) receptor modulator that binds in vitro with high affinity to GABA(A) receptors expressing alpha(1) subunits but with relatively low affinity to receptors expressing alpha(2), alpha(3), and alpha(5) subunits. In the present study, it was investigated whether this subtype selectivity could be detected and quantified in vivo. Three doses (1.25, 5, and 25 mg) of zolpidem were administered to rats in an intravenous infusion over 5 min. The time course of the plasma concentrations was determined in conjunction with the change in the beta-frequency range of the EEG as pharmacodynamic endpoint. The concentration-effect relationship of the three doses showed a dose-dependent maximum effect and a dose-dependent potency. The data were analyzed for one- or two-site binding using two pharmacodynamic models based on 1) the descriptive model and 2) a novel mechanism-based pharmacokinetic/pharmacodynamic (PK/PD) model for GABA(A) receptor modulators that aims to separates drug- and system-specific properties, thereby allowing the estimation of in vivo affinity and efficacy. The application of two-site models significantly improved the fits compared with one-site models. Furthermore, in contrast to the descriptive model, the mechanism-based PK/PD model yielded dose-independent estimates for affinity (97 +/- 40 and 33,100 +/- 14,800 ng x ml(-1)). In conclusion, the mechanism-based PK/PD model is able to describe and explain the observed dose-dependent EEG effects of zolpidem and suggests the subtype selectivity of zolpidem in vivo.
Collapse
Affiliation(s)
- S A G Visser
- Division of Pharmacology, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, The Netherlands.
| | | | | | | | | |
Collapse
|
44
|
Visser SAG, Wolters FLC, Gubbens-Stibbe JM, Tukker E, Van Der Graaf PH, Peletier LA, Danhof M. Mechanism-based pharmacokinetic/pharmacodynamic modeling of the electroencephalogram effects of GABAA receptor modulators: in vitro-in vivo correlations. J Pharmacol Exp Ther 2003; 304:88-101. [PMID: 12490579 DOI: 10.1124/jpet.102.042341] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A mechanism-based pharmacokinetic-pharmacodynamic (PK/PD) model for neuroactive steroids, comprising a separate characterization of 1) the receptor activation process and 2) the stimulus-response relationship, was applied to various nonsteroidal GABAA receptor modulators. The EEG effects of nine prototypical GABAA receptor modulators (six benzodiazepines, one imidazopyridine, one cyclopyrrolone, and one beta-carboline) were determined in rats in conjunction with plasma concentrations. Population PK/PD modeling revealed monophasic concentration-EEG effect relationships with large differences in potency (EC50) and intrinsic activity between the compounds. The data were analyzed on the basis of the mechanism-based PK/PD model for (synthetic) neuroactive steroids on the assumption of a single and unique stimulus-response relationship. The model converged yielding estimates of both the apparent in vivo receptor affinity (KPD) and the in vivo intrinsic efficacy (ePD). The values of KPD ranged from 0.41 +/- 0 ng.ml(-1) for bretazenil to 436 +/- 72 ng.ml(-1) for clobazam and the values for e(PD) from -0.27 +/- 0 for methyl 6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate to 0.54 +/- 0.02 for diazepam. Significant linear correlations were observed between KPD for unbound concentrations and the affinity in an in vitro receptor bioassay (r = 0.93) and between e(PD) and the GABA-shift in vitro (r = 0.95). The findings of this investigation show that the in vivo effects of nonsteroidal GABAA receptor modulators and (synthetic) neuroactive steroids can be described on the basis of a single unique transducer function. In this paradigm, the nonsteroidal GABAA receptor modulators behave as partial agonists relative to neuroactive steroids.
Collapse
Affiliation(s)
- S A G Visser
- Division of Pharmacology, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
45
|
Visser SAG, Gladdines WWFT, van der Graaf PH, Peletier LA, Danhof M. Neuroactive steroids differ in potency but not in intrinsic efficacy at the GABA(A) receptor in vivo. J Pharmacol Exp Ther 2002; 303:616-26. [PMID: 12388643 DOI: 10.1124/jpet.102.039610] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The objective of the present investigation was to characterize the in vivo EEG effects of (synthetic) neuroactive steroids on the basis of a recently proposed mechanism-based pharmacokinetic/pharmacodynamic (PK/PD) model. After intravenous administration, the time course of the EEG effect of pregnanolone, 2beta-3alpha-5alpha-3-hydroxy-2-(2,2-dimethylmorpholin-4-yl)-pregnan-11,20-dione (ORG 21465), 2beta-3alpha-5alpha-21-chloro-3-hydroxy-2-(4-morpholinyl)-pregnan-20-one (ORG 20599), and alphaxalone was determined in conjunction with plasma concentrations in rats. For each neuroactive steroid the PK/PD correlation was described on the basis of a two-compartment pharmacokinetic model with an effect compartment to account for hysteresis. The observed concentration EEG effect relationships were biphasic and characterized with a mechanism-based pharmacodynamic model, which is based on a separation between the receptor activation process and the stimulus-response relationship. A single unique biphasic stimulus-response relationship could be identified for all neuroactive steroids, which was successfully described by a parabolic function. The receptor activation process was described by a hyperbolic function. Estimates for the maximum activation (e(PD)) were similar for the different neuroactive steroids but values of the potency estimate (K(PD)) ranged from 157 +/- 16 ng. ml(-1) for pregnanolone, 221 +/- 83 ng. ml(-1) for ORG 20599, and 483 +/- 42 ng. ml(-1) for alphaxalone to 1619 +/- 208 ng. ml(-1) for ORG 21465. A statistically significant correlation was observed between the in vivo potency and the IC(50) in an in vitro [(35)S]t-butylbicyclophosphorothionate binding assay (r = 0.91). It is concluded that the new PK/PD model constitutes a new mechanism-based approach to the quantification of the effects of (synthetic) neuroactive steroids in vivo effects. The results show that the neuroactive steroids differ in potency but not in intrinsic efficacy at the GABA(A) receptor in vivo.
Collapse
Affiliation(s)
- S A G Visser
- Division of Pharmacology, Leiden/Amsterdam Center for Drug Research, Leiden University, 2300 RA Leiden, The Netherlands
| | | | | | | | | |
Collapse
|