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Phillips KM, Rodriguez-Lopez JM, Webb AJ. Elevations in Norclobazam Concentrations and Altered Mental Status in CYP2C19 Poor Metabolizer Phenotype: A Case Report. Neurohospitalist 2023; 13:434-437. [PMID: 37701253 PMCID: PMC10494815 DOI: 10.1177/19418744231189078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023] Open
Abstract
Clobazam is a 1,5-benzodiazepine frequently used as an adjunctive agent for refractory seizures and status epilepticus. Clobazam undergoes metabolism to an active metabolite norclobazam which is subsequently hydroxylated by CYP2C19, a cytochrome with several pharmacogenetic variants. Patients with poor metabolizer phenotypes may have elevated norclobazam levels and subsequent adverse effects. We present a case of an Asian American male receiving clobazam at a standard therapeutic dose for seizure disorder who became comatose secondary to significantly elevated norclobazam concentrations. Genetic testing revealed the patient was a poor CYP2C19 metabolizer, accounting for the impaired clearance. Clinicians should be aware of the patient populations at risk for these genetic polymorphisms and adjust initial doses based on package labeling or consider therapeutic drug monitoring to avoid adverse effects.
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Affiliation(s)
| | - Josanna M. Rodriguez-Lopez
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Andrew J. Webb
- Department of Pharmacy, Massachusetts General Hospital, Boston, MA, USA
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2
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Ghosn NJ, Xie K, Pattnaik AR, Gugger JJ, Ellis CA, Sweeney E, Fox E, Bernabei JM, Johnson J, Boccanfuso J, Litt B, Conrad EC. A pharmacokinetic model of antiseizure medication load to guide care in the epilepsy monitoring unit. Epilepsia 2023; 64:1236-1247. [PMID: 36815252 PMCID: PMC10424095 DOI: 10.1111/epi.17558] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/21/2023] [Accepted: 02/21/2023] [Indexed: 02/24/2023]
Abstract
OBJECTIVE Evaluating patients with drug-resistant epilepsy often requires inducing seizures by tapering antiseizure medications (ASMs) in the epilepsy monitoring unit (EMU). The relationship between ASM taper strategy, seizure timing, and severity remains unclear. In this study, we developed and validated a pharmacokinetic model of total ASM load and tested its association with seizure occurrence and severity in the EMU. METHODS We studied 80 patients who underwent intracranial electroencephalographic recording for epilepsy surgery planning. We developed a first order pharmacokinetic model of the ASMs administered in the EMU to generate a continuous metric of overall ASM load. We then related modeled ASM load to seizure likelihood and severity. We determined the association between the rate of ASM load reduction, the length of hospital stay, and the probability of having a severe seizure. Finally, we used modeled ASM load to predict oncoming seizures. RESULTS Seizures occurred in the bottom 50th percentile of sampled ASM loads across the cohort (p < .0001, Wilcoxon signed-rank test), and seizures requiring rescue therapy occurred at lower ASM loads than seizures that did not require rescue therapy (logistic regression mixed effects model, odds ratio = .27, p = .01). Greater ASM decrease early in the EMU was not associated with an increased likelihood of having a severe seizure, nor with a shorter length of stay. SIGNIFICANCE A pharmacokinetic model can accurately estimate ASM levels for patients in the EMU. Lower modeled ASM levels are associated with increased seizure likelihood and seizure severity. We show that ASM load, rather than ASM taper speed, is associated with severe seizures. ASM modeling has the potential to help optimize taper strategy to minimize severe seizures while maximizing diagnostic yield.
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Affiliation(s)
- Nina J. Ghosn
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kevin Xie
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Akash R. Pattnaik
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - James J. Gugger
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Colin A. Ellis
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Elizabeth Sweeney
- Penn Statistics in Imaging and Visualization Endeavor Center, Department of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Emily Fox
- Department of Statistics, Stanford University, Stanford, California, USA
- Department of Computer Science, Stanford University, Stanford, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
| | - John M. Bernabei
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jenaye Johnson
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jacqueline Boccanfuso
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Brian Litt
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Erin C. Conrad
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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3
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Nabbout R, Chemaly N, Chiron C, Kuchenbuch M. Safety considerations selecting antiseizure medications for the treatment of individuals with Dravet syndrome. Expert Opin Drug Saf 2021; 20:561-576. [PMID: 33645379 DOI: 10.1080/14740338.2021.1890025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Introduction: Management of individuals with Dravet Syndrome has evolved significantly over the past 10 years. Progress has been made in understanding the pathophysiology, the long-term outcome and possible consequences of inappropriate therapies, new drugs have been approved by the regulatory authorities and patients and families expressed their needs beyond seizures' control.Areas covered: The authors aimed at providing an overview of the main antiseizure medications used in Dravet syndrome with a particular focus on safety considerations. As the highly active phase of seizures takes place before the age of 5 years, the characteristics of antiseizure medications in infancy and childhood have also been considered due to their impact on antiseizure medication safety.Expert opinion: Recent treatments, evaluated via randomized clinical trials, are promising in terms of efficacy and safety in individuals with DS. However, the balance between expected benefits and risks taken must be accurately assessed on an individual basis. There is a lack of data to understand the needs of patients and families, a major point particularly in this population, where the evaluation of efficacy and safety beyond seizures is difficult due to cognitive delay and behavioral disorders and where this evaluation is coming almost exclusively from caregivers.
