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Pla-Tenorio J, Roig AM, García-Cesaní PA, Santiago LA, Sepulveda-Orengo MT, Noel RJ. Astrocytes: Role in pathogenesis and effect of commonly misused drugs in the HIV infected brain. CURRENT RESEARCH IN NEUROBIOLOGY 2023; 5:100108. [PMID: 38020814 PMCID: PMC10663134 DOI: 10.1016/j.crneur.2023.100108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 06/05/2023] [Accepted: 08/18/2023] [Indexed: 12/01/2023] Open
Abstract
The roles of astrocytes as reservoirs and producers of a subset of viral proteins in the HIV infected brain have been studied extensively as a key to understanding HIV-associated neurocognitive disorders (HAND). However, their comprehensive role in the context of intersecting substance use and neurocircuitry of the reward pathway and HAND has yet to be fully explained. Use of methamphetamines, cocaine, or opioids in the context of HIV infection have been shown to lead to a faster progression of HAND. Glutamatergic, dopaminergic, and GABAergic systems are implicated in the development of HAND-induced cognitive impairments. A thorough review of scientific literature exploring the variety of mechanisms in which these drugs exert their effects on the HIV brain and astrocytes has revealed marked areas of convergence in overexcitation leading to increased drug-seeking behavior, inflammation, apoptosis, and irreversible neurotoxicity. The present review investigates astrocytes, the neural pathways, and mechanisms of drug disruption that ultimately play a larger holistic role in terms of HIV progression and drug use. There are opportunities for future research, therapeutic intervention, and preventive strategies to diminish HAND in the subset population of patients with HIV and substance use disorder.
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Affiliation(s)
- Jessalyn Pla-Tenorio
- Ponce Health Sciences University, School of Medicine, Department of Basic Sciences, 395 Industrial Reparada, Zona 2, Ponce, PR, 00716, Puerto Rico
| | - Angela M. Roig
- Seattle Children's Hospital, MS OC.7.830, 4800 Sand Point Way NE, Seattle, WA, 98105-0371, United States
| | - Paulina A. García-Cesaní
- Bella Vista Hospital, Family Medicine Residency, Carr. 349 Km 2.7, Cerro Las Mesas, Mayaguez, PR, 00681, Puerto Rico
| | - Luis A. Santiago
- Ponce Health Sciences University, School of Medicine, Department of Basic Sciences, 395 Industrial Reparada, Zona 2, Ponce, PR, 00716, Puerto Rico
| | - Marian T. Sepulveda-Orengo
- Ponce Health Sciences University, School of Medicine, Department of Basic Sciences, 395 Industrial Reparada, Zona 2, Ponce, PR, 00716, Puerto Rico
| | - Richard J. Noel
- Ponce Health Sciences University, School of Medicine, Department of Basic Sciences, 395 Industrial Reparada, Zona 2, Ponce, PR, 00716, Puerto Rico
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Yang CS, Wu MC, Lai MC, Wu SN, Huang CW. Identification of New Antiseizure Medication Candidates in Preclinical Animal Studies. Int J Mol Sci 2023; 24:13143. [PMID: 37685950 PMCID: PMC10487685 DOI: 10.3390/ijms241713143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 08/09/2023] [Accepted: 08/17/2023] [Indexed: 09/10/2023] Open
Abstract
Epilepsy is a multifactorial neurologic disease that often leads to many devastating disabilities and an enormous burden on the healthcare system. Until now, drug-resistant epilepsy has presented a major challenge for approximately 30% of the epileptic population. The present article summarizes the validated rodent models of seizures employed in pharmacological researches and comprehensively reviews updated advances of novel antiseizure candidates in the preclinical phase. Newly discovered compounds that demonstrate antiseizure efficacy in preclinical trials will be discussed in the review. It is inspiring that several candidates exert promising antiseizure activities in drug-resistant seizure models. The representative compounds consist of derivatives of hybrid compounds that integrate multiple approved antiseizure medications, novel positive allosteric modulators targeting subtype-selective γ-Aminobutyric acid type A receptors, and a derivative of cinnamamide. Although the precise molecular mechanism, pharmacokinetic properties, and safety are not yet fully clear in every novel antiseizure candidate, the adapted approaches to design novel antiseizure medications provide new insights to overcome drug-resistant epilepsy.
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Affiliation(s)
- Chih-Sheng Yang
- Department of Neurology, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung City 42743, Taiwan;
- School of Post-Baccalaureate Chinese Medicine, Tzu Chi University, Hualien City 97004, Taiwan
| | - Man-Chun Wu
- Department of Family Medicine and Preventive Medicine Center, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung City 42743, Taiwan
| | - Ming-Chi Lai
- Department of Pediatrics, Chi-Mei Medical Center, Tainan City 71004, Taiwan;
| | - Sheng-Nan Wu
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan City 70101, Taiwan;
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan City 70101, Taiwan
| | - Chin-Wei Huang
- Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan City 70101, Taiwan
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Duran M, Aykaç S, Eliaçık S. Evaluation of ganglion cell complex and retinal nerve fiber layer thinning in epilepsy patients. Indian J Ophthalmol 2023; 71:3053-3058. [PMID: 37530280 PMCID: PMC10538845 DOI: 10.4103/ijo.ijo_2802_22] [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] [Indexed: 08/03/2023] Open
Abstract
Purpose This study aimed to compare the perimacular ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer (RNFL) thickness measurements of epileptic and healthy individuals. Methods The right eyes of 38 epileptic and 38 healthy individuals who had been using antiepileptic drugs (AEDs) for at least 1 year were included in the study. Central macular thickness, perimacular GCC thickness and volume, and peripapillary retinal nerve fiber layers were measured by optical coherence tomography (OCT) device. Perimacular 1, 3, and 6 mm circle diameters of Early Treatment of Diabetic Retinopathy Study (ETDRS. ) were selected for GCC measurements. Results In epilepsy patients, GCC was significantly lower in the 3 mm superior quadrant and 6 mm in all quadrants compared to the control group (P < 0.05). RNFL was significantly thinner in epilepsy patients only in the temporal-inferior quadrant (P < 0.05). There was no significant difference between the patients who received AEDs as monotherapy and polytherapy (P > 0.05). Conclusion We found that epilepsy patients had significant thinning in the GCC layers and temporal-inferior quadrant of RNFL compared to the control group. Our findings from the study show that early retinal changes in epilepsy patients, especially perimacular GCC layers, can be followed up with OCT.
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Affiliation(s)
- Mustafa Duran
- Department of Ophthalmology, Minister of Health Hitit University Erol Olçok Education and Research Hospital, Çorum, Turkey
| | - Serdar Aykaç
- Department of Neurology, Hitit University Faculty of Medicine, Çorum, Turkey
| | - Sinan Eliaçık
- Department of Neurology, Hitit University Faculty of Medicine, Çorum, Turkey
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Feja M, Meller S, Deking LS, Kaczmarek E, During MJ, Silverman RB, Gernert M. OV329, a novel highly potent γ-aminobutyric acid aminotransferase inactivator, induces pronounced anticonvulsant effects in the pentylenetetrazole seizure threshold test and in amygdala-kindled rats. Epilepsia 2021; 62:3091-3104. [PMID: 34617595 DOI: 10.1111/epi.17090] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/23/2021] [Accepted: 09/23/2021] [Indexed: 11/29/2022]
Abstract
OBJECTIVE An attractive target to interfere with epileptic brain hyperexcitability is the enhancement of γ-aminobutyric acidergic (GABAergic) inhibition by inactivation of the GABA-metabolizing enzyme GABA aminotransferase (GABA-AT). GABA-AT inactivators were designed to control seizures by raising brain GABA levels. OV329, a novel drug candidate for the treatment of epilepsy and addiction, has been shown in vitro to be substantially more potent as a GABA-AT inactivator than vigabatrin, an antiseizure drug approved as an add-on therapy for adult patients with refractory complex partial seizures and monotherapy for pediatric patients with infantile spasms. Thus, we hypothesized that OV329 should produce pronounced anticonvulsant effects in two different rat seizure models. METHODS We therefore examined the effects of OV329 (5, 20, and 40 mg/kg ip) on the seizure threshold of female Wistar Unilever rats, using the timed intravenous pentylenetetrazole (ivPTZ) seizure threshold model as a seizure test particularly sensitive to GABA-potentiating manipulations, and amygdala-kindled rats as a model of difficult-to-treat temporal lobe epilepsy. RESULTS GABA-AT inactivation by OV329 clearly increased the threshold of both ivPTZ-induced and amygdala-kindled seizures. OV329 further showed a 30-fold greater anticonvulsant potency on ivPTZ-induced myoclonic jerks and clonic seizures compared to vigabatrin investigated previously. Notably, all rats were responsive to OV329 in both seizure models. SIGNIFICANCE These results reveal an anticonvulsant profile of OV329 that appears to be superior in both potency and efficacy to vigabatrin and highlight OV329 as a highly promising candidate for the treatment of seizures and pharmacoresistant epilepsies.
