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Elmorsi RM, Kabel AM, El Saadany AA, Abou El-Seoud SH. The protective effects of topiramate and spirulina against doxorubicin-induced cardiotoxicity in rats. Hum Exp Toxicol 2023; 42:9603271231198624. [PMID: 37644674 DOI: 10.1177/09603271231198624] [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: 08/31/2023]
Abstract
Doxorubicin (DOX) is a widely used chemotherapy drug that can cause significant cardiotoxicity, limiting its clinical application. This study aimed to investigate the potential protective effects of topiramate (TPM) and spirulina (SP), either alone or in combination, in preventing DOX-induced cardiotoxicity. Adult Sprague Dawley rats were divided into five groups, including a normal control group and groups receiving DOX alone, DOX with TPM, DOX with SP, or DOX with a combination of TPM and SP. Cardiotoxicity was induced by administering DOX intraperitoneally at a cumulative dose of 16 mg/kg over 4 weeks. TPM and/or SP administration started 1 week before DOX treatment and continued for 35 days. Body weight, serum markers of cardiac damage, oxidative stress and inflammatory parameters were assessed. Histopathological and immunohistochemical examinations were performed on cardiac tissues. Results showed that TPM and SP monotherapy led to significant improvements in serum levels of cardiac markers, decreased oxidative stress, reduced fibrosis-related growth factor levels, increased antioxidant levels, and improved histopathological features. SP demonstrated more prominent effects in comparison to TPM, and the combination of TPM and SP exhibited even more pronounced effects. In conclusion, TPM and SP, either alone or in combination, hold promise as therapeutic interventions for mitigating DOX-induced cardiotoxicity.
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Affiliation(s)
- Radwa M Elmorsi
- Department of Pharmacology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Ahmed M Kabel
- Department of Pharmacology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Amira A El Saadany
- Department of Pharmacology, Faculty of Medicine, Tanta University, Tanta, Egypt
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2
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Tippayachai P, Leelakanok N, Methaneethorn J. Significant predictors for topiramate pharmacokinetics: a systematic review of population pharmacokinetic studies. JOURNAL OF PHARMACY PRACTICE AND RESEARCH 2022. [DOI: 10.1002/jppr.1787] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Patinee Tippayachai
- Department of Pharmacy Practice Faculty of Pharmaceutical Sciences Naresuan University Phitsanulok Thailand
| | - Nattawut Leelakanok
- Department of Clinical Pharmacy Faculty of Pharmaceutical Sciences Burapha University Chonburi Thailand
| | - Janthima Methaneethorn
- Department of Pharmacy Practice Faculty of Pharmaceutical Sciences Naresuan University Phitsanulok Thailand
- Center of Excellence for Environmental Health and Toxicology Naresuan University Phitsanulok Thailand
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Alqarni MH, Shakeel F, Mahdi WA, Foudah AI, Aljarba TM, Alshehri S, Ghoneim MM, Alam P. A Greener Stability-Indicating High-Performance Thin-Layer Chromatography Approach for the Estimation of Topiramate. MATERIALS 2022; 15:ma15051731. [PMID: 35268960 PMCID: PMC8911037 DOI: 10.3390/ma15051731] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 02/20/2022] [Accepted: 02/22/2022] [Indexed: 12/23/2022]
Abstract
Despite various reported analytical methods for topiramate (TPM) analysis, greener analytical approaches are scarce in literature. As a consequence, the objective of the current research is to design a normal-phase stability-indicating high-performance thin-layer chromatography (SI-HPTLC) methodology for TPM analysis in marketed tablet dosage forms that is rapid, sensitive, and greener. TPM was derivatized densitometrically and analyzed at 423 nm in visible mode with anisaldehyde-sulfuric acid as the derivatizing agent. The greener SI-HPTLC technique was linear in the 30–1200 ng band−1 range. In addition, the suggested SI-HPTLC methodology for TPM analysis was simple, rapid, cheaper, precise, robust, sensitive, and environmentally friendly. The greener SI-HPTLC method was able to detect TPM along with its degradation products under acid, base, and oxidative degradation conditions. However, no TPM degradation was recorded under thermal and photolytic stress conditions. TPM contents in commercial tablet dosage forms were recorded as 99.14%. Using 12 different principles of green analytical chemistry, the overall analytical GREEnness (AGREE) score for the greener SI-HPTLC method was calculated to be 0.76, confirming the proposed normal-phase SI-HPTLC method’s good greener nature. Overall, these results demonstrated that the suggested SI-HPTLC technique for TPM measurement in pharmaceutical products was reliable and selective.
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Affiliation(s)
- Mohammed H. Alqarni
- Department of Pharmacognosy, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia; (M.H.A.); (A.I.F.); (T.M.A.)
| | - Faiyaz Shakeel
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia; (F.S.); (W.A.M.); (S.A.)
| | - Wael A. Mahdi
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia; (F.S.); (W.A.M.); (S.A.)
| | - Ahmed I. Foudah
- Department of Pharmacognosy, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia; (M.H.A.); (A.I.F.); (T.M.A.)
| | - Tariq M. Aljarba
- Department of Pharmacognosy, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia; (M.H.A.); (A.I.F.); (T.M.A.)
| | - Sultan Alshehri
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia; (F.S.); (W.A.M.); (S.A.)
| | - Mohammed M. Ghoneim
- Department of Pharmacy Practice, College of Pharmacy, AlMaarefa University, Ad Diriyah 13713, Saudi Arabia;
| | - Prawez Alam
- Department of Pharmacognosy, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia; (M.H.A.); (A.I.F.); (T.M.A.)
- Correspondence: or
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Topiramate Blood Levels During Polytherapy for Epilepsy in Children. Am J Ther 2019; 26:e18-e24. [PMID: 27875371 DOI: 10.1097/mjt.0000000000000529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The therapeutic range of topiramate (TPM) blood level is not set because the efficacy and safety are not considered to be related to the level. However, the therapeutic target without side effects is necessary, so the optimal range of TPM blood level was analyzed in this study. STUDY QUESTION This study was conducted to evaluate the efficacy of TPM over 2 years and the utility of measuring blood levels of TPM during the follow-up of epileptic patients. STUDY DESIGN Thirty patients (18 males, 12 females; age range, 6 months-15 years) were treated with TPM for epilepsy. The initial dosage of TPM was 1-3 mg·kg·d. If the effect proved insufficient after 2 weeks, the dosage was increased to 4-9 mg·kg·d. MEASURES AND OUTCOMES Blood levels of TPM were measured by liquid chromatography-tandem mass spectrometry at 1, 6, 12, and 24 months after levels reached steady state. The efficacy of TPM was evaluated by the reduction in epileptic seizure rate (RR) at the time of blood sampling. Statistical analysis was performed using the Mann-Whitney U test. RESULTS A positive correlation was seen between blood levels and maintenance dosages, but no correlation was observed between blood levels and RR. Any significant difference was not identified in TPM levels between the effective group (RR ≥50%) and the ineffective group (RR <50%; P = 0.159). In the subgroup of patients who did not use valproic acid, a significant difference in TPM levels was apparent between the effective and ineffective groups (P = 0.029). The optimal range of TPM was advocated 3.5-5.0 μg/mL. The optimal range was set, so that ranges did not overlap between the effective and ineffective groups. No patients experienced any side effects. CONCLUSIONS Measuring blood levels of TPM based on the classification of concomitant drugs and adjusting the dosage to reach the optimal range were recommended.