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Affiliation(s)
- Rima Nabbout
- Reference Centre for Rare Epilepsies, Department of Pediatric Neurology, Necker Enfants Malades University Hospital, Université De Paris, Paris, France.,Institut National De La Santé Et De La Recherche Médicale (INSERM), UMR 1163, Institut Imagine, Université De Paris, Paris, France
| | - N Chemaly
- Reference Centre for Rare Epilepsies, Department of Pediatric Neurology, Necker Enfants Malades University Hospital, Université De Paris, Paris, France.,Institut National De La Santé Et De La Recherche Médicale (INSERM), UMR 1163, Institut Imagine, Université De Paris, Paris, France
| | - C Chiron
- Reference Centre for Rare Epilepsies, Department of Pediatric Neurology, Necker Enfants Malades University Hospital, Université De Paris, Paris, France.,INSERM U1141, Paris, France & Neurospin, CEA, Gif/Yvette, France
| | - M Kuchenbuch
- Reference Centre for Rare Epilepsies, Department of Pediatric Neurology, Necker Enfants Malades University Hospital, Université De Paris, Paris, France.,Institut National De La Santé Et De La Recherche Médicale (INSERM), UMR 1163, Institut Imagine, Université De Paris, Paris, France
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4
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Klomp SD, Manson ML, Guchelaar HJ, Swen JJ. Phenoconversion of Cytochrome P450 Metabolism: A Systematic Review. J Clin Med 2020; 9:jcm9092890. [PMID: 32906709 PMCID: PMC7565093 DOI: 10.3390/jcm9092890] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/03/2020] [Accepted: 09/04/2020] [Indexed: 12/15/2022] Open
Abstract
Phenoconversion is the mismatch between the individual’s genotype-based prediction of drug metabolism and the true capacity to metabolize drugs due to nongenetic factors. While the concept of phenoconversion has been described in narrative reviews, no systematic review is available. A systematic review was conducted to investigate factors contributing to phenoconversion and the impact on cytochrome P450 metabolism. Twenty-seven studies met the inclusion criteria and were incorporated in this review, of which 14 demonstrate phenoconversion for a specific genotype group. Phenoconversion into a lower metabolizer phenotype was reported for concomitant use of CYP450-inhibiting drugs, increasing age, cancer, and inflammation. Phenoconversion into a higher metabolizer phenotype was reported for concomitant use of CYP450 inducers and smoking. Moreover, alcohol, pregnancy, and vitamin D exposure are factors where study data suggested phenoconversion. The studies reported genotype–phenotype discrepancies, but the impact of phenoconversion on the effectiveness and toxicity in the clinical setting remains unclear. In conclusion, phenoconversion is caused by both extrinsic factors and patient- and disease-related factors. The mechanism(s) behind and the extent to which CYP450 metabolism is affected remain unexplored. If studied more comprehensively, accounting for phenoconversion may help to improve our ability to predict the individual CYP450 metabolism and personalize drug treatment.
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Affiliation(s)
- Sylvia D. Klomp
- Department of Clinical Pharmacy & Toxicology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; (S.D.K.); (H.-J.G.)
- Leiden Network for Personalised Therapeutics, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands;
| | - Martijn L. Manson
- Leiden Network for Personalised Therapeutics, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands;
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research (LACDR), Leiden University, 2333 CC Leiden, The Netherlands
| | - Henk-Jan Guchelaar
- Department of Clinical Pharmacy & Toxicology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; (S.D.K.); (H.-J.G.)
- Leiden Network for Personalised Therapeutics, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands;
| | - Jesse J. Swen
- Department of Clinical Pharmacy & Toxicology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; (S.D.K.); (H.-J.G.)
- Leiden Network for Personalised Therapeutics, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands;
- Correspondence:
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Hamilton KE, Shelton CM, Wheless J, Phelps SJ. Persistent Hypersomnolence Following Clobazam in a Child With Epilepsy and Undiagnosed CYP2C19 Polymorphism. J Pediatr Pharmacol Ther 2020; 25:320-327. [PMID: 32461746 DOI: 10.5863/1551-6776-25.4.320] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We describe an 11-year-old female who presented with severe hypersomnolence after receiving 1 week of modest doses of clobazam (CLB). In reviewing the above case, we considered that the hypersomnolence could be related to a pharmacodynamic, pharmacokinetic, or pharmacogenomic issue associated with CLB or to a combination of these factors. Although serum concentrations of CLB and its active metabolite are sensitive to factors that affect cytochrome-dependent metabolism, drug-drug interactions were omitted as a cause of the hypersomnolence. Subsequent DNA analysis of the cytochrome P450 2C19 gene revealed the patient as *2/*2 genotype with poor metabolizer enzyme activity. Because genetic testing of all patients treated with CLB is currently not practical, CLB dose/concentration ratios and pharmacokinetic drug-drug interaction impact models may be indicated. Genetic testing should be considered when an adverse effect suggests the possibility of a polymorphism important to drug metabolism.