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Affiliation(s)
- Malte Feja
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
| | - Sebastian Meller
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Lillian S Deking
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Edith Kaczmarek
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany
| | | | - Richard B Silverman
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA.,Department of Pharmacology, Chemistry of Life Processes Institute, Northwestern University, Chicago, Illinois, USA
| | - Manuela Gernert
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
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van der Poest Clement E, Jansen FE, Braun KPJ, Peters JM. Update on Drug Management of Refractory Epilepsy in Tuberous Sclerosis Complex. Paediatr Drugs 2020; 22:73-84. [PMID: 31912454 DOI: 10.1007/s40272-019-00376-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Tuberous sclerosis complex (TSC) is a genetic neurocutaneous disorder with epilepsy as a common and early presenting symptom. The neurological phenotype, however, is variable and unpredictable. Early and refractory seizures, infantile spasms in particular, are associated with a poor neurological outcome. Preliminary data suggests early and aggressive seizure control may mitigate the detrimental neurodevelopmental effects of epilepsy. For infantile spasms, vigabatrin is the first line of treatment, and steroids and classic antiepileptic drugs (AEDs) are suitable for second line. Based on retrospective data, vigabatrin should be considered for other indications, especially in infants with focal seizures, as this may prevent infantile spasms, but also in children and adults with epileptic spasms and tonic seizures. Otherwise, for most seizure types, treatment is similar to that for patients without TSC, including the use of novel AEDs, although limited data are available. Three major developments are changing the field of epilepsy management in TSC. First, final recommendations on preventive treatment with vigabatrin will result from two multicenter trials in the US (PREVeNT, clinicaltrials.gov #NCT02849457) and Europe (EPISTOP, clinicaltrials.gov #NCT02098759). Second, treatment with everolimus, an inhibitor of the mechanistic target of rapamycin (mTOR), reduced seizures when compared to placebo. Further, mTOR inhibitors may have an overall disease-modifying effect. Third, the role of cannabidiol in the treatment of refractory seizures in TSC is yet to be established. With treatment recommendations in TSC, we keep an eye on the prize for the broader field of pediatric epilepsy: the lessons learned from TSC are likely applicable to other epileptic encephalopathies.
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Affiliation(s)
| | - Floor E Jansen
- Department of Child Neurology, University Medical Center Utrecht Brain Center, Utrecht, The Netherlands
| | - Kees P J Braun
- Department of Child Neurology, University Medical Center Utrecht Brain Center, Utrecht, The Netherlands
| | - Jurriaan M Peters
- Division of Epilepsy and Clinical Neurophysiology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Ave, FE9, Boston, 02115, USA.
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Objective Derivation of the Morphology and Staging of Visual Field Loss Associated with Long-Term Vigabatrin Therapy. CNS Drugs 2019; 33:817-829. [PMID: 31250314 DOI: 10.1007/s40263-019-00634-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND The morphology and between-eye symmetry of the visual field loss associated with the antiepileptic drug vigabatrin (VAVFL) has received little attention. OBJECTIVE Our objective was to model the appearance and ensuing staging of VAVFL derived with the European Medicines Agency-approved perimetric protocol. METHODS This was a retrospective, cross-sectional, observational study that identified 123 adults who had received vigabatrin for refractory seizures and who had no evidence of co-existing retino-geniculo-cortical visual pathway abnormality. A further 38 adults with refractory seizures and identical inclusion criteria but no exposure to vigabatrin acted as controls. For each group, the median outcome at each stimulus location in each eye (of absolute loss, relative loss or Pattern Deviation probability level, as appropriate) was derived for each successive ten pairs of fields, ranked for severity. Between-eye symmetry was quantified by an index that accounted for severity of loss and that was referenced to the likelihood of the occurrence of symmetry due to chance. RESULTS The modelled VAVFL was bilateral and highly symmetrical and was described by six stages that were all independent of the extent of vigabatrin exposure. The loss originated in the extreme temporal periphery and encroached centripetally along all meridians towards fixation. The initial appearance within the central field (Stage 2) occurred inferior-nasally. Subsequent stages exhibited increasing loss, which was greater nasally than temporally. Stage 6 described concentric loss extending to approximately 15° eccentricity from fixation. CONCLUSION The model exhibited a consistent pattern of VAVFL. The staging of the loss could assist the risk:benefit analysis of vigabatrin for the treatment of epilepsy.
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Wild JM, Aljarudi S, Smith PEM, Knupp C. The Topographical Relationship between Visual Field Loss and Peripapillary Retinal Nerve Fibre Layer Thinning Arising from Long-Term Exposure to Vigabatrin. CNS Drugs 2019; 33:161-173. [PMID: 30637668 DOI: 10.1007/s40263-018-0583-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND The antiepileptic drug vigabatrin is associated with characteristic visual field loss (VAVFL) and thinning of the peripapillary retinal nerve fibre layer (PPRNFL); however, the relationship is equivocal. OBJECTIVE The aim of this study was to determine the function-structure relationship associated with long-term exposure to vigabatrin, thereby improving the risk/benefit analysis of the drug. METHODS A cross-sectional observational design identified 40 adults who had received long-term vigabatrin for refractory seizures, who had no evidence of co-existing retino-geniculo-cortical visual pathway abnormality, and who had undergone a standardized protocol of perimetry and of optical coherence tomography (OCT) of the PPRNFL. Vigabatrin toxicity was defined as the presence of VAVFL. The function-structure relationship for the superior and inferior retinal quadrants was evaluated by two established models applicable to other optic neuropathies. RESULTS The function-structure relationship for each model was consistent with an optic neuropathy. PPRNFL thinning, expressed in micrometres, asymptoted at an equivalent visual field loss of worse than approximately - 10.0 dB, thereby preventing assessment of more substantial thinning. Transformation of the outcomes to retinal ganglion cell soma and axon estimates, respectively, resulted in a linear relationship. CONCLUSIONS Functional and structural abnormality is strongly related in individuals with vigabatrin toxicity and no evidence of visual pathway comorbidity, thereby implicating retinal ganglion cell dysfunction. OCT affords a limited measurement range compared with perimetry: severity cannot be directly assessed when the PPRNFL quadrant thickness is less than approximately 65 µm, depending on the tomographer. This limitation can be overcome by transformation of thickness to remaining axons, an outcome requiring input from perimetry.
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Affiliation(s)
- John M Wild
- College of Biomedical Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK.
| | - Saleh Aljarudi
- College of Biomedical Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK.,Dhahran Eye Specialist Hospital, Dhahran, 7500, Saudi Arabia
| | - Philip E M Smith
- Alan Richens Unit, Welsh Epilepsy Centre, University Hospital of Wales, Heath Park, Cardiff, CF14 4XW, UK
| | - Carlo Knupp
- College of Biomedical Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK
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Rodrigues C, Chiron C, Ounissi M, Dulac O, Gaillard S, Nabbout R, Jullien V. Pharmacokinetic evaluation of vigabatrin dose for the treatment of refractory focal seizures in children using adult and pediatric data. Epilepsy Res 2019; 150:38-45. [PMID: 30639958 DOI: 10.1016/j.eplepsyres.2019.01.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 12/13/2018] [Accepted: 01/06/2019] [Indexed: 11/27/2022]
Abstract
Vigabatrin is indicated as adjunctive therapy for refractory focal seizures. For children, European recommendations indicate maintenance doses varying from 30 to 100 mg/kg/day for this indication. Since cumulated dose was associated with retinal toxicity, it is essential to administrate the lowest effective dose to patients. This work was conducted with the purpose to determine the pediatric doses of vigabatrin that allow a similar exposure than effective doses in adults (2-3 g/day) through a pharmacokinetic (PK) study, using both pediatric and adult data. For this study, we focused on the active S(+) enantiomer of vigabatrin. First, the adult effective exposition range of vigabatrin-S was determined from an adult PK model. Then, this same model was scaled to the pediatric population using allometry and maturation principles to account for growth and development. The ability of the model to predict pediatric data was assessed by comparing population predictions with observed pediatric data. Finally, the extrapolated pediatric model was used to simulate pediatric expositions which were compared to the adult exposition range (36.5-77.9 mg.h/L). From those simulations, we determined that, for children aged between 3 months and 18 years, doses between 40 and 50 mg/kg/day allow vigabatrin-S expositions similar to those found in adults at the recommended posology. We proposed those doses as optimal maintenance doses that may be increased, if necessary, by slow titration.
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Affiliation(s)
- Christelle Rodrigues
- INSERM U1129, Paris, France; Paris Descartes University, CEA, Gif-sur-Yvette, France.
| | - Catherine Chiron
- INSERM U1129, Paris, France; Paris Descartes University, CEA, Gif-sur-Yvette, France.
| | - Marwa Ounissi
- INSERM U1129, Paris, France; Paris Descartes University, CEA, Gif-sur-Yvette, France.
| | - Olivier Dulac
- INSERM U1129, Paris, France; Paris Descartes University, CEA, Gif-sur-Yvette, France.
| | - Ségolène Gaillard
- Centre d'Investigation Clinique - CIC 1407- Hospices Civils de Lyon, France.
| | - Rima Nabbout
- INSERM U1129, Paris, France; Paris Descartes University, CEA, Gif-sur-Yvette, France; Reference Centre for Rare Epilepsies, APHP, Necker-Enfants Malades Hospital, Imagine Institute, Paris, France.
| | - Vincent Jullien
- INSERM U1129, Paris, France; Paris Descartes University, CEA, Gif-sur-Yvette, France; Service de Pharmacologie, Hôpital Européen Georges Pompidou, 20 rue Leblanc, 75015 Paris, France.