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Greco R, Demartini C, Zanaboni AM, Tassorelli C. Chronic and intermittent administration of systemic nitroglycerin in the rat induces an increase in the gene expression of CGRP in central areas: potential contribution to pain processing. J Headache Pain 2018; 19:51. [PMID: 30003352 PMCID: PMC6043463 DOI: 10.1186/s10194-018-0879-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 07/02/2018] [Indexed: 01/08/2023] Open
Abstract
Background Calcitonin gene related peptide (CGRP) is a key neuropeptide involved in the activation of the trigeminovascular system and it is likely related to migraine chronification. Here, we investigated the role of CGRP in an animal model that mimics the chronic migraine condition via repeated and intermittent nitroglycerin (NTG) administration. We also evaluated the modulatory effect of topiramate on this experimental paradigm. Male Sprague-Dawley rats were injected with NTG (5 mg/kg, i.p.) or vehicle, every 2 days over a 9-day period (5 total injections). A group of animals was injected with topiramate (30 mg/kg, i.p.) or saline every day for 9 days. Twenty-four hours after the last administration of NTG or vehicle, animals underwent tail flick test and orofacial Von Frey test. Rats were subsequently sacrificed to evaluate c-Fos and CGRP gene expression in medulla-pons region, cervical spinal cord and trigeminal ganglia. Results NTG administration induced spinal hyperalgesia and orofacial allodynia, together with a significant increase in the expression of CGRP and c-Fos genes in trigeminal ganglia and central areas. Topiramate treatment prevented NTG-induced changes by reversing NTG-induced hyperalgesia and allodynia, and inhibiting CGRP and c-Fos gene expression in all areas evaluated. Conclusions These findings point to the role of CGRP in the processes underlying migraine chronification and suggest a possible interaction with gamma-aminobutyrate (GABA) and glutamate transmission to induce/maintain central sensitization and to contribute to the dysregulation of descending pain system involved in chronic migraine.
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Affiliation(s)
- Rosaria Greco
- Laboratory of Neurophysiology of Integrative Autonomic Systems, Headache Science Centre, IRCCS Mondino Foundation, Pavia, Italy.
| | - Chiara Demartini
- Laboratory of Neurophysiology of Integrative Autonomic Systems, Headache Science Centre, IRCCS Mondino Foundation, Pavia, Italy
| | - Anna Maria Zanaboni
- Laboratory of Neurophysiology of Integrative Autonomic Systems, Headache Science Centre, IRCCS Mondino Foundation, Pavia, Italy.,Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Cristina Tassorelli
- Laboratory of Neurophysiology of Integrative Autonomic Systems, Headache Science Centre, IRCCS Mondino Foundation, Pavia, Italy.,Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
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Fan HC, Lee HS, Chang KP, Lee YY, Lai HC, Hung PL, Lee HF, Chi CS. The Impact of Anti-Epileptic Drugs on Growth and Bone Metabolism. Int J Mol Sci 2016; 17:E1242. [PMID: 27490534 PMCID: PMC5000640 DOI: 10.3390/ijms17081242] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/20/2016] [Accepted: 07/28/2016] [Indexed: 12/13/2022] Open
Abstract
Epilepsy is a common neurological disorder worldwide and anti-epileptic drugs (AEDs) are always the first choice for treatment. However, more than 50% of patients with epilepsy who take AEDs have reported bone abnormalities. Cytochrome P450 (CYP450) isoenzymes are induced by AEDs, especially the classical AEDs, such as benzodiazepines (BZDs), carbamazepine (CBZ), phenytoin (PT), phenobarbital (PB), and valproic acid (VPA). The induction of CYP450 isoenzymes may cause vitamin D deficiency, hypocalcemia, increased fracture risks, and altered bone turnover, leading to impaired bone mineral density (BMD). Newer AEDs, such as levetiracetam (LEV), oxcarbazepine (OXC), lamotrigine (LTG), topiramate (TPM), gabapentin (GP), and vigabatrin (VB) have broader spectra, and are safer and better tolerated than the classical AEDs. The effects of AEDs on bone health are controversial. This review focuses on the impact of AEDs on growth and bone metabolism and emphasizes the need for caution and timely withdrawal of these medications to avoid serious disabilities.
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Affiliation(s)
- Hueng-Chuen Fan
- Department of Pediatrics, Tungs' Taichung Metroharbor Hospital, Wuchi, 435 Taichung, Taiwan.
- Department of Nursing, Jen-Teh Junior College of Medicine, Nursing and Management, 356 Miaoli, Taiwan.
| | - Herng-Shen Lee
- Department of Pathology and Laboratory Medicine, Kaohsiung Veterans General Hospital, 813 Kaohsiung, Taiwan.
| | - Kai-Ping Chang
- Department of Pediatrics, Taipei Veterans General Hospital, 112 Taipei, Taiwan.
| | - Yi-Yen Lee
- Division of Pediatric Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, 112 Taipei, Taiwan.
- Faculty of Medicine, National Yang-Ming University, 112 Taipei, Taiwan.
| | - Hsin-Chuan Lai
- Department of Pediatrics, Tungs' Taichung Metroharbor Hospital, Wuchi, 435 Taichung, Taiwan.
- Department of Nursing, Jen-Teh Junior College of Medicine, Nursing and Management, 356 Miaoli, Taiwan.
| | - Pi-Lien Hung
- Department of Pediatrics, Kaohsiung Chang Gung Medical Center, 833 Kaohsiung, Taiwan.
| | - Hsiu-Fen Lee
- Department of Pediatrics, Taichung Veterans General Hospital, 407 Taichung, Taiwan.
| | - Ching-Shiang Chi
- Department of Pediatrics, Tungs' Taichung Metroharbor Hospital, Wuchi, 435 Taichung, Taiwan.
- Department of Nursing, Jen-Teh Junior College of Medicine, Nursing and Management, 356 Miaoli, Taiwan.
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Abstract
Movement disorders can be challenging to manage and often use a specific set of medications. Because it is a complex and broad field within neurology, many providers are unfamiliar with the classes of medications. This paper details medications used for specific conditions, explains why these medications are helpful, and shares pearls and pitfalls related to each agent, focusing on parameters such as dose titration, side effect profiles, and specific drug-drug interactions and challenges. We focus on the most commonly encountered movement disorders, including essential tremor, Parkinson's disease, rapid eye movement sleep behavior disorder, and restless leg syndrome.
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Affiliation(s)
- Anthony Julius
- VA Puget Sound, University of Washington Medical Center, 1660 South Columbian Way, Seattle, WA 98108, USA
| | - Katelan Longfellow
- VA Puget Sound, University of Washington Medical Center, 1660 South Columbian Way, Seattle, WA 98108, USA.
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Affiliation(s)
- N A Uvais
- Department of Psychiatry, Iqraa International Hospital and Research Centre, Calicut, Kerala, India
| | - V S Sreeraj
- Department of Psychiatry, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, Karnataka, India
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Bae EK, Lee J, Shin JW, Moon J, Lee KJ, Shin YW, Kim TJ, Shin D, Jang IJ, Lee SK. Factors influencing topiramate clearance in adult patients with epilepsy: A population pharmacokinetic analysis. Seizure 2016; 37:8-12. [DOI: 10.1016/j.seizure.2016.02.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 02/02/2016] [Accepted: 02/04/2016] [Indexed: 01/08/2023] Open
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Meseeha MG, Attia MN, Kolade VO. Topiramate as a rare cause of reversible Fanconi syndrome and acute kidney injury: a case report and literature review. J Community Hosp Intern Med Perspect 2016; 6:30510. [PMID: 26908388 PMCID: PMC4763558 DOI: 10.3402/jchimp.v6.30510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 12/29/2015] [Accepted: 12/31/2015] [Indexed: 11/14/2022] Open
Abstract
Topiramate (TPM) is a sulfa-derivative monosaccharide that has been used for multiple indications in the last several years. We describe a 53-year-old woman with known chronic kidney disease stage 2 and baseline creatinine of 1 mg/dL who developed acute kidney injury and proximal renal tubular dysfunction while on TPM for depression. The Naranjo Adverse Drug Reaction Probability Scale indicated a probable relationship (score of 6) between TPM and acute kidney injury as well as proximal tubular dysfunction; these renal conditions resolved on withdrawal of TPM. To our knowledge, this is the first report of such a scenario. Patients receiving TPM therapy should be closely monitored for evidence of kidney dysfunction and electrolyte abnormalities.