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6
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Impact of CYP2C19 Phenotypes on Clinical Efficacy of Stiripentol in Japanese Patients With Dravet Syndrome. Ther Drug Monit 2020; 42:302-308. [DOI: 10.1097/ftd.0000000000000676] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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7
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Savage TE, Sourbron J, Bruno PL, Skirvin LA, Wolper ES, Anagnos CJ, Thiele EA. Efficacy of cannabidiol in subjects with refractory epilepsy relative to concomitant use of clobazam. Epilepsy Res 2020; 160:106263. [DOI: 10.1016/j.eplepsyres.2019.106263] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/23/2019] [Accepted: 12/27/2019] [Indexed: 10/25/2022]
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8
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Anderson LL, Absalom NL, Abelev SV, Low IK, Doohan PT, Martin LJ, Chebib M, McGregor IS, Arnold JC. Coadministered cannabidiol and clobazam: Preclinical evidence for both pharmacodynamic and pharmacokinetic interactions. Epilepsia 2019; 60:2224-2234. [PMID: 31625159 PMCID: PMC6900043 DOI: 10.1111/epi.16355] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/05/2019] [Accepted: 09/09/2019] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Cannabidiol (CBD) has been approved by the US Food and Drug Administration (FDA) to treat intractable childhood epilepsies, such as Dravet syndrome and Lennox-Gastaut syndrome. However, the intrinsic anticonvulsant activity of CBD has been questioned due to a pharmacokinetic interaction between CBD and a first-line medication, clobazam. This recognized interaction has led to speculation that the anticonvulsant efficacy of CBD may simply reflect CBD augmenting clobazam exposure. The present study aimed to address the nature of the interaction between CBD and clobazam. METHODS We examined whether CBD inhibits human CYP3A4 and CYP2C19 mediated metabolism of clobazam and N-desmethylclobazam (N-CLB), respectively, and performed studies assessing the effects of CBD on brain and plasma pharmacokinetics of clobazam in mice. We then used the Scn1a+/- mouse model of Dravet syndrome to examine how CBD and clobazam interact. We compared anticonvulsant effects of CBD-clobazam combination therapy to monotherapy against thermally-induced seizures, spontaneous seizures and mortality in Scn1a+/- mice. In addition, we used Xenopus oocytes expressing γ-aminobutyric acid (GABA)A receptors to investigate the activity of GABAA receptors when treated with CBD and clobazam together. RESULTS CBD potently inhibited CYP3A4 mediated metabolism of clobazam and CYP2C19 mediated metabolism of N-CLB. Combination CBD-clobazam treatment resulted in greater anticonvulsant efficacy in Scn1a+/- mice, but only when an anticonvulsant dose of CBD was used. It is important to note that a sub-anticonvulsant dose of CBD did not promote greater anticonvulsant effects despite increasing plasma clobazam concentrations. In addition, we delineated a novel pharmacodynamic mechanism where CBD and clobazam together enhanced inhibitory GABAA receptor activation. SIGNIFICANCE Our study highlights the involvement of both pharmacodynamic and pharmacokinetic interactions between CBD and clobazam that may contribute to its efficacy in Dravet syndrome.
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Affiliation(s)
- Lyndsey L. Anderson
- Brain and Mind CentreThe University of SydneySydneyNew South WalesAustralia
- Discipline of PharmacologyFaculty of Medicine and HealthThe University of SydneySydneyNew South WalesAustralia
- Lambert Initiative for Cannabinoid TherapeuticsThe University of SydneySydneyNew South WalesAustralia
| | - Nathan L. Absalom
- Lambert Initiative for Cannabinoid TherapeuticsThe University of SydneySydneyNew South WalesAustralia
- School of PharmacyFaculty of Medicine and HealthThe University of SydneySydneyNew South WalesAustralia
| | - Sarah V. Abelev
- Discipline of PharmacologyFaculty of Medicine and HealthThe University of SydneySydneyNew South WalesAustralia
| | - Ivan K. Low
- Lambert Initiative for Cannabinoid TherapeuticsThe University of SydneySydneyNew South WalesAustralia
| | - Peter T. Doohan
- Discipline of PharmacologyFaculty of Medicine and HealthThe University of SydneySydneyNew South WalesAustralia
| | - Lewis J. Martin
- Brain and Mind CentreThe University of SydneySydneyNew South WalesAustralia
- Lambert Initiative for Cannabinoid TherapeuticsThe University of SydneySydneyNew South WalesAustralia
| | - Mary Chebib
- Brain and Mind CentreThe University of SydneySydneyNew South WalesAustralia
- School of PharmacyFaculty of Medicine and HealthThe University of SydneySydneyNew South WalesAustralia
| | - Iain S. McGregor
- Brain and Mind CentreThe University of SydneySydneyNew South WalesAustralia
- Lambert Initiative for Cannabinoid TherapeuticsThe University of SydneySydneyNew South WalesAustralia
- School of PsychologyFaculty of ScienceThe University of SydneySydneyNew South WalesAustralia
| | - Jonathon C. Arnold
- Brain and Mind CentreThe University of SydneySydneyNew South WalesAustralia
- Discipline of PharmacologyFaculty of Medicine and HealthThe University of SydneySydneyNew South WalesAustralia
- Lambert Initiative for Cannabinoid TherapeuticsThe University of SydneySydneyNew South WalesAustralia
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9
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Klein P, Tolbert D, Gidal BE. Drug-drug interactions and pharmacodynamics of concomitant clobazam and cannabidiol or stiripentol in refractory seizures. Epilepsy Behav 2019; 99:106459. [PMID: 31519475 DOI: 10.1016/j.yebeh.2019.106459] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 07/22/2019] [Accepted: 07/26/2019] [Indexed: 02/08/2023]
Abstract