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10
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Bialer M, Johannessen SI, Koepp MJ, Levy RH, Perucca E, Tomson T, White HS. Progress report on new antiepileptic drugs: A summary of the Fourteenth Eilat Conference on New Antiepileptic Drugs and Devices (EILAT XIV). I. Drugs in preclinical and early clinical development. Epilepsia 2018; 59:1811-1841. [DOI: 10.1111/epi.14557] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/08/2018] [Accepted: 08/08/2018] [Indexed: 01/06/2023]
Affiliation(s)
- Meir Bialer
- Faculty of Medicine; School of Pharmacy and David R. Bloom Center for Pharmacy; Institute for Drug Research; Hebrew University of Jerusalem; Jerusalem Israel
| | - Svein I. Johannessen
- National Center for Epilepsy; Sandvika Norway
- Department of Pharmacology; Oslo University Hospital; Oslo Norway
| | - Matthias J. Koepp
- Department of Clinical and Experimental Epilepsy; UCL Institute of Neurology; London UK
| | - René H. Levy
- Departments of Pharmaceutics and Neurological Surgery; University of Washington; Seattle Washington
| | - Emilio Perucca
- Department of Internal Medicine and Therapeutics; University of Pavia; Pavia Italy
- IRCCS Mondino Foundation; Pavia Italy
| | - Torbjörn Tomson
- Department of Clinical Neuroscience; Karolinska Institute; Stockholm Sweden
| | - H. Steve White
- Department of Pharmacy; School of Pharmacy; University of Washington; Seattle Washington
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Ounissi M, Rodrigues C, Bienayme H, Duhamel P, Pons G, Dulac O, Nabbout R, Chiron C, Jullien V. Proposition of a Minimal Effective Dose of Vigabatrin for the Treatment of Infantile Spasms Using Pediatric and Adult Pharmacokinetic Data. J Clin Pharmacol 2018; 59:177-188. [DOI: 10.1002/jcph.1309] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 08/03/2018] [Indexed: 12/22/2022]
Affiliation(s)
- Marwa Ounissi
- INSERM U1129, Paris, France; Paris Descartes University, CEA; Gif-sur-Yvette France
| | - Christelle Rodrigues
- INSERM U1129, Paris, France; Paris Descartes University, CEA; Gif-sur-Yvette France
| | | | - Paul Duhamel
- INSERM U1129, Paris, France; Paris Descartes University, CEA; Gif-sur-Yvette France
| | - Gérard Pons
- INSERM U1129, Paris, France; Paris Descartes University, CEA; Gif-sur-Yvette France
| | - Olivier Dulac
- INSERM U1129, Paris, France; Paris Descartes University, CEA; Gif-sur-Yvette France
- Reference Centre for Rare Epilepsies; APHP; Necker-Enfants Malades Hospital; Imagine institute; Paris France
| | - Rima Nabbout
- INSERM U1129, Paris, France; Paris Descartes University, CEA; Gif-sur-Yvette France
- Reference Centre for Rare Epilepsies; APHP; Necker-Enfants Malades Hospital; Imagine institute; Paris France
| | - Catherine Chiron
- INSERM U1129, Paris, France; Paris Descartes University, CEA; Gif-sur-Yvette France
- Reference Centre for Rare Epilepsies; APHP; Necker-Enfants Malades Hospital; Imagine institute; Paris France
| | - Vincent Jullien
- INSERM U1129, Paris, France; Paris Descartes University, CEA; Gif-sur-Yvette France
- Service de pharmacologie; Hôpital Européen Georges Pompidou; Paris France
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Moschitto MJ, Silverman RB. Synthesis of ( S)-3-Amino-4-(difluoromethylenyl)-cyclopent-1-ene-1-carboxylic Acid (OV329), a Potent Inactivator of γ-Aminobutyric Acid Aminotransferase. Org Lett 2018; 20:4589-4592. [PMID: 30009604 DOI: 10.1021/acs.orglett.8b01872] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
( S)-3-Amino-4-(difluoromethylenyl)cyclopent-1-ene-1-carboxylic acid (OV329, 1) is being developed for the treatment of epilepsy and addiction. The previous 14-step synthesis of OV329 was low yielding, involved an unselective α-elimination to form the cyclopentene, required the use of tert-butyllithium, and produced toxic selenium byproducts in the penultimate step. A new synthesis, which avoids the aforementioned issues, was carried out on large scale, reducing the step count from 14 to 9 steps and increasing the overall yield from 3.7% to 8.1%.
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Affiliation(s)
- Matthew J Moschitto
- Departments of Chemistry and Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, and Center for Developmental Therapeutics , Northwestern University , Evanston , Illinois 60208 , United States
| | - Richard B Silverman
- Departments of Chemistry and Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, and Center for Developmental Therapeutics , Northwestern University , Evanston , Illinois 60208 , United States
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Silverman RB. Design and Mechanism of GABA Aminotransferase Inactivators. Treatments for Epilepsies and Addictions. Chem Rev 2018; 118:4037-4070. [PMID: 29569907 DOI: 10.1021/acs.chemrev.8b00009] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
When the brain concentration of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) diminishes below a threshold level, the excess neuronal excitation can lead to convulsions. This imbalance in neurotransmission can be corrected by inhibition of the enzyme γ-aminobutyric acid aminotransferase (GABA-AT), which catalyzes the conversion of GABA to the excitatory neurotransmitter l-glutamic acid. It also has been found that raising GABA levels can antagonize the rapid elevation and release of dopamine in the nucleus accumbens, which is responsible for the reward response in addiction. Therefore, the design of new inhibitors of GABA-AT, which increases brain GABA levels, is an important approach to new treatments for epilepsy and addiction. This review summarizes findings over the last 40 or so years of mechanism-based inactivators (unreactive compounds that require the target enzyme to catalyze their conversion to the inactivating species, which inactivate the enzyme prior to their release) of GABA-AT with emphasis on their catalytic mechanisms of inactivation, presented according to organic chemical mechanism, with minimal pharmacology, except where important for activity in epilepsy and addiction. Patents, abstracts, and conference proceedings are not covered in this review. The inactivation mechanisms described here can be applied to the inactivations of a wide variety of unrelated enzymes.
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Affiliation(s)
- Richard B Silverman
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Center for Developmental Therapeutics , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208-3113 , United States
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Juncosa JI, Takaya K, Le HV, Moschitto MJ, Weerawarna PM, Mascarenhas R, Liu D, Dewey SL, Silverman RB. Design and Mechanism of (S)-3-Amino-4-(difluoromethylenyl)cyclopent-1-ene-1-carboxylic Acid, a Highly Potent γ-Aminobutyric Acid Aminotransferase Inactivator for the Treatment of Addiction. J Am Chem Soc 2018; 140:2151-2164. [PMID: 29381352 PMCID: PMC5812813 DOI: 10.1021/jacs.7b10965] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
γ-Aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the central nervous system. Inhibition of GABA aminotransferase (GABA-AT), a pyridoxal 5'-phosphate (PLP)-dependent enzyme that degrades GABA, has been established as a possible strategy for the treatment of substance abuse. The raised GABA levels that occur as a consequence of this inhibition have been found to antagonize the rapid release of dopamine in the ventral striatum (nucleus accumbens) that follows an acute challenge by an addictive substance. In addition, increased GABA levels are also known to elicit an anticonvulsant effect in patients with epilepsy. We previously designed the mechanism-based inactivator (1S,3S)-3-amino-4-difluoromethylenyl-1-cyclopentanoic acid (2), now called CPP-115, that is 186 times more efficient in inactivating GABA-AT than vigabatrin, the only FDA-approved drug that is an inactivator of GABA-AT. CPP-115 was found to have high therapeutic potential for the treatment of cocaine addiction and for a variety of epilepsies, has successfully completed a Phase I safety clinical trial, and was found to be effective in the treatment of infantile spasms (West syndrome). Herein we report the design, using molecular dynamics simulations, synthesis, and biological evaluation of a new mechanism-based inactivator, (S)-3-amino-4-(difluoromethylenyl)cyclopent-1-ene-1-carboxylic acid (5), which was found to be almost 10 times more efficient as an inactivator of GABA-AT than CPP-115. We also present the unexpected crystal structure of 5 bound to GABA-AT, as well as computational analyses used to assist the structure elucidation process. Furthermore, 5 was found to have favorable pharmacokinetic properties and low off-target activities. In vivo studies in freely moving rats showed that 5 was dramatically superior to CPP-115 in suppressing the release of dopamine in the corpus striatum, which occurs subsequent to either an acute cocaine or nicotine challenge. Compound 5 also attenuated increased metabolic demands (neuronal glucose metabolism) in the hippocampus, a brain region that encodes spatial information concerning the environment in which an animal receives a reinforcing or aversive drug. This multidisciplinary computational design to preclinical efficacy approach should be applicable to the design and improvement of mechanism-based inhibitors of other enzymes whose crystal structures and inactivation mechanisms are known.
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Affiliation(s)
- Jose I. Juncosa
- Departments of Chemistry and Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, and Center for Developmental Therapeutics, Northwestern University, Evanston, Illinois 60208, United States
| | - Kenji Takaya
- Departments of Chemistry and Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, and Center for Developmental Therapeutics, Northwestern University, Evanston, Illinois 60208, United States
| | - Hoang V. Le
- Departments of Chemistry and Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, and Center for Developmental Therapeutics, Northwestern University, Evanston, Illinois 60208, United States
| | - Matthew J. Moschitto
- Departments of Chemistry and Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, and Center for Developmental Therapeutics, Northwestern University, Evanston, Illinois 60208, United States
| | - Pathum M. Weerawarna
- Departments of Chemistry and Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, and Center for Developmental Therapeutics, Northwestern University, Evanston, Illinois 60208, United States
| | - Romila Mascarenhas
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States
| | - Dali Liu
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States
| | - Stephen L. Dewey
- Center for Neurosciences, Laboratory for Behavioral and Molecular Neuroimaging, Feinstein Institute for Medical Research, North Shore-LIJ Health System, Manhasset, New York 11030, United States
| | - Richard B. Silverman
- Departments of Chemistry and Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, and Center for Developmental Therapeutics, Northwestern University, Evanston, Illinois 60208, United States
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Venceslas D, Corinne R. A Mesiotemporal Lobe Epilepsy Mouse Model. Neurochem Res 2017; 42:1919-1925. [PMID: 28332054 DOI: 10.1007/s11064-017-2239-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 03/16/2017] [Accepted: 03/16/2017] [Indexed: 01/25/2023]
Abstract
Among the different forms of epilepsies, mesiotemporal lobe epilepsy (MTLE) is one of the most common and represents the main pharmaco-resistant form of epilepsy. There is therefore an urgent need to better understand this form of epilepsy to develop better anti-epileptic drugs. Many rodent models are mimicking some aspects of the human temporal lobe epilepsy but only few are addressing most of the human mesiotemporal lobe epilepsy. In this article, we describe the main characteristics of a mouse of model of mesial temporal lobe epilepsy. This model is generated by a single injection of kainic acid into the dorsal hippocampus which reproduces most of the morphological and electrophysiological features of human MTLE in a mouse. This model may help to better understand mesial temporal lobe epilepsy and the development of new therapeutic drugs.