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Affiliation(s)
| | - Maximos N Attia
- Department of Family Medicine, Guthrie Clinic, Sayre, PA, USA
| | - Victor O Kolade
- Department of Internal Medicine, Guthrie Clinic, Sayre, PA, USA
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Bhatti SFM, De Risio L, Muñana K, Penderis J, Stein VM, Tipold A, Berendt M, Farquhar RG, Fischer A, Long S, Löscher W, Mandigers PJJ, Matiasek K, Pakozdy A, Patterson EE, Platt S, Podell M, Potschka H, Rusbridge C, Volk HA. International Veterinary Epilepsy Task Force consensus proposal: medical treatment of canine epilepsy in Europe. BMC Vet Res 2015; 11:176. [PMID: 26316233 PMCID: PMC4552371 DOI: 10.1186/s12917-015-0464-z] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 06/29/2015] [Indexed: 12/14/2022] Open
Abstract
In Europe, the number of antiepileptic drugs (AEDs) licensed for dogs has grown considerably over the last years. Nevertheless, the same questions remain, which include, 1) when to start treatment, 2) which drug is best used initially, 3) which adjunctive AED can be advised if treatment with the initial drug is unsatisfactory, and 4) when treatment changes should be considered. In this consensus proposal, an overview is given on the aim of AED treatment, when to start long-term treatment in canine epilepsy and which veterinary AEDs are currently in use for dogs. The consensus proposal for drug treatment protocols, 1) is based on current published evidence-based literature, 2) considers the current legal framework of the cascade regulation for the prescription of veterinary drugs in Europe, and 3) reflects the authors' experience. With this paper it is aimed to provide a consensus for the management of canine idiopathic epilepsy. Furthermore, for the management of structural epilepsy AEDs are inevitable in addition to treating the underlying cause, if possible.
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Affiliation(s)
- Sofie F M Bhatti
- Department of Small Animal Medicine and Clinical Biology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium.
| | - Luisa De Risio
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, CB8 7UU, Suffolk, United Kingdom.
| | - Karen Muñana
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1052 William Moore Drive, Raleigh, NC, 27607, USA.
| | - Jacques Penderis
- Vet Extra Neurology, Broadleys Veterinary Hospital, Craig Leith Road, Stirling, FK7 7LE, Stirlingshire, United Kingdom.
| | - Veronika M Stein
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Bünteweg 9, 30559, Hannover, Germany.
| | - Andrea Tipold
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Bünteweg 9, 30559, Hannover, Germany.
| | - Mette Berendt
- Department of Veterinary and Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.
| | - Robyn G Farquhar
- Fernside Veterinary Centre, 205 Shenley Road, Borehamwood, SG9 0TH, Hertfordshire, United Kingdom.
| | - Andrea Fischer
- Clinical Veterinary Medicine, Ludwig-Maximillians-University, Veterinärstr. 13, 80539, Munich, Germany.
| | - Sam Long
- University of Melbourne, 250 Princes Highway, Weibee, 3015, VIC, Australia.
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Bünteweg 17, 30559, Hannover, Germany.
| | - Paul J J Mandigers
- Department of Clinical Sciences of Companion Animals, Utrecht University, Yalelaan 108, 3583 CM, Utrecht, The Netherlands.
| | - Kaspar Matiasek
- Section of Clinical & Comparative Neuropathology, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University, Veterinärstr. 13, 80539, Munich, Germany.
| | - Akos Pakozdy
- Clinical Unit of Internal Medicine Small Animals, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.
| | - Edward E Patterson
- University of Minnesota College of Veterinary Medicine, D426 Veterinary Medical Center, 1352 Boyd Avenue, St. Paul, MN, 55108, USA.
| | - Simon Platt
- College of Veterinary Medicine, University of Georgia, 501 DW Brooks Drive, Athens, GA, 30602, USA.
| | - Michael Podell
- Chicago Veterinary Neurology and Neurosurgery, 3123 N. Clybourn Avenue, Chicago, IL, 60618, USA.
| | - Heidrun Potschka
- Department of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximillians-University, Königinstr. 16, 80539, Munich, Germany.
| | - Clare Rusbridge
- Fitzpatrick Referrals, Halfway Lane, Eashing, Godalming, GU7 2QQ, Surrey, United Kingdom.
- School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, GU2 7TE, Surrey, United Kingdom.
| | - Holger A Volk
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, AL9 7TA, Hertfordshire, UK.
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Manitpisitkul P, Curtin CR, Shalayda K, Wang SS, Ford L, Heald D. Pharmacokinetic interactions between topiramate and pioglitazone and metformin. Epilepsy Res 2014; 108:1519-32. [PMID: 25219351 DOI: 10.1016/j.eplepsyres.2014.08.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 07/14/2014] [Accepted: 08/21/2014] [Indexed: 01/28/2023]
Abstract
OBJECTIVE To investigate potential drug-drug interactions between topiramate and metformin and pioglitazone at steady state. METHODS Two open-label studies were performed in healthy adult men and women. In Study 1, eligible participants were given metformin alone for 3 days (500 mg twice daily [BID]) followed by concomitant metformin and topiramate (titrated to 100mg BID) from days 4 to 10. In Study 2, eligible participants were randomly assigned to treatment with pioglitazone 30 mg once daily (QD) alone for 8 days followed by concomitant pioglitazone and topiramate (titrated to 96 mg BID) from days 9 to 22 (Group 1) or to topiramate (titrated to 96 mg BID) alone for 11 days followed by concomitant pioglitazone 30 mg QD and topiramate 96 mg BID from days 12 to 22 (Group 2). An analysis of variance was used to evaluate differences in pharmacokinetics with and without concomitant treatment; 90% confidence intervals (CI) for the ratio of the geometric least squares mean (LSM) estimates for maximum plasma concentration (Cmax), area under concentration-time curve for dosing interval (AUC12 or AUC24), and oral clearance (CL/F) with and without concomitant treatment were used to assess a drug interaction. RESULTS A comparison to historical data suggested a modest increase in topiramate oral clearance when given concomitantly with metformin. Coadministration with topiramate reduced metformin oral clearance at steady state, resulting in a modest increase in systemic metformin exposure. Geometric LSM ratios and 90% CI for metformin CL/F and AUC12 were 80% (75%, 85%) and 125% (117%, 134%), respectively. Pioglitazone had no effect on topiramate pharmacokinetics at steady state. Concomitant topiramate resulted in decreased systemic exposure to pioglitazone and its active metabolites, with geometric LSM ratios and 90% CI for AUC24 of 85.0% (75.7%, 95.6%) for pioglitazone, 40.5% (36.8%, 44.6%) for M-III, and 83.8% (76.1%, 91.2%) for M-IV, respectively. This effect appeared more pronounced in women than in men. Coadministration of topiramate with metformin or pioglitazone was generally well tolerated by healthy participants in these studies. CONCLUSIONS A modest increase in metformin exposure and decrease in topiramate exposure was observed at steady state following coadministration of metformin 500 mg BID and topiramate 100mg BID. The clinical significance of the observed interaction is unclear but is not likely to require a dose adjustment of either agent. Pioglitazone 30 mg QD did not affect the pharmacokinetics of topiramate at steady state, while coadministration of topiramate 96 mg BID with pioglitazone decreased steady-state systemic exposure to pioglitazone, M-III, and M-IV. While the clinical consequence of this interaction is unknown, careful attention should be given to the routine monitoring for adequate glycemic control of patients receiving this concomitant therapy. Concomitant administration of topiramate with metformin or pioglitazone was generally well tolerated and no new safety concerns were observed.