OBJECTIVE The goal of this study was to characterize the drug-drug interactions between clobazam and 2 antiseizure drugs, cannabidiol and stiripentol, for treatment of refractory seizures through the use of pharmacokinetic modeling. METHODS A population pharmacokinetic/pharmacodynamic model was developed to characterize the combined effect of clobazam and its active metabolite, N-desmethylclobazam (i.e., N-clobazam), on seizure protection in patients with Lennox-Gastaut syndrome using data from the phase 3 CONTAIN trial. Drug-drug interactions between clobazam and cannabidiol were examined by comparing model-generated data to data from a study of 13 patients taking concomitant clobazam and cannabidiol. Modeling data were also descriptively compared with studies of patients administered both clobazam and stiripentol. Sedation-related adverse events from CONTAIN were analyzed to determine the exposure-somnolence relationship of clobazam. RESULTS Exposure-efficacy analysis from the pharmacokinetic/pharmacodynamic model using CONTAIN data indicated that clobazam (half-maximal effective concentration [EC50], 303 ng/mL) was 3 times more potent than N-clobazam (EC50, 899 ng/mL). After administration of clobazam, when both clobazam and N-clobazam concentrations were each 1 to 2 times the EC50 value (clobazam dose, 20 mg), 70.0%-74.9% seizure protection was predicted; when concentrations were >2 times the EC50 value (clobazam dose, 40 mg), 74.0%-96.9% seizure protection was predicted. Generalized additive model analyses demonstrated decreased seizure probability with higher plasma concentration of clobazam. Coadministration of stiripentol and clobazam resulted in increased respective median plasma concentrations of clobazam and N-clobazam (1.1-1.2 times and 5.2-8.2 times) compared with administration of placebo and clobazam. Probability of somnolence significantly increased with age and higher N-clobazam plasma concentration. SIGNIFICANCE Awareness of drug-drug interactions between clobazam and cannabidiol is needed when adding cannabidiol or stiripentol to a regimen of clobazam or vice versa. Based upon our population pharmacokinetic/pharmacodynamic model, we predict that an increase in N-clobazam levels, which patient data show may enhance efficacy and/or make adverse events such as somnolence more likely.
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Affiliation(s)
- Pavel Klein
- Mid-Atlantic Epilepsy and Sleep Center, 6410 Rockledge Dr, Suite 610, Bethesda, MD 20817, USA.
| | - Dwain Tolbert
- Lundbeck, 6 Parkway North Suite 200, Deerfield, IL 60015, USA.
| | - Barry E Gidal
- School of Pharmacy, University of Wisconsin, 777 Highland Ave, Madison, WI 53705, USA.
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10
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Huddart R, Leeder JS, Altman RB, Klein TE. PharmGKB summary: clobazam pathway, pharmacokinetics. Pharmacogenet Genomics 2018; 28:110-115. [PMID: 29517622 PMCID: PMC5914180 DOI: 10.1097/fpc.0000000000000327] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
| | - J Steven Leeder
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Hospital, Kansas City, Missouri, USA
| | - Russ B Altman
- Biomedical Engineering
- Genetics, Stanford University, Stanford, California
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11
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Therapeutic Drug Monitoring of Clobazam and Its Metabolite-Impact of Age and Comedication on Pharmacokinetic Variability. Ther Drug Monit 2017; 38:350-7. [PMID: 26751267 DOI: 10.1097/ftd.0000000000000272] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Clobazam (CLB) has been used as an antiepileptic drug for several decades. There is still insufficient data regarding its pharmacokinetic variability in clinical practice. The purpose of this study was to investigate pharmacokinetic variability of CLB with emphasis on the impact of age and comedication in patients with epilepsy. METHODS Serum concentration measurements of CLB and its metabolite N-desmethylclobazam (NCLB), as well as demographic and clinical data were retrieved from the routine therapeutic drug monitoring service at the National Center for Epilepsy, Norway, 2009-2013. NCLB/CLB and total (CLB + NCLB), CLB and NCLB concentration/dose (C/D) ratios were calculated. RESULTS 550 patients (296 women/254 men), average age 27 years (range 1-86), were included. The interindividual pharmacokinetic variability was extensive, as illustrated by a 100-fold variability in serum concentration compared with dose (total C/D ratio 0.03-3.29 µmol·L·mg). The CLB C/D ratio was 36% lower in young children (2-9 years) than in adults (18-64 years), reflecting a higher clearance. In patients receiving phenytoin, felbamate, stiripentol, oxcarbazepine or eslicarbazepine acetate, valproate, phenobarbital, zonisamide or carbamazepine one or more of the calculated ratios were significantly different from that in patients receiving no or neutral comedications. The mean values for the different groups were in the order of 20%-230% of C/D ratios in the neutral group and 200%-950% of the NCLB/CLB ratio. CONCLUSIONS The pharmacokinetic variability of CLB and its metabolite NCLB in clinical practice is extensive, and is influenced by drug-drug interactions, age, and pharmacogenetics. Therapeutic drug monitoring of CLB and NCLB is therefore valuable in patient management.
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12
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Bahar MA, Setiawan D, Hak E, Wilffert B. Pharmacogenetics of drug-drug interaction and drug-drug-gene interaction: a systematic review on CYP2C9, CYP2C19 and CYP2D6. Pharmacogenomics 2017; 18:701-739. [PMID: 28480783 DOI: 10.2217/pgs-2017-0194] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Currently, most guidelines on drug-drug interaction (DDI) neither consider the potential effect of genetic polymorphism in the strength of the interaction nor do they account for the complex interaction caused by the combination of DDI and drug-gene interaction (DGI) where there are multiple biotransformation pathways, which is referred to as drug-drug-gene interaction (DDGI). In this systematic review, we report the impact of pharmacogenetics on DDI and DDGI in which three major drug-metabolizing enzymes - CYP2C9, CYP2C19 and CYP2D6 - are central. We observed that several DDI and DDGI are highly gene-dependent, leading to a different magnitude of interaction. Precision drug therapy should take pharmacogenetics into account when drug interactions in clinical practice are expected.