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Affiliation(s)
- Duveau Venceslas
- SynapCell SAS, Bâtiment Biopolis, 5 Avenue du Grand Sablon, 38700, La Tronche, France.
| | - Roucard Corinne
- SynapCell SAS, Bâtiment Biopolis, 5 Avenue du Grand Sablon, 38700, La Tronche, France
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Hatori T, Sugiyama Y, Yamashita S, Hirakubo Y, Nonaka K, Ichihashi K. Vigabatrin Therapy for Infantile Spasms in a Case of Cardiofaciocutaneous Syndrome with Cardiac Hypertrophy Developing during Adrenocorticotropic Hormone Treatment. J NIPPON MED SCH 2016; 83:167-71. [PMID: 27680485 DOI: 10.1272/jnms.83.167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In a patient with cardiofaciocutaneous syndrome complicated by intractable infantile spasms (West syndrome), cardiac hypertrophy developed during adrenocorticotropic hormone treatment. Various types of antiepileptic drugs, intravenous immunoglobulin, thyrotropin releasing hormone, and a ketogenic diet were ineffective in this case. However, vigabatrin both decreased clinical seizures and improved electroencephalogram findings. Although vigabatrin has not been approved for use in Japan, the results in the present case suggest that this drug should be considered as an alternative therapy for cases of infantile spasms associated with syndromes involving cardiomyopathy or its potential risk factors, such as cardiofaciocutaneous syndrome.
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Affiliation(s)
- Takayuki Hatori
- Department of Pediatrics, Jichi Medical University Saitama Medical Center
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17
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Hébert-Lalonde N, Carmant L, Major P, Roy MS, Lassonde M, Saint-Amour D. Electrophysiological Evidences of Visual Field Alterations in Children Exposed to Vigabatrin Early in Life. Pediatr Neurol 2016; 59:47-53. [PMID: 27105764 DOI: 10.1016/j.pediatrneurol.2016.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 03/04/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND We assessed central and peripheral visual field processing in children with epilepsy who were exposed to vigabatrin during infancy. METHODS Steady-state visual evoked potentials and pattern electroretinograms to field-specific radial checkerboards flickering at two cycle frequencies (7.5 and 6 Hz for central and peripheral stimulations, respectively) were recorded from Oz and at the eye in seven school-age children (10.1 ± 3.5 years) exposed to vigabatrin early in life, compared with children early exposed to other antiepileptic drugs (n = 9) and healthy children (n = 8). The stimulation was made of two concentric circles (0 to 5 and 30 to 60 degrees of angle) and presented at four contrast levels (96%, 64%, 32%, and 16%). RESULTS Ocular responses were similar in all groups for central but not for the peripheral stimulations, which were significantly lower in the vigabatrin-exposed group at high contrast level. This peripheral retinal response was negatively correlated to vigabatrin exposure duration. Cortical responses to central stimulations, including contrast response functions in the children with epilepsy in both groups, were lower than those in normally developing children. CONCLUSIONS Alteration of ocular processing was found only in the vigabatrin-exposed children. Central cortical processing, however, was impaired in both epileptic groups, with more pronounced effects in vigabatrin-exposed children. Our study suggests that asymptomatic long-term visual toxicity may still be present at school age, even several years after discontinuation of drug therapy.
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Affiliation(s)
- Noémie Hébert-Lalonde
- Department of Psychology, Université de Montréal, Montreal, Quebec, Canada; Research Center, CHU Sainte-Justine, Montreal, Quebec, Canada
| | - Lionel Carmant
- Research Center, CHU Sainte-Justine, Montreal, Quebec, Canada; Division of Neurology, Department of Pediatrics, Sainte-Justine Hospital, Université de Montréal, Montreal, Quebec, Canada
| | - Philippe Major
- Research Center, CHU Sainte-Justine, Montreal, Quebec, Canada; Division of Neurology, Department of Pediatrics, Sainte-Justine Hospital, Université de Montréal, Montreal, Quebec, Canada
| | | | - Maryse Lassonde
- Department of Psychology, Université de Montréal, Montreal, Quebec, Canada; Research Center, CHU Sainte-Justine, Montreal, Quebec, Canada
| | - Dave Saint-Amour
- Research Center, CHU Sainte-Justine, Montreal, Quebec, Canada; Department of Ophtalmology, Université de Montréal, Montreal, Quebec, Canada; Department of Psychology, Université du Québec à Montréal, Montreal, Quebec, Canada.
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18
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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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19
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Lee H, Le HV, Wu R, Doud E, Sanishvili R, Kellie JF, Compton PD, Pachaiyappan B, Liu D, Kelleher NL, Silverman RB. Mechanism of Inactivation of GABA Aminotransferase by (E)- and (Z)-(1S,3S)-3-Amino-4-fluoromethylenyl-1-cyclopentanoic Acid. ACS Chem Biol 2015; 10:2087-98. [PMID: 26110556 DOI: 10.1021/acschembio.5b00212] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
When γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the mammalian central nervous system, falls below a threshold level, seizures occur. One approach to raise GABA concentrations is to inhibit GABA aminotransferase (GABA-AT), a pyridoxal 5'-phosphate-dependent enzyme that degrades GABA. We have previously developed (1S,3S)-3-amino-4-difluoromethylene-1-cyclopentanoic acid (CPP-115), which is 186 times more efficient in inactivating GABA-AT than vigabatrin, the only FDA-approved inactivator of GABA-AT. We also developed (E)- and (Z)-(1S,3S)-3-amino-4-fluoromethylenyl-1-cyclopentanoic acid (1 and 2, respectively), monofluorinated analogs of CPP-115, which are comparable to vigabatrin in inactivating GABA-AT. Here, we report the mechanism of inactivation of GABA-AT by 1 and 2. Both produce a metabolite that induces disruption of the Glu270-Arg445 salt bridge to accommodate interaction between the metabolite formyl group and Arg445. This is the second time that Arg445 has interacted with a ligand and is involved in GABA-AT inactivation, thereby confirming the importance of Arg445 in future inactivator design.
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Affiliation(s)
- Hyunbeom Lee
- Departments
of Chemistry and Molecular Biosciences, Chemistry of Life Processes
Institute, and the Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208, United States
| | - Hoang V. Le
- Departments
of Chemistry and Molecular Biosciences, Chemistry of Life Processes
Institute, and the Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208, United States
| | - Rui Wu
- Department
of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States
| | - Emma Doud
- Departments
of Chemistry and Molecular Biosciences, and the Proteomics Center
of Excellence, Northwestern University, Evanston, Illinois 60208, United States
| | - Ruslan Sanishvili
- X-ray
Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - John F. Kellie
- Departments
of Chemistry and Molecular Biosciences, and the Proteomics Center
of Excellence, Northwestern University, Evanston, Illinois 60208, United States
| | - Phillip D. Compton
- Departments
of Chemistry and Molecular Biosciences, and the Proteomics Center
of Excellence, Northwestern University, Evanston, Illinois 60208, United States
| | - Boobalan Pachaiyappan
- Departments
of Chemistry and Molecular Biosciences, Chemistry of Life Processes
Institute, and the Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208, United States
| | - Dali Liu
- Department
of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States
| | - Neil L. Kelleher
- Departments
of Chemistry and Molecular Biosciences, and the Proteomics Center
of Excellence, Northwestern University, Evanston, Illinois 60208, United States
| | - Richard B. Silverman
- Departments
of Chemistry and Molecular Biosciences, Chemistry of Life Processes
Institute, and the Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208, United States
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20
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Le HV, Hawker DD, Wu R, Doud E, Widom J, Sanishvili R, Liu D, Kelleher NL, Silverman RB. Design and mechanism of tetrahydrothiophene-based γ-aminobutyric acid aminotransferase inactivators. J Am Chem Soc 2015; 137:4525-33. [PMID: 25781189 PMCID: PMC4390550 DOI: 10.1021/jacs.5b01155] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Low levels of γ-aminobutyric acid (GABA), one of two major neurotransmitters that regulate brain neuronal activity, are associated with many neurological disorders, such as epilepsy, Parkinson's disease, Alzheimer's disease, Huntington's disease, and cocaine addiction. One of the main methods to raise the GABA level in human brain is to use small molecules that cross the blood-brain barrier and inhibit the activity of γ-aminobutyric acid aminotransferase (GABA-AT), the enzyme that degrades GABA. We have designed a series of conformationally restricted tetrahydrothiophene-based GABA analogues with a properly positioned leaving group that could facilitate a ring-opening mechanism, leading to inactivation of GABA-AT. One compound in the series is 8 times more efficient an inactivator of GABA-AT than vigabatrin, the only FDA-approved inactivator of GABA-AT. Our mechanistic studies show that the compound inactivates GABA-AT by a new mechanism. The metabolite resulting from inactivation does not covalently bind to amino acid residues of GABA-AT but stays in the active site via H-bonding interactions with Arg-192, a π-π interaction with Phe-189, and a weak nonbonded S···O═C interaction with Glu-270, thereby inactivating the enzyme.