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Affiliation(s)
| | | | | | | | - Lisa Ford
- Janssen Research & Development, LLC, Raritan, NJ, USA
| | - Donald Heald
- Janssen Research & Development, LLC, Raritan, NJ, USA
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Abstract
INTRODUCTION Migraine is a very common medical disorder characterized by attacks of moderate-severe headache, nausea and disability. Topiramate is an effective, popular prophylactic migraine treatment, which is approved for use in adults and adolescents. Due to its multiple mechanisms of action, topiramate has multiple potential safety issues, including systemic and CNS adverse events, which may complicate therapy. AREAS COVERED This review evaluates common adverse events as seen in the pivotal trials of topiramate for migraine as well as those observed in postmarketing studies. These include weight loss, metabolic acidosis, renal calculi, acute angle closure glaucoma, visual distortions and cognitive slowing. Topiramate use during pregnancy is associated with an increased risk of cleft lip. This review highlights both common and unusual safety issues associated with topiramate use, including important drug interactions and a comparison with other migraine prophylactic agents. EXPERT OPINION Topiramate is highly effective in migraine prophylaxis but clinicians using the drug need to be aware of the potential for bothersome or serious adverse events. When treating with topiramate, use a slow titration to the goal dose of 100 mg or the lowest dose, which helps prevent migraine.
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Affiliation(s)
- Michael J Marmura
- Thomas Jefferson University, Jefferson Headache Center, Department of Neurology , 900 Walnut Street, Suite 200, PA 19107 , USA +1 215 955 2243 ; +1 215 955 2060 ;
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Gupta PP, Thacker AK, Haider J, Dhawan S, Pandey N, Pandey AK. Assessment of topiramate's efficacy and safety in epilepsy. J Neurosci Rural Pract 2014; 5:144-8. [PMID: 24966552 PMCID: PMC4064179 DOI: 10.4103/0976-3147.131657] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Objective: To study the significance of topiramate (TPM) addition on seizure control in treatment of epilepsy. Design: A prospective open label add-on trial of TPM addition in patients with epilepsy was done. The events of baseline phase of 12 weeks followed by titration and maintenance phases were recorded. Assessment of the number of seizure and emergent adverse effects was done by a monthly visit for each case. Main Outcome Measures: Reduction of more than 50% mean seizure frequency or response ratio of 0.33 was taken as the criteria for responders. Statistical Analysis: Normal Z-test for significance of differences between two proportions and Chi-square test for presence of association was applied and mean age, median duration, sex ratio, percentage prevalence were depicted. Results: Significant responses to TPM in both partial as well as generalized seizures were observed (Z = 6.66, P < 0.001 and Z = 4.185, P < 0.01). The effect was more pronounced in patients with partial seizures. However, the overall response was highly significant (Z = 7.839, P < 0.001). The best response was noted at the dose of 200–300 mg/day (Z = 6.708, P < 0.001). More than 35% cases of partial and generalized seizures reported more than 75% reduction levels. The drug was well tolerated in more than 65% cases for side effects on psychosis, giddiness, and anorexia. Mild side effects were seen only in about less than 35% cases. Conclusions: TPM was found as a significantly effective add-on anticonvulsant with some limitation or mild side effects.
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Affiliation(s)
- Prem P Gupta
- Department of Pharmacology, All India Institute of Medical Sciences, Patna, Bihar, India
| | - Anup Kumar Thacker
- Department of Neurology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Jamal Haider
- Department of Pharmacology, Baba Raghav Das Medical College, Uttar Pradesh, India
| | - Shilpi Dhawan
- Department of Pharmacology, Baba Raghav Das Medical College, Uttar Pradesh, India
| | - Neerjesh Pandey
- Department of Pharmacology, TMC, Teerthanker Mahaveer University, Moradabad, Uttar Pradesh, India
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Hedera P, Cibulčík F, Davis TL. Pharmacotherapy of essential tremor. J Cent Nerv Syst Dis 2013; 5:43-55. [PMID: 24385718 PMCID: PMC3873223 DOI: 10.4137/jcnsd.s6561] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 11/10/2013] [Accepted: 11/25/2013] [Indexed: 12/11/2022] Open
Abstract
Essential tremor (ET) is a common movement disorder but its pathogenesis remains poorly understood. This has limited the development of effective pharmacotherapy. The current therapeutic armamentaria for ET represent the product of careful clinical observation rather than targeted molecular modeling. Here we review their pharmacokinetics, metabolism, dosing, and adverse effect profiles and propose a treatment algorithm. We also discuss the concept of medically refractory tremor, as therapeutic trials should be limited unless invasive therapy is contraindicated or not desired by patients.
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Affiliation(s)
- Peter Hedera
- Department of Neurology, Vanderbilt University, Nashville, TN
| | - František Cibulčík
- Department of Neurology, Slovak Medical University and University Hospital Bratislava, Slovakia
| | - Thomas L Davis
- Department of Neurology, Vanderbilt University, Nashville, TN
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16
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Moore CF, Protzuk OA, Johnson BA, Lynch WJ. The efficacy of a low dose combination of topiramate and naltrexone on ethanol reinforcement and consumption in rat models. Pharmacol Biochem Behav 2013; 116:107-15. [PMID: 24252444 DOI: 10.1016/j.pbb.2013.11.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 11/07/2013] [Accepted: 11/08/2013] [Indexed: 10/26/2022]
Abstract
RATIONALE Combined medication approaches, by targeting multiple neurotransmitter systems involved in alcohol use disorders (AUDs), may be more efficacious than single-medication approaches. OBJECTIVES We examined, in animal models of consumption and reinforcement, the combined effects of naltrexone (an opioid antagonist) and topiramate (a GABA/glutamate modulator), two medications that have shown promise for treating AUDs, hypothesizing that their combination would be more efficacious than either alone. METHODS The effects of naltrexone and topiramate on ethanol consumption were examined in alcohol preferring (P) rats (N=10) and in rats from their background strain (Wistar, N=9) using conditions that induce high levels of consumption (24-h, 3-bottle, free-choice procedure). Low doses of each medication (1mg/kg, naltrexone; 10mg/kg, topiramate) were selected in an attempt to maximize their combined efficacy while minimizing potential side-effects. Their effects on ethanol reinforcement were assessed under a progressive-ratio schedule in additional groups of (N=22) P rats. A moderate dose of topiramate (20mg/kg) was also included to verify topiramate's efficacy on its own. RESULTS In P rats, but not in Wistar rats, the combination effectively and persistently reduced consumption; whereas, neither dose alone was effective. The combination and naltrexone alone were equally effective at reducing ethanol reinforcement; however, with the combination, but not naltrexone alone, this effect was selective for ethanol. All treatments produced a similar decrease in home-cage food consumption. The 20mg/kg dose of topiramate also effectively reduced ethanol consumption and reinforcement. CONCLUSIONS With greater efficacy and fewer side-effects, the combination shows promise as a treatment for AUDs.
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Affiliation(s)
- Catherine F Moore
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA, United States
| | - Omar A Protzuk
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA, United States
| | - Bankole A Johnson
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA, United States
| | - Wendy J Lynch
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA, United States.