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Affiliation(s)
- Muh Akbar Bahar
- Department of PharmacoTherapy, Epidemiology & Economics, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands.,Faculty of Pharmacy, Hasanuddin University, Makassar, Indonesia
| | - Didik Setiawan
- Department of PharmacoTherapy, Epidemiology & Economics, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands.,Faculty of Pharmacy, University of Muhammadiyah Purwokerto, Purwokerto, Indonesia
| | - Eelko Hak
- Department of PharmacoTherapy, Epidemiology & Economics, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands
| | - Bob Wilffert
- Department of PharmacoTherapy, Epidemiology & Economics, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands.,Department of Clinical Pharmacy & Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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Jogamoto T, Yamamoto Y, Fukuda M, Suzuki Y, Imai K, Takahashi Y, Inoue Y, Ohtsuka Y. Add-on stiripentol elevates serum valproate levels in patients with or without concomitant topiramate therapy. Epilepsy Res 2017; 130:7-12. [DOI: 10.1016/j.eplepsyres.2016.12.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 12/20/2016] [Accepted: 12/25/2016] [Indexed: 12/17/2022]
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14
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Huang W, Ji CM, Guo M, Ni WW, Meng L, Wei JF. Pharmacogenomics of proton pump inhibitors. Shijie Huaren Xiaohua Zazhi 2016; 24:4458-4466. [DOI: 10.11569/wcjd.v24.i33.4458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
At present, proton pump inhibitors (PPIs), as a class of strong antacid agents, are widely used in the clinical treatment of gastrointestinal diseases. PPIs achieved a strong effect of acid suppression with high specificity and long duration. However, the issue of PPI abuse exists worldwide because of the lack of relevant knowledge. Due to tremendous inter-individual differences in uptake, the clinical application of PPIs appears to be limited. Therefore, rational use of PPIs in daily clinical practice is an important research topic. In addition, PPIs were found with many side effects. CYP2C19, as one of the most important enzymes in cytochrome P450 enzyme family, is responsible for the metabolism of over 10% of drugs. The bioavailability and metabolism of PPIs are mainly affected by drug-metabolizing enzymes CYP2C19 and CYP3A4, which are located in the liver. By suppressing cytochrome P450 isoenzyme, PPIs may affect the metabolism of multiple drugs, thus leading to unwanted side effects in case of combined medication. What's more, the individual difference in PPI administration is derived from distinct molecular mechanisms mediated by CYP3A4 and/or CYP2C19. Non-genetic factors, such as combined medication and food pyramid, also impact on the effectiveness of PPIs. Gene mutations can also alter the enzymatic activity of CY2C19, thereby resulting in different blood concentrations of drugs metabolized by CYP2C19. In conclusion, PPIs have the advantages of safety and effectiveness; however, the problem of drug resistance still exists, which indicates their selective application in clinical practice. In this paper, we review the advances in pharmacogenomics of PPIs, with an aim to provide reference to individualized clinical medication.
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Abstract
INTRODUCTION Stiripentol and vigabatrin are the two anticonvulsant drugs currently approved in severe infantile-onset epilepsies, respectively Dravet syndrome and infantile spasms. AREAS COVERED For both, the indication was discovered by chance thanks to an exploratory study. Both demonstrated indisputable efficacy through randomized-controlled trials. Stiripentol as adjunctive therapy to clobazam and valproate performed better than placebo, and vigabatrin as first-line monotherapy better than the reference steroid therapy in spasms due to tuberous sclerosis. At one-year treatment vigabatrin and steroids were equally efficient in the other etiologies of spasms. However, it took more than 20 years for both drugs to be approved world-wide. EXPERT OPINION Stiripentol suffered from pharmacokinetic potentiation of clobazam, thus raising the question whether it was efficient per se. Finally, animal models and pharmacogenetic data on CYP2C19 confirmed its specific anticonvulsant effect. Stiripentol (in comedication with clobazam and valproate) is therefore to be recommended for Dravet patients. Vigabatrin was found to have a frequent and irreversible retinal toxicity, which required an alternative visual testing to be detected in young children. Today the benefit/risk ratio of vigabatrin as first-line is considered to be positive in infantile spasms, given the severity of this epilepsy and the lack of a safer alternative therapy.