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Affiliation(s)
- Hoang V. Le
- Departments of Chemistry and Molecular Biosciences, Chemistry of Life Processes Institute, and the Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, IL 60208
| | - Dustin D. Hawker
- Departments of Chemistry and Molecular Biosciences, Chemistry of Life Processes Institute, and the Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, IL 60208
| | - Rui Wu
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, IL 60660
| | - Emma Doud
- Departments of Chemistry and Molecular Biosciences, and the Proteomics Center of Excellence, Northwestern University, Evanston, IL 60208
| | - Julia Widom
- Departments of Chemistry and Molecular Biosciences, Chemistry of Life Processes Institute, and the Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, IL 60208
| | - Ruslan Sanishvili
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439
| | - Dali Liu
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, IL 60660
| | - Neil L. Kelleher
- Departments of Chemistry and Molecular Biosciences, and the Proteomics Center of Excellence, Northwestern University, Evanston, IL 60208
| | - Richard B. Silverman
- Departments of Chemistry and Molecular Biosciences, Chemistry of Life Processes Institute, and the Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, IL 60208
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21
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Riikonen R, Rener-Primec Z, Carmant L, Dorofeeva M, Hollody K, Szabo I, Krajnc BS, Wohlrab G, Sorri I. Does vigabatrin treatment for infantile spasms cause visual field defects? An international multicentre study. Dev Med Child Neurol 2015; 57:60-7. [PMID: 25145415 DOI: 10.1111/dmcn.12573] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/03/2014] [Indexed: 11/30/2022]
Abstract
AIM The aim of this study was to examine whether vigabatrin treatment had caused visual field defects (VFDs) in children of school age who had received the drug in infancy. METHOD In total, 35 children (14 males, 21 females; median age 11y, SD 3.4y, range 8-23y) were examined by static Humphrey perimetry, Goldmann kinetic perimetry, or Octopus perimetry. The aetiologies of infantile spasms identified were tuberous sclerosis (n=10), other symptomatic causes (n=3), or cryptogenic (n=22). RESULTS Typical vigabatrin-attributed VFDs were found in 11 out of 32 (34%) children: in one out of 11 children (9%) who received vigabatrin for <1 year (group 1), in three out of 10 children (30%) who received vigabatrin for 12 to 24 months (group 2), and in seven out of 11 children (63%) who received vigabatrin treatment for longer than 2 years (group 3). VFDs were mild in five and severe in six children. Patients with tuberous sclerosis were at higher risk of VFDs (six out of 10 children). The mean cumulative doses of vigabatrin were 140.5, 758.8, and 2712g in group 1, 2, and 3, respectively. INTERPRETATION VFDs were found in 34% of the cohort of children in this study. The rate of VFD increased from 9% to 63% as duration of treatment increased. The results of this study showed that the risk-benefit ratio should always be considered when using vigabatrin.
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Affiliation(s)
- Raili Riikonen
- Children's Hospital, Kuopio University Hospital, Kuopio, Finland
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22
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Conway ML, Hosking SL, Zhu H, Cubbidge RP. Does the Swedish Interactive Threshold Algorithm (SITA) accurately map visual field loss attributed to vigabatrin? BMC Ophthalmol 2014; 14:166. [PMID: 25539569 PMCID: PMC4391113 DOI: 10.1186/1471-2415-14-166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 12/18/2014] [Indexed: 11/29/2022] Open
Abstract
Background Vigabatrin (VGB) is an anti-epileptic medication which has been linked to peripheral constriction of the visual field. Documenting the natural history associated with continued VGB exposure is important when making decisions about the risk and benefits associated with the treatment. Due to its speed the Swedish Interactive Threshold Algorithm (SITA) has become the algorithm of choice when carrying out Full Threshold automated static perimetry. SITA uses prior distributions of normal and glaucomatous visual field behaviour to estimate threshold sensitivity. As the abnormal model is based on glaucomatous behaviour this algorithm has not been validated for VGB recipients. We aim to assess the clinical utility of the SITA algorithm for accurately mapping VGB attributed field loss. Methods The sample comprised one randomly selected eye of 16 patients diagnosed with epilepsy, exposed to VGB therapy. A clinical diagnosis of VGB attributed visual field loss was documented in 44% of the group. The mean age was 39.3 years ± 14.5 years and the mean deviation was -4.76 dB ±4.34 dB. Each patient was examined with the Full Threshold, SITA Standard and SITA Fast algorithm. Results SITA Standard was on average approximately twice as fast (7.6 minutes) and SITA Fast approximately 3 times as fast (4.7 minutes) as examinations completed using the Full Threshold algorithm (15.8 minutes). In the clinical environment, the visual field outcome with both SITA algorithms was equivalent to visual field examination using the Full Threshold algorithm in terms of visual inspection of the grey scale plots , defect area and defect severity. Conclusions Our research shows that both SITA algorithms are able to accurately map visual field loss attributed to VGB. As patients diagnosed with epilepsy are often vulnerable to fatigue, the time saving offered by SITA Fast means that this algorithm has a significant advantage for use with VGB recipients. Electronic supplementary material The online version of this article (doi:10.1186/1471-2415-14-166) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Miriam L Conway
- Department of Optometry and Visual Science, City University London, Northampton Square, London, EC1V OHB, UK.
| | - Sarah L Hosking
- Department of Optometry University of Melbourne, University of Melbourne, 32 Gisborne Street, East Melbourne, VIC, 3002, Australia.
| | - Haogang Zhu
- Department of Optometry and Visual Science, City University London, Northampton Square, London, EC1V OHB, UK.
| | - Robert P Cubbidge
- Optometry & Vision Sciences, School of Life & Health Sciences, Aston University, Aston Triangle, Birmingham, B4 7ET, UK.
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Briggs SW, Mowrey W, Hall CB, Galanopoulou AS. CPP-115, a vigabatrin analogue, decreases spasms in the multiple-hit rat model of infantile spasms. Epilepsia 2013; 55:94-102. [PMID: 24321005 DOI: 10.1111/epi.12424] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2013] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Infantile spasms (IS) have poor outcomes and limited treatment options, including vigabatrin, a γ-aminobutyric acid (GABA) aminotransferase inactivator. Vigabatrin has been associated with retinal toxicity. A high affinity vigabatrin analogue (CPP-115; Catalyst Pharmaceutical Partners, Inc., Coral Gables, FL, U.S.A.) has shown lower risk of retinal toxicity. Here, we test the efficacy of CPP-115 in reducing spasms and its tolerability in the multiple-hit rat model of IS, in which daily vigabatrin reduced spasms for only one day, but was not well tolerated. METHODS Male rats were treated with the protocol of the multiple-hit model of IS on postnatal day 3 (PN3). Using a randomized, blinded, vehicle-controlled, dose-response study design, CPP-115 (0.1, 1, or 5 mg/kg intraperitoneally [i.p.]) or vehicle was given daily (PN4-12) or as a single injection (PN7) after spasm onset. Intermittent video- or video-electroencephalography (EEG) monitoring was done. Secondary end points included the following: daily weights, survival, performance on open field activity, surface righting time, and negative geotaxis (PN3-20), horizontal bar (PN13-20), and Barnes maze (PN16-19). Statistics used a linear mixed model of raw or normalized log-transformed data, taking into account the repeated observations on each animal. RESULTS The lower CPP-115 doses (0.1-1 mg/kg/day, PN4-12) reduced spasms between PN6 and 7 without increasing mortality. CPP-115 at 5 mg/kg/day (PN4-12) reduced spasms earlier (PN5), but was eventually lethal. A single CPP-115 injection (1 mg/kg, i.p.) decreased electroclinical spasms acutely but transiently. CPP-115 transiently improved the probability to >50% reduction of spasms, but did not accelerate spasm cessation. CPP-115 did not alter neurodevelopmental outcomes or visuospatial learning. SIGNIFICANCE We provide proof-of-concept evidence that CPP-115, a vigabatrin analogue, decreases spasms in the multiple-hit rat model of IS at considerably lower and better tolerated doses than vigabatrin did in our previous studies. Further optimization of the treatment protocol is needed. CPP-115 may be a promising new candidate treatment for IS with better tolerability than vigabatrin.
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Affiliation(s)
- Stephen W Briggs
- Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, New York, U.S.A; Laboratory of Developmental Epilepsy and Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, U.S.A
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24
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Wild JM, Fone DL, Aljarudi S, Lawthom C, Smith PEM, Newcombe RG, Lewis GD. Modelling the risk of visual field loss arising from long-term exposure to the antiepileptic drug vigabatrin: a cross-sectional approach. CNS Drugs 2013; 27:841-9. [PMID: 23990316 DOI: 10.1007/s40263-013-0100-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The antiepileptic drug vigabatrin has been used widely since 1989, but has only been approved for use in the US since 2009. The risk:benefit of vigabatrin is generally predicated upon an assumed frequency of associated visual field loss (VAVFL) of approximately 31 %. This estimate is based upon relatively short-term usage (up to 4-5 years) and it is essential to determine whether the frequency of VAVFL increases with longer-term usage. OBJECTIVE The aim of this study was to model, from cross-sectional evidence, over greater ranges of treatment duration and cumulative dose than previously evaluated, the risk (frequency) of VAVFL with increasing exposure to vigabatrin. STUDY DESIGN AND SETTING This was a retrospective cohort study undertaken in a regional hospital epilepsy clinic. PATIENTS The cohort comprised 147 consecutive patients treated with vigabatrin for refractory complex partial (focal) seizures, who had all undergone ophthalmological examination and who had undertaken perimetry, reliably, according to a standard and robust protocol. The visual field plots were evaluated masked to treatment duration and dose. MAIN OUTCOME MEASURE The risk (frequency) of VAVFL with increasing exposure to vigabatrin was modelled, from the cross-sectional evidence, by standard and plateau logistic regression. RESULTS The cohort comprised 80 females and 67 males (mean age 40.3 years, standard deviation 13.7). The median duration of vigabatrin exposure was 7.9 years (interquartile range 3.6-11.0, range 0.2-16.1 years); 46 patients (31 %) had received vigabatrin for over 10 years. Eighty-seven patients (59 %) exhibited VAVFL; the proportion with VAVFL was higher in males (66 %) than females (54 %). The plateau model for duration and for cumulative dose exhibited a better fit than the standard model (both p < 0.001). The modelled frequency of VAVFL increased with increasing exposure up to approximately 6 years duration and 5 kg cumulative dose, and plateaued at approximately 76 % (95 % CI 67-85) and 79 % (95 % CI 70-87), respectively. Severity of VAVFL, classified in terms of the visual field index Mean Deviation, was not significantly associated with either duration or cumulative dose of therapy. CONCLUSION Clinicians and patients, in enabling informed choice, should be alert to the possible substantial increased risk:benefit for VAVFL with increasing long-term exposure to vigabatrin and the ensuing increased cost:benefit resulting from the necessary additional visual assessments.