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Clark AM, Kriel RL, Leppik IE, White JR, Henry TR, Brundage RC, Cloyd JC. Intravenous topiramate: Safety and pharmacokinetics following a single dose in patients with epilepsy or migraines taking oral topiramate. Epilepsia 2013; 54:1106-11. [DOI: 10.1111/epi.12165] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Anne M. Clark
- Upsher-Smith Laboratories; Minneapolis Minnesota U.S.A
| | - Robert L. Kriel
- Center for Orphan Drug Research; University of Minnesota; Minneapolis Minnesota U.S.A
- Department of Experimental and Clinical Pharmacology; College of Pharmacy; University of Minnesota; Minneapolis Minnesota U.S.A
| | - Ilo E. Leppik
- Department of Experimental and Clinical Pharmacology; College of Pharmacy; University of Minnesota; Minneapolis Minnesota U.S.A
- MINCEP Epilepsy Care; Minneapolis Minnesota U.S.A
- Department of Neurology; University of Minnesota; Minneapolis Minnesota U.S.A
| | | | - Thomas R. Henry
- Department of Neurology; University of Minnesota; Minneapolis Minnesota U.S.A
| | - Richard C. Brundage
- Department of Experimental and Clinical Pharmacology; College of Pharmacy; University of Minnesota; Minneapolis Minnesota U.S.A
| | - James C. Cloyd
- Center for Orphan Drug Research; University of Minnesota; Minneapolis Minnesota U.S.A
- Department of Experimental and Clinical Pharmacology; College of Pharmacy; University of Minnesota; Minneapolis Minnesota U.S.A
- Department of Neurology; University of Minnesota; Minneapolis Minnesota U.S.A
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18
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Factors Influencing Serum Topiramate Concentrations in Routine Therapeutic Drug Monitoring in Korean Adult Patients With Epilepsy. Ther Drug Monit 2013; 35:177-82. [DOI: 10.1097/ftd.0b013e31827efe1d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Pharmacokinetic variability of four newer antiepileptic drugs, lamotrigine, levetiracetam, oxcarbazepine, and topiramate: a comparison of the impact of age and comedication. Ther Drug Monit 2013; 34:440-5. [PMID: 22777154 DOI: 10.1097/ftd.0b013e31825ee389] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Newer antiepileptic drugs (AEDs) are widely used in patients with epilepsy. There is still insufficient documentation regarding pharmacokinetic variability of these AEDs in different patient groups. PURPOSE The purpose of this study was to compare age and comedication as factors contributing to pharmacokinetic variability between 4 newer AEDs (lamotrigine, levetiracetam, oxcarbazepine, and topiramate) among patients with refractory epilepsy. METHODS Data regarding age, gender, use of AEDs, daily doses, and serum concentration measurements were retrieved from a therapeutic drug monitoring database, from patients admitted to the National Center for Epilepsy, Norway, 2007-2008. RESULTS In total, 1050 patients were included, 111 younger children (2-9 years), 137 older children (10-17 years), 720 adults (18-64 years), 82 elderly (65-93 years). Fifty percent of the patients were prescribed polytherapy, in 88 different combinations. The interindividual pharmacokinetic variability was extensive, as illustrated by a 10-fold variability in serum concentration compared with dose. Age affected the apparent clearance of levetiracetam to the largest extent, as shown by a 60% increase in younger children and a 40% reduction in the elderly, respectively, compared with adults. Comedication altered the clearance of lamotrigine to the greatest extent ±70% because it is affected by both enzyme inducers and inhibitors. Hepatic enzyme inducers increased the clearance of levetiracetam and topiramate by 25% and oxcarbazepine by 75%. Valproic acid reduced the clearance of topiramate by 25%. CONCLUSION Age and comedication are important contributors to pharmacokinetic variability. Age had the greatest impact on levetiracetam, and comedication affected the clearance of each of the 4 AEDs investigated in this study. Pharmacokinetic drug interactions must be carefully considered when multidrug therapies are prescribed. Therapeutic drug monitoring is a valuable tool for individualizing AED therapy.
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Ferrari A, Tiraferri I, Neri L, Sternieri E. Clinical pharmacology of topiramate in migraine prevention. Expert Opin Drug Metab Toxicol 2011; 7:1169-81. [PMID: 21756204 DOI: 10.1517/17425255.2011.602067] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
INTRODUCTION Migraine is a widespread disorder. Migraine patients experience worse health-related quality of life than the general population. The availability of effective and tolerable treatments for this disorder is an important medical need. This narrative review focuses on the clinical pharmacology of topiramate, an antiepileptic drug that was approved for the prophylaxis of migraine where it should act as a neuromodulator. AREAS COVERED A PubMed database search (from 2000 to 24 January 2011) and a review of the human studies published on topiramate and migraine was conducted. EXPERT OPINION Topiramate is an important option for the prophylaxis of migraine and is of proven efficacy and tolerability. It has also been studied in chronic migraine with encouraging results, even in patients with medication overuse. However, in migraine prevention its efficacy is comparable to the other first-line drugs and there are no published trials with a superiority design which can establish topiramate's role in the available therapeutic armamentarium.
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Affiliation(s)
- Anna Ferrari
- University of Modena and Reggio Emilia, Headache and Drug Abuse Inter-Dep. Research Centre, Division of Toxicology and Clinical Pharmacology, Modena, Italy.
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Kerr MP, Merrick J. A review of the use of Topiramate in people with intellectual disability. Int J Adolesc Med Health 2011; 12:87-102. [PMID: 22912311 DOI: 10.1515/ijamh.2000.12.s1.87] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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22
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Matar KM. Therapeutic drug monitoring of topiramate by liquid chromatography-tandem mass spectrometry. Clin Chim Acta 2010; 411:729-34. [DOI: 10.1016/j.cca.2010.02.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2010] [Revised: 02/01/2010] [Accepted: 02/02/2010] [Indexed: 11/17/2022]
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Filippi L, la Marca G, Fiorini P, Poggi C, Cavallaro G, Malvagia S, Pellegrini-Giampietro DE, Guerrini R. Topiramate concentrations in neonates treated with prolonged whole body hypothermia for hypoxic ischemic encephalopathy. Epilepsia 2009; 50:2355-61. [PMID: 19744111 DOI: 10.1111/j.1528-1167.2009.02302.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
PURPOSE Therapeutic hypothermia reduces mortality and neurologic impairment in neonates with hypoxic-ischemic encephalopathy. Topiramate exerts a neuroprotective effect in asphyxiated neonatal animal models. However, no studies have investigated the association of hypothermia and topiramate, because topiramate pharmacokinetics during hypothermia and the optimal administration schedule are unknown. The influence of hypothermia on topiramate pharmacokinetics was evaluated in asphyxiated neonates treated with prolonged whole-body hypothermia and topiramate. METHODS Thirteen term newborns were treated with mild or deep whole body hypothermia for 72 h; all received oral topiramate, 5 mg/kg once a day for the first 3 days of life, and seven had concomitant phenobarbital treatment. Topiramate concentrations were measured on serial dried blood spots. RESULTS Topiramate concentrations were within the reference range in 11 of 13 newborns, whereas concentrations exceeded the upper limit in 2 of 13, both newborns on deep hypothermia. Topiramate concentrations reached a virtual steady state in nine newborns, for whom pharmacokinetic parameters were calculated. Values of topiramate maximal and minimal concentration, half-life, average concentration, and area under the time-concentration curve resulted in considerably higher values than those reported in normothermic infants. With respect to normothermic infants, time of maximal concentration was mildly delayed and apparent total body clearance was lower, suggesting slower absorption and elimination. Pharmacokinetic parameters did not differ significantly between infants on deep versus mild hypothermia and in those on topiramate monotherapy versus add-on phenobarbital. CONCLUSION Most neonates on prolonged hypothermia treated with topiramate 5 mg/kg once a day exhibited drug concentrations within the reference range for the entire treatment duration.