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Affiliation(s)
- Catherine Chiron
- a INSERM U1129, Neuropediatric Department , Necker Enfants-Malades Hospital , Paris , France
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16
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Devinsky O, Marsh E, Friedman D, Thiele E, Laux L, Sullivan J, Miller I, Flamini R, Wilfong A, Filloux F, Wong M, Tilton N, Bruno P, Bluvstein J, Hedlund J, Kamens R, Maclean J, Nangia S, Singhal NS, Wilson CA, Patel A, Cilio MR. Cannabidiol in patients with treatment-resistant epilepsy: an open-label interventional trial. Lancet Neurol 2015; 15:270-8. [PMID: 26724101 DOI: 10.1016/s1474-4422(15)00379-8] [Citation(s) in RCA: 598] [Impact Index Per Article: 66.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 11/09/2015] [Accepted: 11/26/2015] [Indexed: 10/22/2022]
Abstract
BACKGROUND Almost a third of patients with epilepsy have a treatment-resistant form, which is associated with severe morbidity and increased mortality. Cannabis-based treatments for epilepsy have generated much interest, but scientific data are scarce. We aimed to establish whether addition of cannabidiol to existing anti-epileptic regimens would be safe, tolerated, and efficacious in children and young adults with treatment-resistant epilepsy. METHODS In this open-label trial, patients (aged 1-30 years) with severe, intractable, childhood-onset, treatment-resistant epilepsy, who were receiving stable doses of antiepileptic drugs before study entry, were enrolled in an expanded-access programme at 11 epilepsy centres across the USA. Patients were given oral cannabidiol at 2-5 mg/kg per day, up-titrated until intolerance or to a maximum dose of 25 mg/kg or 50 mg/kg per day (dependent on study site). The primary objective was to establish the safety and tolerability of cannabidiol and the primary efficacy endpoint was median percentage change in the mean monthly frequency of motor seizures at 12 weeks. The efficacy analysis was by modified intention to treat. Comparisons of the percentage change in frequency of motor seizures were done with a Mann-Whitney U test. RESULTS Between Jan 15, 2014, and Jan 15, 2015, 214 patients were enrolled; 162 (76%) patients who had at least 12 weeks of follow-up after the first dose of cannabidiol were included in the safety and tolerability analysis, and 137 (64%) patients were included in the efficacy analysis. In the safety group, 33 (20%) patients had Dravet syndrome and 31 (19%) patients had Lennox-Gastaut syndrome. The remaining patients had intractable epilepsies of different causes and type. Adverse events were reported in 128 (79%) of the 162 patients within the safety group. Adverse events reported in more than 10% of patients were somnolence (n=41 [25%]), decreased appetite (n=31 [19%]), diarrhoea (n=31 [19%]), fatigue (n=21 [13%]), and convulsion (n=18 [11%]). Five (3%) patients discontinued treatment because of an adverse event. Serious adverse events were reported in 48 (30%) patients, including one death-a sudden unexpected death in epilepsy regarded as unrelated to study drug. 20 (12%) patients had severe adverse events possibly related to cannabidiol use, the most common of which was status epilepticus (n=9 [6%]). The median monthly frequency of motor seizures was 30.0 (IQR 11.0-96.0) at baseline and 15.8 (5.6-57.6) over the 12 week treatment period. The median reduction in monthly motor seizures was 36.5% (IQR 0-64.7). INTERPRETATION Our findings suggest that cannabidiol might reduce seizure frequency and might have an adequate safety profile in children and young adults with highly treatment-resistant epilepsy. Randomised controlled trials are warranted to characterise the safety profile and true efficacy of this compound. FUNDING GW Pharmaceuticals, Epilepsy Therapy Project of the Epilepsy Foundation, Finding A Cure for Epilepsy and Seizures.
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Affiliation(s)
- Orrin Devinsky
- Comprehensive Epilepsy Center, New York University Langone Medical Center, New York, NY, USA.
| | - Eric Marsh
- Departments of Neurology and Pediatrics, Division of Child Neurology, Children's Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Daniel Friedman
- Comprehensive Epilepsy Center, New York University Langone Medical Center, New York, NY, USA
| | | | - Linda Laux
- Ann & Robert H Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Joseph Sullivan
- Departments of Neurology and Pediatrics, Benioff Children's Hospital, University of California, San Francisco, San Francisco, CA, USA
| | - Ian Miller
- Miami Children's Hospital, Miami, FL, USA
| | - Robert Flamini
- Pediatric and Adolescent Neurodevelopmental Associates, Atlanta, GA, USA
| | | | - Francis Filloux
- University of Utah Medical Center and Primary Children's Hospital, Salt Lake City, UT, USA
| | - Matthew Wong
- Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Nicole Tilton
- Departments of Neurology and Pediatrics, Benioff Children's Hospital, University of California, San Francisco, San Francisco, CA, USA
| | - Patricia Bruno
- Massachusettes General Hospital for Children, Boston, MA, USA
| | - Judith Bluvstein
- Comprehensive Epilepsy Center, New York University Langone Medical Center, New York, NY, USA
| | - Julie Hedlund
- Comprehensive Epilepsy Center, New York University Langone Medical Center, New York, NY, USA
| | - Rebecca Kamens
- Departments of Neurology and Pediatrics, Division of Child Neurology, Children's Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Jane Maclean
- Departments of Neurology and Pediatrics, Division of Child Neurology, Children's Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Srishti Nangia
- Ann & Robert H Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Nilika Shah Singhal
- Departments of Neurology and Pediatrics, Benioff Children's Hospital, University of California, San Francisco, San Francisco, CA, USA
| | - Carey A Wilson
- University of Utah Medical Center and Primary Children's Hospital, Salt Lake City, UT, USA
| | - Anup Patel
- Nationwide Children's Hospital, Columbus, OH, USA
| | - Maria Roberta Cilio
- Departments of Neurology and Pediatrics, Benioff Children's Hospital, University of California, San Francisco, San Francisco, CA, USA
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Pharmacokinetics of Clobazam and N-Desmethylclobazam in Children with Dravet Syndrome Receiving Concomitant Stiripentol and Valproic Acid. Clin Pharmacokinet 2014; 54:527-36. [DOI: 10.1007/s40262-014-0223-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Huang X, Guo Y, Huang WH, Zhang W, Tan ZR, Peng JB, Wang YC, Hu DL, Ouyang DS, Xiao J, Wang Y, Luo M, Chen Y. Searching the cytochrome p450 enzymes for the metabolism of meranzin hydrate: a prospective antidepressant originating from Chaihu-Shugan-San. PLoS One 2014; 9:e113819. [PMID: 25427198 PMCID: PMC4245237 DOI: 10.1371/journal.pone.0113819] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 10/30/2014] [Indexed: 11/19/2022] Open
Abstract
Meranzin hydrate (MH), an absorbed bioactive compound from the Traditional Chinese Medicine (TCM) Chaihu-Shugan-San (CSS), was first isolated in our laboratory and was found to possess anti-depression activity. However, the role of cytochrome P450s (CYPs) in the metabolism of MH was unclear. In this study, we screened the CYPs for the metabolism of MH in vitro by human liver microsomes (HLMs) or human recombinant CYPs. MH inhibited the enzyme activities of CYP1A2 and CYP2C19 in a concentration-dependent manner in the HLMs. The Km and Vmax values of MH were 10.3±1.3 µM and 99.1±3.3 nmol/mg protein/min, respectively, for the HLMs; 8.0±1.6 µM and 112.4±5.7 nmol/nmol P450/min, respectively, for CYP1A2; and 25.9±6.6 µM and 134.3±12.4 nmol/nmol P450/min, respectively, for CYP2C19. Other human CYP isoforms including CYP2A6, CYP2C9, CYP2D6, CYP2E1 and CYP3A4 showed minimal or no effect on MH metabolism. The results suggested that MH was simultaneously a substrate and an inhibitor of CYP1A2 and CYP2C9, and MH had the potential to perpetrate drug-drug interactions with other CYP1A2 and CYP2C19 substrates.