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Affiliation(s)
- John M Wild
- Cardiff Centre for Vision Sciences, College of Biomedical and Life Sciences, Cardiff University, Maindy Road, Cardiff, Wales, CF24 4HQ, UK,
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Cross JH, Kluger G, Lagae L. Advancing the management of childhood epilepsies. Eur J Paediatr Neurol 2013; 17:334-47. [PMID: 23558251 DOI: 10.1016/j.ejpn.2013.02.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 02/20/2013] [Accepted: 02/27/2013] [Indexed: 12/27/2022]
Abstract
Childhood epilepsies comprise a heterogeneous group of disorders and syndromes that vary in terms of severity, prognosis and treatment requirements. Effective management requires early, accurate recognition and diagnosis, and a holistic approach that addresses each individual's medical and psychosocial needs within the context of their overall health status and quality of life. With increasing understanding of underlying aetiologies, new approaches to management and treatment are emerging. For example, genetic testing is beginning to provide a tool to aid differential diagnosis and a means of predicting predisposition to particular types of epilepsy. Despite the availability of an increasing number of antiepileptic drugs (AEDs)--due not only to the development of new AEDs, but also to changes in regulatory requirements that have facilitated clinical development--seizure control and tolerability continue to be suboptimal in many patients, and there is therefore a continuing need for new treatment strategies. Surgery and other non-pharmacological treatments (e.g. vagus nerve stimulation, ketogenic diet) are already relatively well established in paediatric epilepsy. New pharmacological treatments include generational advances on existing AEDs and AEDs with novel modes of action, and non-AED pharmacological interventions, such as immunomodulation. Emerging technologies include novel approaches allowing the delivery of medicinal agents to specific areas of the brain, and 'closed-loop' experimental devices employing algorithms that allow treatment (e.g., electrical stimulation) to be targeted both spatially and temporally. Although in early stages of development, cell-based approaches (e.g., focal targeting of adenosine augmentation) and gene therapy may also provide new treatment choices in the future.
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Affiliation(s)
- J Helen Cross
- UCL-Institute of Child Health, Great Ormond Street Hospital for Children NHS Foundation Trust, London.
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Abstract
Epileptic encephalopathy is defined as a condition where the epileptic activity itself may contribute to the severe neurological and cognitive impairment seen, over and above that which would be expected from the underlying pathology alone. The epilepsy syndromes at high risk of this are a disparate group of conditions characterized by epileptic seizures that are difficult to treat and developmental delay. In this review, we discuss the ongoing debate regarding the significance of inter-ictal discharges and the impact of the seizures themselves on the cognitive delay or regression that is a common feature of these syndromes. The syndromes also differ in many ways and we provide a summary of the key features of the early-onset epileptic encephalopathies including Ohtahara and West syndromes in addition to later childhood-onset syndromes such as Lennox Gastaut and Doose syndromes. An understanding of the various severe epilepsy syndromes is vital to understanding the rationale for treatment. For example, the resolution of hypsarrhythmia in West syndrome is associated with an improvement in cognitive outcome and drives treatment choice, but the same cannot be applied to frequent inter-ictal discharges in Lennox Gastaut syndrome. We discuss the evidence base for treatment where it is available and describe current practice where it is not. For example, in West syndrome there is some evidence for preference of hormonal treatments over vigabatrin, although the choice and duration of hormonal treatment remains unclear. We describe the use of conventional and newer anti-epileptic medications in the various syndromes and discuss which medications should be avoided. Older possibly forgotten treatments such as sulthiame and potassium bromide also have a role in the severe epilepsies of childhood. We discuss hormonal treatment with particular focus on the treatment of West syndrome, continuous spike wave in slow wave sleep (CSWS)/electrical status epilepticus in slow wave sleep (ESES) and Landau Kleffner syndrome. The role of the ketogenic diet has in recent years come to the fore of the management of these severe epilepsies and we describe successful use in myoclonic astatic epilepsy, Lennox Gastaut syndrome and Dravet syndrome. It is important that resective epilepsy surgery is not ignored in the management of these children, particularly those with hemi-pathology who may present with ESES and respond well to hemispheric disconnection. Adjunctive and symptomatic surgical treatments such as vagal nerve stimulation and corpus callosotomy may improve seizure burden. Finally, it is vital that the identification and treatment of developmental, behavioural and psychiatric co-morbidities are not neglected and that a rational, holistic approach is taken to the management of epileptic encephalopathies.
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Affiliation(s)
- Amy McTague
- Neurosciences Unit, UCL-Institute of Child Health, 4/5 Long Yard, London, WC1N 3LU, UK.
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Abstract
Neonatal seizures can be classified as tonic, clonic, myoclonic, and subtle. A clinical diagnosis is not easy as seizures are usually subtle in neonates. In the majority of newborn infants seizures are subclinical. On the other hand, not all abnormal movements identified by clinicians as clinical seizures are accompanied by electroencephalographic seizure discharges in the EEG. Precise incidence is difficult to delineate and depends on study population and criteria used for diagnosis of seizures. Controversy exists as to whether neonatal seizures themselves cause damage to the developing brain, or if the damage is primarily due to the underlying cause of the seizures. As a result of this controversy there is ongoing discussion whether all seizures (both clinical and subclinical) should be treated. In addition, when (sub)clinical seizures are treated, there is no consensus about the most appropriate treatment for neonatal seizures and how to assess the efficacy of treatment. Current therapeutic options to treat neonatal seizures (i.e. primarily first-generation antiepileptic drugs [AEDs]) are relatively ineffective. In practice, phenobarbital still remains the drug of first choice for EEG confirmed or suspected seizures. Benzodiazepines are also used in (phenobarbital) refractory cases. Several (small) studies indicate that lidocaine is an effective drug for refractory seizures as second- or third-line treatment. Although data are scarce, some AEDs with a wide acceptance in adult and pediatric neurology practice are being used to treat neonatal seizures (i.e. second-generation AEDs). These drugs are chemically different from all first-generation AEDs and they have an effect on other pathways so they provide new pharmacological targets for controlling seizures in newborns. Levetiracetam, topiramate, felbamate, bumetanide, lamotrigine and vigabatrin are examples of these second-generation AEDs. There is an urgent need for prospective, randomized, controlled trials to assess the efficacy and safety of these second-generation AEDs in neonates. The aim of this review is to provide an overview of the current knowledge of diagnosis, the effect on brain injury, and the treatment of neonatal seizures.
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Abstract
There has been important progress in the identification of antiepileptic compounds and their indications in children over the past 15 years: their number has doubled and specific pediatric trials are being performed to document their effect according to seizures and syndromes as well as their tolerability in pediatrics. The improved understanding of pharmacokinetics and drug-drug interactions has helped to optimize treatment. Specific issues specific of infants have also been studied although new antiepileptic drugs are still dramatically lacking for this age group. Before reaching a syndromic diagnosis, the choice of a first- line agent goes to compounds with the largest range of efficacy and least identified risks. Subsequent choices are mainly based on the epilepsy syndrome and seizure type in addition to good clinical practice to determine dose, adverse effect profile, risk of aggravating seizures and drug interactions, clinician's experience, cultural habits, and availability of drugs. If there are several options, preference is given to the compound that exhibits the best risk/benefit ratio, or the most rapid titration when seizure frequency is the major issue. For new antiepileptic compounds, price is often a limiting factor in countries with poor insurance coverage. Third generation anti-epileptic drugs are emerging which also seem to be promising.
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Affiliation(s)
- C Chiron
- INSERM UMR663, Université Paris Descartes, Paris and CEA, France.
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Abstract
OPINION STATEMENT Solid organ transplantation is frequently complicated by a spectrum of seizure types, including single partial-onset or generalized tonic-clonic seizures, acute repetitive seizures or status epilepticus, and sometimes the evolution of symptomatic epilepsy. There is currently no specific evidence involving the transplant patient population to guide the selection, administration, or duration of antiepileptic drug (AED) therapy, so familiarity with clinical AED pharmacology and application of sound judgment are necessary for successful patient outcomes. An initial detailed search for symptomatic seizure etiologies, including metabolic, infectious, cerebrovascular, and calcineurin inhibitor treatment-related neurotoxic complications such as posterior reversible encephalopathy syndrome (PRES), is imperative, as underlying central nervous system disorders may impose additional serious risks to cerebral or general health if not promptly detected and appropriately treated. The mainstay for post-transplant seizure management is AED therapy directed toward the suspected seizure type. Unfavorable drug interactions could place the transplanted organ at risk, so choosing an AED with limited interaction potential is also crucial. When the transplanted organ is dysfunctional or vulnerable to rejection, AEDs without substantial hepatic metabolism are favored in post-liver transplant patients, whereas after renal transplantation, AEDs with predominantly renal elimination may require dosage adjustment to prevent adverse effects. Levetiracetam, gabapentin, pregabalin, and lacosamide are drugs of choice for treatment of partial-onset seizures in post-transplant patients given their efficacy spectrum, generally excellent tolerability, and lack of drug interaction potential. Levetiracetam is the drug of choice for primary generalized seizures in post-transplant patients. When intravenous drugs are necessary for acute seizure management, benzodiazepines and fosphenytoin are the traditional and best evidence-based options, although intravenous levetiracetam, valproate, and lacosamide are emerging options. Availability of several newer AEDs has greatly expanded the therapeutic armamentarium for safe and efficacious treatment of post-transplant seizures, but future prospective clinical trials and pharmacokinetic studies within this specific patient population are needed.
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Visual field and ocular safety during short-term vigabatrin treatment in cocaine abusers. Am J Ophthalmol 2012; 154:326-332.e2. [PMID: 22704138 DOI: 10.1016/j.ajo.2012.02.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 02/17/2012] [Accepted: 02/21/2012] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate the ocular safety of short-term vigabatrin treatment of cocaine abuse. DESIGN Multicenter, prospective, randomized, placebo-controlled, double-masked, parallel assignment study. METHODS Cocaine addicts were randomized to receive vigabatrin 3000 mg/day, cumulative dose 218 g (n = 92), or placebo (n = 94) for 12 weeks. Subjects underwent examination of visual acuity (ETDRS) and peripheral visual field (PVF) by Humphrey Field Analyzer (HFA) 60-4 program before and after treatment. Reliable PVF tests (fixation loss, false positive, and false negative <33%) for 103 subjects were included for the analysis. The threshold visual sensitivity (TVS) was analyzed by points, rings and zones. Main outcome measures included visual acuity decrease by 15 letters and/or significant PVF alteration, defined as 5 or more visual field location points having greater than or equal to 15 dB reduction in TVS or decline (≥33% loss) in posttreatment TVS for 1 or more rings. RESULTS Visual acuity decrease was detected in 1 eye of a subject receiving placebo and in none receiving vigabatrin. Posttreatment reduction in TVS more than 15 dB in 5 or more adjacent visual field location points combined with reduction in TVS greater than 33% in 1 or more of the rings was detected in 2 of 54 subjects (3.7%) from the vigabatrin group and in 1 of 49 subjects (2%) from the placebo group (P = .9, NS). None of the PVF changes were bilateral or concentric. CONCLUSIONS Short-term use of vigabatrin did not cause a decrease in visual acuity or significant peripheral visual field changes in cocaine abusers.