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Affiliation(s)
- Luca Filippi
- Neonatal Intensive Care Unit, Department of Critical Care Medicine, A. Meyer University Children's Hospital, Florence, Italy.
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Morota S, Månsson R, Hansson MJ, Kasuya K, Shimazu M, Hasegawa E, Yanagi S, Omi A, Uchino H, Elmér E. Evaluation of putative inhibitors of mitochondrial permeability transition for brain disorders--specificity vs. toxicity. Exp Neurol 2009; 218:353-62. [PMID: 19348797 DOI: 10.1016/j.expneurol.2009.03.036] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Revised: 03/23/2009] [Accepted: 03/26/2009] [Indexed: 12/16/2022]
Abstract
Inhibition of mitochondrial permeability transition (mPT) has emerged as a promising approach for neuroprotection and development of well-tolerated mPT inhibitors with favorable blood-brain barrier penetration is highly warranted. In a recent study, 28 clinically available drugs with a common heterocyclic structure were identified as mPT inhibitors e.g. trifluoperazine, promethazine and nortriptyline. In addition, neuroprotection by structurally unrelated drugs e.g. neurosteroids, 4-hydroxy-tamoxifen and trimetazidine has been attributed to direct inhibition of mPT. The regulation of mPT is complex and highly dependent on the prevailing experimental conditions. Several features of mPT, such as swelling, depolarization or NADH oxidation, can also occur independently of the mPT phenomenon. Here, in isolated rodent brain-derived and human liver mitochondria, we re-evaluate drugs promoted as potent mPT inhibitors. We address the definition of an mPT inhibitor and present strategies to reliably detect mPT inhibition in vitro. Surprisingly, none of the 12 compounds tested displayed convincing mPT inhibition or effects comparable to cyclophilin D inhibition by the non-immunosuppressive cyclophilin inhibitor D-MeAla(3)-EtVal(4)-Cyclosporin (Debio 025). Propofol and 2-aminoethoxydiphenyl borate (2-APB) inhibited swelling in de-energized mitochondria but did not increase calcium retention capacity (CRC). Progesterone, trifluoperazine, allopregnanolone and 4-hydroxy-tamoxifen dose-dependently reduced CRC and respiratory control and were thus toxic rather than beneficial to mitochondrial function. Interestingly, topiramate increased CRC at high concentrations likely by a mechanism separate from direct mPT inhibition. We conclude that a clinically relevant mPT inhibitor should have a mitochondrial target and increase mitochondrial calcium retention at concentrations which can be translated to human use.
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Affiliation(s)
- Saori Morota
- Department of Clinical Sciences, Lund University, Sweden
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Hovinga CA, Pennell PB. Antiepileptic drug therapy in pregnancy II: fetal and neonatal exposure. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2009; 83:241-58. [PMID: 18929086 DOI: 10.1016/s0074-7742(08)00014-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The issue of how much an antiepileptic drug (AED) crosses the placenta and relative safety of lactation in mothers receiving AEDs are common clinical questions. Educating potential mothers with epilepsy regarding available information is warranted so that informed decisions and any needed neonatal monitoring is performed. Unfortunately, there is still limited data regarding the degree in which anticonvulsants cross the placenta and penetrate into breast milk. There is a greater appreciation of the factors that influence AED passive transfer across the placenta and into breast milk, as well as factors that ultimately influence neonatal AED distribution. In general, women with epilepsy can have healthy babies even with significant placental exposure and can breast-feed their babies safely with some cautions. Phenobarbital and primidone should be avoided in parents wishing to breast-feed. For the AEDs ethosuximide, levetiracetam, lamotrigine, topiramate, and zonisamide, there is a potential for significant breast milk concentrations; however, there are no firm guidelines on whether lactation is safe. In all cases, parents should be counseled to monitor their child for side effects and the need for routine monitoring.
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Affiliation(s)
- Collin A Hovinga
- Departments of Clinical Pharmacy and Pediatrics, University of Tennessee Health Science Center, LeBonheur Children's Medical Center, Memphis, Tennessee 38105, USA
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Ben-Menachem E, Sander JW, Stefan H, Schwalen S, Schäuble B. Topiramate monotherapy in the treatment of newly or recently diagnosed epilepsy. Clin Ther 2008; 30:1180-95. [PMID: 18691980 DOI: 10.1016/s0149-2918(08)80045-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The efficacy of topiramate (TPM) as an adjunctive treatment for epilepsy has been established in placebo-controlled clinical trials. Clinical trials of antiepileptic monotherapy usually evaluate low and high doses of study drug or compare study drug with another active agent. OBJECTIVE This article reviews available evidence for the use of TPM as monotherapy in patients with newly or recently diagnosed epilepsy. METHODS A search of MEDLINE, EMBASE, BIOSIS, SCISEARCH, and the Cochrane Database of Systematic Reviews (all years) for reports of controlled trials of TPM monotherapy in patients with recently diagnosed (within the previous 3 years) epilepsy was conducted in January 2008 using the terms topiramate, epilepsy, newly diagnosed, recently diagnosed, and monotherapy. Identified trials were included in the review if they were published in peer-reviewed journals and enrolled > or = 20 patients. RESULTS Three randomized, double-blind, controlled trials met the criteria for inclusion in the review. In a comparison of TPM 50 and 500 mg/d, the higher dose was associated with significantly greater freedom from seizures at 6 months compared with the lower dose (54% vs 39%, respectively; P = 0.02). The time to first seizure was significantly associated with mean plasma TPM concentrations (P = 0.015). In a comparison of TPM 50 and 400 mg/d, the time to first seizure was significantly longer with the higher dose compared with the lower dose (P<0.001, Kaplan-Meier analysis), and the probability of 12-month seizure freedom was significantly higher (76% vs 59%, respectively; P = 0.001). Again, the time to first seizure was significantly associated with mean plasma TPM concentrations (P = 0.029). In a comparative study of TPM 100 and 200 mg/d, carbamazepine 600 mg/d, and valproate 1250 mg/d, there was no significant difference in rates of 6-month seizure freedom with TPM 100 and 200 mg/d (49% and 44%, respectively), carbamazepine (44%), and valproate (44%). Adverse events in the 3 studies were similar between TPM dose groups, although the incidence generally increased with increasing doses, occurred early in treatment, and decreased with prolonged therapy. In a pooled analysis of the 3 trials, the most commonly occurring adverse events during dose titration were paresthesia (25%), fatigue (16%), dizziness (13%), somnolence (13%), and nausea (10%); the most frequent adverse events during maintenance therapy were headache (20%), decreased appetite (11%), and weight loss (11%). CONCLUSION In the 3 studies reviewed, TPM monotherapy was effective and generally well tolerated in patients with newly diagnosed epilepsy.
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Affiliation(s)
- Elinor Ben-Menachem
- Department of Clinical Neuroscience, Section of Neurology, Sahlgren University Hospital, Göteborg, Sweden.