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Affiliation(s)
- Xi Huang
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, Hunan 410078, China
- Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, 110 Xiangya road, Changsha, Hunan 410078, China
- Laboratory of Ethnopharmacology, Institute of Integrated Traditional Chinese and Western Medicine, Xiangya Hospital, Central South University, 87 Xiangya Road, 410008 Changsha, China
| | - Ying Guo
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, Hunan 410078, China
- Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, 110 Xiangya road, Changsha, Hunan 410078, China
| | - Wei-hua Huang
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, Hunan 410078, China
- Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, 110 Xiangya road, Changsha, Hunan 410078, China
| | - Wei Zhang
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, Hunan 410078, China
- Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, 110 Xiangya road, Changsha, Hunan 410078, China
| | - Zhi-rong Tan
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, Hunan 410078, China
- Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, 110 Xiangya road, Changsha, Hunan 410078, China
| | - Jing-bo Peng
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, Hunan 410078, China
- Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, 110 Xiangya road, Changsha, Hunan 410078, China
| | - Yi-cheng Wang
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, Hunan 410078, China
- Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, 110 Xiangya road, Changsha, Hunan 410078, China
| | - Dong-li Hu
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, Hunan 410078, China
- Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, 110 Xiangya road, Changsha, Hunan 410078, China
| | - Dong-sheng Ouyang
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, Hunan 410078, China
- Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, 110 Xiangya road, Changsha, Hunan 410078, China
| | - Jian Xiao
- Laboratory of Ethnopharmacology, Institute of Integrated Traditional Chinese and Western Medicine, Xiangya Hospital, Central South University, 87 Xiangya Road, 410008 Changsha, China
| | - Yang Wang
- Laboratory of Ethnopharmacology, Institute of Integrated Traditional Chinese and Western Medicine, Xiangya Hospital, Central South University, 87 Xiangya Road, 410008 Changsha, China
| | - Min Luo
- Laboratory of Ethnopharmacology, Institute of Integrated Traditional Chinese and Western Medicine, Xiangya Hospital, Central South University, 87 Xiangya Road, 410008 Changsha, China
| | - Yao Chen
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, Hunan 410078, China
- Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, 110 Xiangya road, Changsha, Hunan 410078, China
- Laboratory of Ethnopharmacology, Institute of Integrated Traditional Chinese and Western Medicine, Xiangya Hospital, Central South University, 87 Xiangya Road, 410008 Changsha, China
- * E-mail:
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Impact of cytochrome P450 inducers with or without inhibitors on the serum clobazam level in patients with antiepileptic polypharmacy. Eur J Clin Pharmacol 2014; 70:1203-10. [DOI: 10.1007/s00228-014-1719-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 07/08/2014] [Indexed: 10/25/2022]
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Krasowski MD, McMillin GA. Advances in anti-epileptic drug testing. Clin Chim Acta 2014; 436:224-36. [PMID: 24925169 DOI: 10.1016/j.cca.2014.06.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 05/29/2014] [Accepted: 06/03/2014] [Indexed: 12/12/2022]
Abstract
In the past twenty-one years, 17 new antiepileptic drugs have been approved for use in the United States and/or Europe. These drugs are clobazam, ezogabine (retigabine), eslicarbazepine acetate, felbamate, gabapentin, lacosamide, lamotrigine, levetiracetam, oxcarbazepine, perampanel, pregabalin, rufinamide, stiripentol, tiagabine, topiramate, vigabatrin and zonisamide. Therapeutic drug monitoring is often used in the clinical dosing of the newer anti-epileptic drugs. The drugs with the best justifications for drug monitoring are lamotrigine, levetiracetam, oxcarbazepine, stiripentol, and zonisamide. Perampanel, stiripentol and tiagabine are strongly bound to serum proteins and are candidates for monitoring of the free drug fractions. Alternative specimens for therapeutic drug monitoring are saliva and dried blood spots. Therapeutic drug monitoring of the new antiepileptic drugs is discussed here for managing patients with epilepsy.