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Clayton LM, Devile M, Punte T, de Haan GJ, Sander JW, Acheson JF, Sisodiya SM. Patterns of peripapillary retinal nerve fiber layer thinning in vigabatrin-exposed individuals. Ophthalmology 2012; 119:2152-60. [PMID: 22853973 DOI: 10.1016/j.ophtha.2012.05.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 03/27/2012] [Accepted: 05/07/2012] [Indexed: 10/28/2022] Open
Abstract
PURPOSE To explore the relationship of peripapillary retinal nerve fiber layer (ppRNFL) thinning in individuals exposed to the antiepileptic drug vigabatrin with respect to 2 separate variables: cumulative vigabatrin exposure and severity of vigabatrin-associated visual field loss (VAVFL). DESIGN Cross-sectional observational study. PARTICIPANTS Subjects were older than 18 years, 129 with vigabatrin-treated epilepsy (vigabatrin-exposed group) and 87 individuals with epilepsy never treated with vigabatrin (nonexposed group). METHODS All subjects underwent ppRNFL imaging using spectral-domain optical coherence tomography. Eighty-four vigabatrin-exposed individuals underwent Goldmann kinetic perimetry. The visual field examined from the right eye was categorized as normal (n = 47), mildly abnormal (n = 18), or moderately to severely abnormal (n = 19). In 91 vigabatrin-exposed individuals, the cumulative vigabatrin exposure could be ascertained: 41 subjects received 1000 g or less, 23 subjects received more than 1000 g but equal to or less than 2500 g, 16 subjects received more than 2500 g but equal to or less than 5000 g or less, and 11 subjects received more than 5000 g. MAIN OUTCOME MEASURES Differences in ppRNFL thickness across the twelve 30° sectors: (1) among all nonexposed individuals and all vigabatrin-exposed individuals, (2) between each vigabatrin-exposed group, according to cumulative vigabatrin exposure, and the nonexposed group, (3) among different vigabatrin-exposed subjects grouped according to cumulative vigabatrin exposure, and (4) among vigabatrin-exposed subjects grouped according to severity of VAVFL. RESULTS The ppRNFL was significantly thinner in vigabatrin-exposed compared with nonexposed individuals in most 30° sectors (P<0.004). The temporal, temporal superior, and temporal inferior 30° sectors, as well as the nasal 30° sector, were not affected. There was a trend for increasing ppRNFL thinning with increasing cumulative vigabatrin exposure. The nasal-superior 30° sector was significantly thinner in group 1 (≤1000 g) compared with nonexposed individuals (P<0.05) and in vigabatrin-exposed individuals with normal visual fields compared with nonexposed individuals (P<0.05). CONCLUSIONS After vigabatrin exposure in individuals receiving cumulative doses of 1000 g or less or in the presence of normal visual fields, ppRNFL thinning in the nasal superior 30° sector may occur. With higher cumulative doses of vigabatrin exposure, additional ppRNFL thinning was observed. The temporal aspects of the ppRNFL are spared, even in individuals with large cumulative vigabatrin exposures and moderate or severe VAVFL.
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Affiliation(s)
- Lisa M Clayton
- Department of Clinical and Experimental Epilepsy, University College London Institute of Neurology, London, United Kingdom
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Abstract
Vigabatrin is an effective and well-tolerated antiepileptic drug (AED) for the treatment of refractory complex partial seizures (rCPS) and infantile spasms (IS), but its benefits must be evaluated in conjunction with its risk of retinopathy with the development of peripheral visual field defects (pVFDs). Vigabatrin should be considered for rCPS if a patient has failed appropriate trials of other AEDs or is not a suitable candidate for other AEDs, is not an optimal surgical candidate, and continues to experience debilitating effects from seizures. Vigabatrin is indicated as monotherapy for pediatric patients with IS. Its efficacy in achieving improved seizure control should be apparent within 12 weeks in patients with rCPS and within 2-4 weeks after attaining appropriate dosage for patients with IS. Because 12 weeks is well less than the known time of onset of visual defects, the risk of developing pVFDs may be minimized by discontinuing vigabatrin early during the course of therapy for patients with inadequate response. Appropriate vision screening is recommended at baseline, every 3 months during continued vigabatrin treatment, and at 3-6 months after discontinuation (if therapy has spanned more than a few months). If a pVFD is detected at any point and the decision is made to discontinue therapy, the pVFD is not likely to progress after discontinuation of vigabatrin. Although some patients will be at risk of retinopathy, vigabatrin is an appropriate treatment option for patients who achieve substantial clinical benefit, especially given the severe consequences of rCPS and uncontrolled IS. While retinopathy with the development of pVFDs is a serious adverse event, it is not life-threatening and its risk can be effectively managed.
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Affiliation(s)
- J M Pellock
- Department of Neurology, Virginia Commonwealth University, Richmond, VA 23298, USA.
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Moskowitz A, Hansen RM, Eklund SE, Fulton AB. Electroretinographic (ERG) responses in pediatric patients using vigabatrin. Doc Ophthalmol 2012; 124:197-209. [PMID: 22426576 DOI: 10.1007/s10633-012-9320-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 03/02/2012] [Indexed: 11/30/2022]
Abstract
The antiepileptic drug vigabatrin is known to cause retinal and visual dysfunction, particularly visual field defects, in some patients. Electroretinography (ERG) is used in an attempt to identify adverse effects of vigabatrin (VGB) in patients who are not candidates for conventional perimetry. We report data from 114 pediatric patients taking VGB referred for clinical evaluation; median age at test was 22.9 (2.4 to 266.1) months, and median duration of VGB use was 9.7 (0.3 to 140.7) months. Twenty-seven of them were tested longitudinally (3 to 12 ERG tests). ERG responses to full-field stimuli were recorded in scotopic and photopic conditions, and results were compared to responses from healthy control subjects. We found that abnormalities of photoreceptor and post-receptor ERG responses are frequent in these young patients. The most frequently abnormal scotopic parameter was post-receptor sensitivity, log σ, derived from the b-wave stimulus-response function; the most frequently abnormal photopic parameter was the implicit time of the OFF response (d-wave) to a long (150 ms) flash. Abnormal 30-Hz flicker response amplitude, previously reported to be a predictor of visual field loss, occurred infrequently. For the group as a whole, none of the ERG parameters changed significantly with increasing duration of VGB use. Four of the 27 patients tested longitudinally showed systematic worsening of log σ with duration of VGB use. In a subset of patients who underwent perimetry (N = 39), there was no significant association of any ERG parameter with visual field defects. We cannot determine whether the ERG abnormalities we found were due solely to the effects of VGB. We caution against over-reliance on the ERG to monitor pediatric patients for VGB toxicity and recommend further development of a reliable test of peripheral vision to supplant ERG testing.
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Affiliation(s)
- Anne Moskowitz
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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Greiner HM, Lynch ER, Fordyce S, Agricola K, Tudor C, Franz DN, Krueger DA. Vigabatrin for childhood partial-onset epilepsies. Pediatr Neurol 2012; 46:83-8. [PMID: 22264701 DOI: 10.1016/j.pediatrneurol.2011.11.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 11/29/2011] [Indexed: 11/16/2022]
Abstract
To determine vigabatrin's effectiveness and the prevalence of symptomatic visual impairment (i.e., impairment affecting the ability to perform everyday activities) associated with its therapy in pediatric epilepsy, we retrospectively reviewed medical records of 156 patients receiving vigabatrin at Cincinnati Children's Medical Center from 1998-2010. In addition to demographics and vigabatrin dosing information, data included seizure type/frequency at presentation and subsequent follow-up. Of 156 patients, we excluded 35 because their medical records were insufficient to permit verification of the exact duration or timing of vigabatrin treatment. To evaluate efficacy (n = 121/135), we used a 5-point scale (0-4) to compare seizure frequency at several time points. To evaluate visual impairment (n = 63), we reviewed serial ophthalmologic evaluations at baseline and during treatment for patients in whom they were clinically indicated. Mean age at treatment initiation was 1.8 years (range, 0.1-29.2 years). Treatment duration ranged from 0.7-101.0 months, with an estimated average daily dose of 79 mg/kg/day. Tuberous sclerosis complex was the commonest seizure etiology (83%). Partial-onset seizure, alone or with infantile spasms, was the commonest seizure type (84%). Seizure frequency decreased from 3.7 ± 0.6 S.D. at baseline to 1.8 ± 1.7 S.D. at 6 months (P < 0.001). Responses to vigabatrin did not differ by tuberous sclerosis complex or nontuberous sclerosis complex etiology, and were sustained for 5 years. Sixty-three patients (∼50% of all patients evaluated) underwent clinically indicated ophthalmologic assessments during the review period. In our clinical judgment, no cases of clinically relevant vigabatrin-associated visual impairment occurred. Vigabatrin was effective for refractory childhood partial-onset epilepsy, and was not associated with symptomatic vision loss.
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Affiliation(s)
- Hansel M Greiner
- Division of Neurology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA
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Silverman RB. The 2011 E. B. Hershberg award for important discoveries in medicinally active substances: (1S,3S)-3-amino-4-difluoromethylenyl-1-cyclopentanoic acid (CPP-115), a GABA aminotransferase inactivator and new treatment for drug addiction and infantile spasms. J Med Chem 2012; 55:567-75. [PMID: 22168767 PMCID: PMC3266980 DOI: 10.1021/jm201650r] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Richard B Silverman
- Department of Chemistry, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208-3113, United States.