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Ramsay RE, Uthman B, Pryor FM, Rowan AJ, Bainbridge J, Spitz M, Sirven JI, Frederick TE. Topiramate in older patients with partial-onset seizures: a pilot double-blind, dose-comparison study. Epilepsia 2008; 49:1180-5. [PMID: 18494791 DOI: 10.1111/j.1528-1167.2008.01584.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE Pharmacokinetics of antiepileptic drugs (AEDs) can be altered by age-related changes in physiology, thereby altering clinical effects, especially tolerability, in older adults. We compared two dosages of topiramate (TPM) in a pilot study of patients >or=60 years of age with partial-onset seizures. METHODS In this 24-week, double-blind, randomized, parallel-group study, patients with one or more seizures in previous 6 months were randomized to treatment with 50 or 200 mg/day TPM. TPM was initiated as monotherapy or added to one AED and titrated by 25 mg/day per week to target or maximum tolerated dose as the concomitant AED, if any, was withdrawn. RESULTS Thirty-eight patients were randomized to the 50 mg/day TPM (mean age, 68 years) and 39-200 mg/day TPM (69 years). Seizure control was similar with the two dosages when TPM could be used as monotherapy, whereas 200 mg TPM was more effective than 50 mg in patients requiring adjunctive therapy. The overall incidence of adverse events was similar for the two dosages--66% with 50 mg and 62% with 200 mg TPM. Most common adverse events were somnolence (TPM 50, 13%; TPM 200, 8%), dizziness (13% vs. 8%), and headache (13% vs. 5%). Of 10 (13%) patients reporting a cognitive-related adverse event, six patients were assigned to the 50-mg group. A total of 14 patients (18%; seven in each group) discontinued TPM due to adverse events. CONCLUSIONS This pilot study supports the practice of using low-to-moderate dosages of AEDs in older adults.
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Abstract
Topiramate (Topamax) is a structurally novel broad-spectrum antiepileptic drug (AED) with established efficacy as monotherapy or adjunctive therapy in the treatment of adult and paediatric patients with generalised tonic-clonic seizures, partial seizures with or without generalised seizures, and seizures associated with Lennox-Gastaut syndrome. The incidence and severity of many adverse events, including CNS-related events, may be reduced through the use of slow titration to effective and well tolerated dosages. It is associated with few clinically significant interactions with other drugs, is effective when used with other AEDs, is not associated with drug-induced weight gain and, at lower dosages, does not interfere with the effectiveness of oral contraceptives. Therefore, topiramate is a valuable option as monotherapy or adjunctive therapy in the treatment of epilepsy in adult and paediatric patients.
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Topiramate reduces non-convulsive seizures after focal brain ischemia in the rat. Neurosci Lett 2008; 430:7-12. [DOI: 10.1016/j.neulet.2007.09.052] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2007] [Revised: 08/08/2007] [Accepted: 09/26/2007] [Indexed: 11/18/2022]
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Abstract
Topiramate (TPM) is a widely-used drug for the treatment of epilepsy. It is useful for several types of partial-onset and generalized-onset seizures, and is therefore considered a broad-spectrum agent. It is also effective as a prophylactic against migraine headaches. TPM was first approved for prescription use in 1996. In various countries it is now approved for adjunctive and monotherapy of partial-onset seizures and for therapy of generalized tonic-clonic seizures of nonfocal origin, for children and adults. For initial monotherapy of new-onset seizures, a target dose of 100 mg/day for adults is recommended. Adjunctive use with enzyme-inducing drugs and use for refractory seizures requires higher dosages, though the optimum dose for most patients does not exceed 400 mg/day. Excretion is primarily renal and TPM is not a significant hepatic enzyme inducer. Although it is usually safe and well-tolerated, adverse effects limit use in about 25% of patients. The most salient of these is cognitive dysfunction, especially problems with expressive speech and verbal memory. Weight loss, renal stones, paresthesias and other central nervous system side effects may occur. Tolerability is improved by low initial doses and slow titration to effect.
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Affiliation(s)
- Edward Faught
- Department of Neurology, University of Alabama School of Medicine, Birmingham, Alabama, USA.
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Abstract
Many new antiepileptic drugs (AEDs) have become available over the past 15 years. At the same time, the emphasis on treating patients with epilepsy has grown from stopping seizures to avoiding side effects and maximizing quality of life. This review summarizes currently available AEDs, and presents general treatment principles and guidelines for AED selection. Unfortunately, despite the increased treatment options of today, seizure freedom without side effects remains unattainable for too many patients with epilepsy. Consequently, there remains a significant need for further development of new therapies.
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32
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Láinez MJA. Topiramate in migraine prophylaxis. FUTURE NEUROLOGY 2006. [DOI: 10.2217/14796708.1.4.357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Many of the drugs available for the prophylaxis of migraine never underwent rigorous placebo-controlled trials, and the effective drugs have side effects that are problematic in daily practice. Three double-blind studies involving more than 1500 patients (the largest clinical development program ever undertaken for migraine prophylaxis) consistently found topiramate, at doses of 100 and 200 mg/day, to be superior to placebo in migraine prophylaxis. Topiramate has demonstrated efficacy in reducing the frequency of migraines, producing a statistically significant effect at 1 month and maintaining effectiveness over more than 6 months. It is not associated with the side effects that may cause patients to stop taking other prophylactic medications.
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Affiliation(s)
- Miguel JA Láinez
- University of Valencia, Department of Neurology, Hospital Clinic University, Avda Blasco Ibáñez 17, 46010 Valencia, Spain
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Michelucci R, Passarelli D, Riguzzi P, Volpi L, Tassinari CA. The Preclinical and Therapeutic Activity of the Novel Anticonvulsant Topiramate. CNS DRUG REVIEWS 2006. [DOI: 10.1111/j.1527-3458.1998.tb00062.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Zanotta N, Raggi ME, Radice L, Degrate A, Bresolin N, Zucca C. Clinical experience with topiramate dosing and serum levels in patients with epilepsy. Seizure 2006; 15:86-92. [PMID: 16406695 DOI: 10.1016/j.seizure.2005.11.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2004] [Revised: 09/26/2005] [Accepted: 11/23/2005] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE To investigate the relevance of serum topiramate (TPM) levels (SL) monitoring in the clinical management of epileptic patients. METHODS Twenty-seven patients with different epileptic syndromes on TPM therapy were studied. TPM was used as add-on in 26 patients, only in one as monotherapy de novo; one case changed from TPM as add-on to TPM monotherapy. The mean follow-up time was 11 months. TPM SL were measured by fluorescence polarization immunoassay. RESULTS We analyzed the TPM SL in 43 samples from 27 patients. Mean TPM dose was 3.9mg/kg, mean TPM SL 13.43mumol/l. The mean level to dose ratio (LDR) was 3.63mumol/l/mg/kg. Four patients became seizure-free, all with TPM dosages lower than the mean. Eleven patients had at least 50% seizure reduction. The comedication with enzyme-inducing AED significantly reduced TPM SL and LDR. On the other hand, the influence of valproic acid (VPA) on TPM LDR was not univocal. Indeed, patients younger than 15 years showed SL values lower than the adults did, although not significant. CONCLUSION We could not detect a direct relationship between high TPM SL and efficacy neither between high TPM SL and tolerability. However, the data we collected seem to favour the hypothesis that high TPM dosage and SL might be associated to a greater probability to reduce seizure severity.
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Affiliation(s)
- Nicoletta Zanotta
- Clinical Neurophysiology Unit, IRCCS E. Medea, Via Don L. Monza 20, 23842 Bosisio Parini (Lc), Italy.
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Aykutlu E, Baykan B, Gürses C, Bebek N, Büyükbabani N, Gökyigit A. Add-on therapy with topiramate in progressive myoclonic epilepsy. Epilepsy Behav 2005; 6:260-3. [PMID: 15710314 DOI: 10.1016/j.yebeh.2004.11.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2004] [Revised: 11/23/2004] [Accepted: 11/23/2004] [Indexed: 11/20/2022]
Abstract
We evaluated the clinical responses to add-on therapy with topiramate in eight patients with progressive myoclonic epilepsy (PME). Severe myoclonic seizures disturbing daily activities were persistent despite adequate trials of various combinations of antiepileptic drugs in all patients. After the initiation of topiramate therapy, five patients had a marked decrease in myoclonic seizure frequency, prominent improvement of daily functioning, and recovery from previous drug-related side effects such as weight gain and irregularities of menstruation due to polycystic ovary syndrome. However, we had to discontinue topiramate in three patients because of side effects. Topiramate seems to be a useful alternative agent in the treatment of PME. The antimyoclonic effect provides some independence in daily activities and decreases the side effects related to other antiepileptic drugs, which are clear benefits for this grave disease, although having a short-term effect in some patients.