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Affiliation(s)
- Matthew D Krasowski
- Department of Pathology, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, United States.
| | - Gwendolyn A McMillin
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, United States; ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories Inc., Salt Lake City, UT, United States
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Yamamoto Y, Takahashi Y, Imai K, Mogami Y, Matsuda K, Nakai M, Kagawa Y, Inoue Y. Interaction between sulthiame and clobazam: sulthiame inhibits the metabolism of clobazam, possibly via an action on CYP2C19. Epilepsy Behav 2014; 34:124-6. [PMID: 24742983 DOI: 10.1016/j.yebeh.2014.03.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 03/21/2014] [Accepted: 03/23/2014] [Indexed: 11/29/2022]
Abstract
The aim of this study was to investigate the effect of sulthiame (STM) on the pharmacokinetics of clobazam (CLB) by determining the concentration to dose (CD) ratio (serum level (ng/ml) divided by dose (mg/kg)) of CLB and that of N-desmethyl-clobazam (DMCLB). We evaluated five patients (an adult and four children) whose serum CLB and DMCLB concentrations were monitored after the addition or discontinuation of STM. Four of the five patients were CYP2C19 intermediate metabolizers, and one patient was an extensive metabolizer. When the patients were taking STM (100-275 mg/day), the mean CD ratio of DMCLB increased by 82.6 to 248.5%, which was higher than when they were not using STM. The increase was dose-dependent. In contrast, the CD ratio of CLB remained stable after addition or discontinuation of STM. These data suggest that STM has the potential to inhibit CYP2C19 enzyme activity. During combination therapy with STM and CLB in patients with CYP2C19 intermediate or extensive metabolizer phenotypes, monitoring of DMCLB concentrations may be helpful in ascertaining CLB-related adverse effects.
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Affiliation(s)
- Yoshiaki Yamamoto
- Department of Clinical Research, National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, 886 Urushiyama, Shizuoka 420-8688, Japan; Department of Clinical Pharmaceutics, Graduate School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan.
| | - Yukitoshi Takahashi
- Department of Clinical Research, National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, 886 Urushiyama, Shizuoka 420-8688, Japan
| | - Katsumi Imai
- Department of Clinical Research, National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, 886 Urushiyama, Shizuoka 420-8688, Japan
| | - Yukiko Mogami
- Department of Clinical Research, National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, 886 Urushiyama, Shizuoka 420-8688, Japan
| | - Kazumi Matsuda
- Department of Clinical Research, National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, 886 Urushiyama, Shizuoka 420-8688, Japan
| | - Masahiko Nakai
- Department of Clinical Research, National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, 886 Urushiyama, Shizuoka 420-8688, Japan
| | - Yoshiyuki Kagawa
- Department of Clinical Pharmaceutics, Graduate School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan; Laboratory of Clinical Pharmacokinetics and Drug Safety, Shizuoka General Hospital, 4-27-1 Kita Ando, Shizuoka 420-8527, Japan
| | - Yushi Inoue
- Department of Clinical Research, National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, 886 Urushiyama, Shizuoka 420-8688, Japan
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22
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Jensen HS, Nichol K, Lee D, Ebert B. Clobazam and its active metabolite N-desmethylclobazam display significantly greater affinities for α₂- versus α₁-GABA(A)-receptor complexes. PLoS One 2014; 9:e88456. [PMID: 24533090 PMCID: PMC3922815 DOI: 10.1371/journal.pone.0088456] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 01/07/2014] [Indexed: 01/09/2023] Open
Abstract
Clobazam (CLB), a 1,5-benzodiazepine (BZD), was FDA-approved in October 2011 for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients 2 years and older. BZDs exert various CNS effects through allosteric modulation of GABAA receptors. The structurally distinct, 1,4-BZD clonazepam (CLN) is also approved to treat LGS. The precise mechanisms of action and clinical efficacy of both are unknown. Data show that the GABAA α1-subunit–selective compound zolpidem [ZOL] exhibits hypnotic/sedative effects. Conversely, data from knock-in mice carrying BZD binding site mutations suggest that the α2 subunit mediates anticonvulsant effects, without sedative actions. Hence, the specific pattern of interactions across the GABAA receptor complexes of BZDs might be reflected in their clinical efficacies and adverse effect profiles. In this study, GABAA-receptor binding affinities of CLB, N-desmethylclobazam (N-CLB, the major metabolite of CLB), CLN, and ZOL were characterized with native receptors from rat-brain homogenates and on cloned receptors from HEK293 cells transfected with combinations of α (α1, α2, α3, or α5), β2, and γ2 subtypes. Our results demonstrate that CLB and N-CLB have significantly greater binding affinities for α2- vs. α1-receptor complexes, a difference not observed for CLN, for which no distinction between α2 and α1 receptors was observed. Our experiments with ZOL confirmed the high preference for α1 receptors. These results provide potential clues to a new understanding of the pharmacologic modes of action of CLB and N-CLB.
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Affiliation(s)
- Henrik Sindal Jensen
- Synaptic Transmission, Neuroscience Drug Discovery, H. Lundbeck A/S, Valby, Denmark
- * E-mail:
| | - Kathryn Nichol
- Medical Affairs, Lundbeck LLC, Deerfield, Illinois, United States of America
| | - Deborah Lee
- Clinical Affairs, Lundbeck LLC, Deerfield, Illinois, United States of America
| | - Bjarke Ebert
- Department of Electrophysiology, H. Lundbeck A/S, Valby, Denmark
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