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Pan Y, Gerasimov MR, Kvist T, Wellendorph P, Madsen KK, Pera E, Lee H, Schousboe A, Chebib M, Bräuner-Osborne H, Craft CM, Brodie JD, Schiffer WK, Dewey SL, Miller SR, Silverman RB. (1S, 3S)-3-amino-4-difluoromethylenyl-1-cyclopentanoic acid (CPP-115), a potent γ-aminobutyric acid aminotransferase inactivator for the treatment of cocaine addiction. J Med Chem 2011; 55:357-66. [PMID: 22128851 DOI: 10.1021/jm201231w] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Vigabatrin, a GABA aminotransferase (GABA-AT) inactivator, is used to treat infantile spasms and refractory complex partial seizures and is in clinical trials to treat addiction. We evaluated a novel GABA-AT inactivator (1S, 3S)-3-amino-4-difluoromethylenyl-1-cyclopentanoic acid (CPP-115, compound 1) and observed that it does not exhibit other GABAergic or off-target activities and is rapidly and completely orally absorbed and eliminated. By use of in vivo microdialysis techniques in freely moving rats and microPET imaging techniques, 1 produced similar inhibition of cocaine-induced increases in extracellular dopamine and in synaptic dopamine in the nucleus accumbens at (1)/(300) to (1)/(600) the dose of vigabatrin. It also blocks expression of cocaine-induced conditioned place preference at a dose (1)/(300) that of vigabatrin. Electroretinographic (ERG) responses in rats treated with 1, at doses 20-40 times higher than those needed to treat addiction in rats, exhibited reductions in ERG responses, which were less than the reductions observed in rats treated with vigabatrin at the same dose needed to treat addiction in rats. In conclusion, 1 can be administered at significantly lower doses than vigabatrin, which suggests a potential new treatment for addiction with a significantly reduced risk of visual field defects.
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Affiliation(s)
- Yue Pan
- Department of Chemistry, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208-3113, United States
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Pellock JM, Faught E, Sergott RC, Shields WD, Burkhart GA, Krauss GL, Foroozan R, Wesche DL, Weinberg MA. Registry initiated to characterize vision loss associated with vigabatrin therapy. Epilepsy Behav 2011; 22:710-7. [PMID: 21978471 DOI: 10.1016/j.yebeh.2011.08.034] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 08/25/2011] [Accepted: 08/26/2011] [Indexed: 10/16/2022]
Abstract
The vigabatrin patient registry was implemented in August 2009 in conjunction with Food and Drug Administration approval of vigabatrin. All US vigabatrin-treated patients must enroll in the registry. Data on prescriber specialty/location, patient demographics, and clinical characteristics are collected. Benefit-risk assessments are required early in the course of therapy. Vision assessments are required at baseline (≤4 weeks after therapy initiation), every 3 months during therapy, and 3 to 6 months after discontinuation. As of February 1, 2011, 2473 patients (1500 with infantile spasms, 846 with refractory complex partial seizures, 120 with other diagnoses) had enrolled; 30.4% were previously exposed to vigabatrin. Kaplan-Meier analysis of time in registry indicated that 83 and 97% of all enrolled patients with refractory complex partial seizures and infantile spasms remained beyond 3 and 1 month, respectively. The ongoing registry will provide visual status and other information on vigabatrin-treated patients for both the infantile spasm and refractory complex partial seizure indications.
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Abstract
Vigabatrin is an irreversible inhibitor of γ-aminobutyric acid (GABA) transaminase. It is effective as adjunctive therapy for adult patients with refractory complex partial seizures (rCPS) who have inadequately responded to several alternative treatments and as monotherapy for children aged 1 month to 2 years with infantile spasms. The well-documented safety profile of vigabatrin includes risk of retinopathy characterized by irreversible, bilateral, concentric peripheral visual field constriction. Thus, monitoring of visual function to understand the occurrence and manage the potential consequences of peripheral visual field defects (pVFDs) is now required for all patients who receive vigabatrin. However, screening for pVFDs for patients with epilepsy was conducted only after the association between vigabatrin and pVFDs was established. We examined the potential association between pVFDs and epilepsy in vigabatrin-naïve patients and attempted to identify confounding factors (e.g., concomitant medications, method of vision assessment) to more accurately delineate the prevalence of pVFDs directly associated with vigabatrin. Results of a prospective cohort study as well as several case series and case reports suggest that bilateral visual field constriction is not restricted to patients exposed to vigabatrin but has also been detected, although much less frequently, in vigabatrin-naïve patients with epilepsy, including those who received treatment with other GABAergic antiepileptic therapy. We also reviewed published data suggesting an association between vigabatrin-associated retinal toxicity and taurine deficiency, as well as the potential role of taurine in the prevention of this retinopathy.
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Affiliation(s)
- G T Plant
- Department of Neuro-Ophthalmology, National Hospital for Neurology and Neurosurgery, London, UK.
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Cavalleri GL, McCormack M, Alhusaini S, Chaila E, Delanty N. Pharmacogenomics and epilepsy: the road ahead. Pharmacogenomics 2011; 12:1429-47. [DOI: 10.2217/pgs.11.85] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Epilepsy is one of the most common, serious neurological disorders, affecting an estimated 50 million people worldwide. The condition is typically treated using antiepileptic drugs of which there are 16 in widespread use. However, there are many different syndrome and seizure types within epilepsy and information guiding clinicians on the most effective drug and dose for individual patients is lacking. Further, all of the antiepileptic drugs have associated adverse reactions, some of which are severe and life-threatening. Here, we review the pharmacogenomic work to date in the context of these issues and comment on key aspects of study design that are required to speed up the identification of clinically relevant genetic factors.
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Affiliation(s)
| | - Mark McCormack
- Molecular & Cellular Therapeutics, the Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Saud Alhusaini
- Molecular & Cellular Therapeutics, the Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Elijah Chaila
- The Division of Neurology, Beaumont Hospital, Dublin, Ireland
| | - Norman Delanty
- Molecular & Cellular Therapeutics, the Royal College of Surgeons in Ireland, Dublin, Ireland
- The Division of Neurology, Beaumont Hospital, Dublin, Ireland
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Clayton LM, Dévilé M, Punte T, Kallis C, de Haan GJ, Sander JW, Acheson J, Sisodiya SM. Retinal nerve fiber layer thickness in vigabatrin-exposed patients. Ann Neurol 2011; 69:845-54. [PMID: 21246602 DOI: 10.1002/ana.22266] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Accepted: 09/10/2010] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Vigabatrin-associated visual field loss (VAVFL) occurs in 25 to 50% of exposed patients and is routinely monitored using perimetry, which has inherent limitations. Using optical coherence tomography (OCT), retinal nerve fiber layer (RNFL) thinning has been described in a small number of vigabatrin-exposed patients. We explored the relationship between RNFL thickness and visual field size, to determine whether OCT is a suitable tool to use in patients exposed to vigabatrin. METHODS Two hundred one vigabatrin-exposed subjects with epilepsy, divided into 2 groups, and 90 healthy controls participated. Visual fields were obtained using Goldmann kinetic perimetry and quantified using mean radial degrees (MRD). RNFL imaging was performed using either spectral-domain (Group 1) or time-domain (Group 2) OCT. RESULTS Thirty-nine of 201 (19.4%) patients were unable to perform perimetry. Thirteen (6.5%) patients were unable to perform OCT. A total of 51.6% of patients showed VAVFL. Average RNFL thickness was significantly thinner in patients (77.9 μm) compared to healthy controls (93.6 μm) (p < 0.001). There was a strong correlation between MRD and average RNFL thickness for Group 1 (r = 0.768, p < 0.001) and Group 2 (r = 0.814, p < 0.001). OCT RNFL imaging showed high repeatability. INTERPRETATION OCT provides a useful tool to assess people exposed to vigabatrin, and can provide an accurate estimate of the extent of visual field loss in the absence of a reliable direct measure of the visual field. The strong linear relationship found between RNFL thickness and visual field size provides some evidence that irreversible VAVFL may be related to loss of retinal ganglion cell axons.
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Affiliation(s)
- Lisa M Clayton
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, United Kingdom
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Sergott RC, Bittman RM, Christen EM, Sagar SM. Vigabatrin-induced peripheral visual field defects in patients with refractory partial epilepsy. Epilepsy Res 2010; 92:170-6. [DOI: 10.1016/j.eplepsyres.2010.09.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 08/27/2010] [Accepted: 09/13/2010] [Indexed: 11/25/2022]
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Maguire MJ, Hemming K, Wild JM, Hutton JL, Marson AG. Prevalence of visual field loss following exposure to vigabatrin therapy: A systematic review. Epilepsia 2010; 51:2423-31. [DOI: 10.1111/j.1528-1167.2010.02772.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Current world literature. Curr Opin Ophthalmol 2010; 21:495-501. [PMID: 20948381 DOI: 10.1097/icu.0b013e3283402a34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Current awareness: Pharmacoepidemiology and drug safety. Pharmacoepidemiol Drug Saf 2010. [DOI: 10.1002/pds.1851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
The newer antiepileptic drugs (AEDs) provide more therapeutic options and overall improved safety and tolerability for patients. To provide the best care, physicians must be familiar with the latest tolerability and safety data. This is particularly true in children, given there are relatively fewer studies examining the effects of AEDs in children compared with adults. Since we now have significant paediatric literature on each of these agents, we provide a comprehensive and current literature review of the newer AEDs, focusing on safety and tolerability data in children and adolescents. Because the safety profiles in children differ from those in adults, familiarity with this literature is important for child neurologists and other paediatric caregivers. We have organized the data by organ system for each AED for easier reference.
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Affiliation(s)
- Dean P Sarco
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Children's Hospital Boston, Boston, Massachusetts, USA.
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