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Affiliation(s)
- Ebru Aykutlu
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
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Silberstein SD, Ben-Menachem E, Shank RP, Wiegand F. Topiramate monotherapy in epilepsy and migraineprevention. Clin Ther 2005; 27:154-65. [PMID: 15811478 DOI: 10.1016/j.clinthera.2005.02.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/17/2004] [Indexed: 12/01/2022]
Abstract
OBJECTIVES The purposes of this review were to assess the efficacy of topiramate as monotherapy for epilepsy and migraine prevention, describe how it should be used, and give clinical advice on how to manage the practical aspects of dosing, titration, and possible adverse events in these 2 indications. METHODS We searched the PubMed and BIOSIS databases using the key words topiramate, epilepsy, and migraine from the year 1987 onward, and subsequently focused the search on larger controlled trial studies of topiramate as monotherapy. RESULTS Studies have evaluated the use of topiramate as monotherapy in the treatment of partial-onset and generalized seizures and in the prevention of migraine. In a randomized study, 75% of epilepsy patients treated with 400 mg/d topiramate remained seizure free at 1 year. Patients in the same study treated with a lower dose of topiramate (50 mg/d) also experienced notable seizure reductions, with 59% of patients free of seizures at 1 year. A comparison trial of topiramate (100 or 200 mg/d), valproate, and carbamazepine found that topiramate was associated with a similar time to first posttreatment seizure as the other 2 agents (P = NS). Trials of topiramate monotherapy in migraine prevention found that 100 mg/d was associated with a > or =50% reduction in monthly migraine frequency in 49% to 54% of patients. The migraine prevention trials typically used a starting dose of 25 mg/d, with weekly increases of 25 mg and an initial monotherapy target dose of 100 mg/d. The most common adverse events associated with topiramate are paresthesia, weight loss, and other centrally mediated symptoms, many of which may be ameliorated by proper titration and dosing and by good communication between physician and patient. CONCLUSIONS Data from controlled trials suggest that 100 mg/d topiramate as monotherapy is effective in the treatment of partial-onset and generalized seizures and in the prevention of migraine.
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Affiliation(s)
- Stephen D Silberstein
- Thomas Jefferson University, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania 19107, USA.
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Abstract
OBJECTIVE The goal of this study was to report the effectiveness of topiramate in treating status epilepticus. METHODS Three patients with status epilepticus were treated with topiramate 500 mg twice daily for 2-5 days, with the dose gradually tapered thereafter to 200 mg twice daily. The patients' clinical status and EEG recordings were followed. RESULTS Patient 1 was admitted for subacute encephalopathy that was complicated by secondarily generalized status epilepticus resistant to lorazepam, fosphenytoin, and pentobarbital coma. Topiramate was added and, 2 days later, pentobarbital was tapered with no recurrence of ictal discharges as the patient improved clinically. Patient 2 had end-stage liver disease and was hospitalized for peritonitis, and his course was complicated by partial status epilepticus. Topiramate was started and, 2 days later, his mental status improved as repeat EEG showed no further ictal discharges although periodic epileptiform discharges were seen in the left centroparietal area. The patient later died from complications of variceal bleeding. Patient 3 suffered cardiopulmonary arrest, and developed postanoxic seizures, which did not respond to lorazepam, fosphenytoin, valproate, and propofol coma as continuous EEG recordings showed recurrent generalized ictal discharges. Two days after topiramate was started, propofol was tapered and discontinued and EEG showed generalized slow wave activity and no ictal discharges. The patient was discharged to another facility 12 days later. CONCLUSIONS Topiramate was effective in treating two patients with refractory generalized status epilepticus and one with complex partial status epilepticus. It should therefore be considered as an option in these situations, especially when other medications cannot be used.
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Affiliation(s)
- Meriem K Bensalem
- Department of Neurology, University of Kentucky Medical Center, L-445 Kentucky clinic, 740 South Limestone, 40536-0284, Lexington, KY, USA
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Ohman I, Vitols S, Luef G, Söderfeldt B, Tomson T. Topiramate kinetics during delivery, lactation, and in the neonate: preliminary observations. Epilepsia 2002; 43:1157-60. [PMID: 12366729 DOI: 10.1046/j.1528-1157.2002.12502.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To study the pharmacokinetics of topiramate (TPM) during delivery, lactation, and in the neonate. METHODS TPM concentrations in plasma and breast milk were measured with fluorescence polarization immunoassay (FPIA) in five women with epilepsy treated with TPM during pregnancy and lactation. Blood samples were obtained at delivery from mothers, from the umbilical cord, and from the newborns on three occasions (24, 48, and 72 h) after delivery. Blood and breast milk also were collected from mothers 2 weeks, and 1 and 3 months postpartum. Blood samples also were drawn from the infants during breast-feeding. Three of the mother-infant pairs were studied both at delivery and during lactation; two contributed with data from delivery only. RESULTS The umbilical cord plasma/maternal plasma ratios were close to unity, suggesting extensive transplacental transfer of TPM. The mean milk/maternal plasma concentration ratio was 0.86 (range, 0.67-1.1) at 2-3 weeks after delivery. The milk/maternal plasma concentration ratios at sampling 1 and 3 months after delivery were similar (0.86 and 0.69, respectively). Two to 3 weeks after delivery, two of the breast-fed infants had detectable (>0.9 microM) concentrations of TPM, although below the limit of quantification (2.8 microM), and one had an undetectable concentration. CONCLUSIONS Our limited data suggest free passage of TPM over the placenta and an extensive transfer into breast milk. Breast-fed infants had very low TPM concentrations, and no adverse effects were observed in the infants.
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Affiliation(s)
- Inger Ohman
- Departments of Internal Medicine, Division of Clinical Pharmacology and Clinical Neuroscience, Karolinska Hospital, and Department of Neuroscience and Locomotion, Linköping University, Stockholm and Linköping, Sweden.
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May TW, Rambeck B, Jürgens U. Serum concentrations of topiramate in patients with epilepsy: influence of dose, age, and comedication. Ther Drug Monit 2002; 24:366-74. [PMID: 12021627 DOI: 10.1097/00007691-200206000-00007] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Topiramate is a new antiepileptic drug (AED) approved as add-on therapy. Previous studies have shown that topiramate has only a limited effect on other AEDs, but its own metabolism can be induced by enzyme-inducing drugs. The aim of this study was to investigate the influence of topiramate dose, age, and comedication, especially of carbamazepine, phenytoin, phenobarbital, oxcarbazepine, lamotrigine, and valproic acid (VPA) on topiramate serum concentrations in patients with epilepsy. In total, 480 samples of 344 inpatients who fulfilled the inclusion criteria (e.g., trough concentration, body weight available) were investigated. The topiramate serum concentration in relation to topiramate dose per body weight (level-to-dose ratio) was calculated and compared for patients receiving topiramate monotherapy and for patients receiving topiramate plus one other AED. Analysis of covariance (using age as covariate) showed that comedication had a highly significant influence on the topiramate serum concentrations. Regression analysis including all 480 samples confirmed that in combinations with phenytoin, carbamazepine, phenobarbital, and oxcarbazepine, the topiramate concentrations were significantly lower compared with topiramate monotherapy, whereas VPA and lamotrigine had no significant influence. Moreover, regression analysis indicated that primidone and methsuximide lowered topiramate concentrations, whereas gabapentin, bromide, and sulthiame did not. In addition to comedication, the patient's age was significantly correlated with topiramate clearance. In accordance with the results of previous studies, these results indicated that infants and children had lower topiramate concentrations than adults receiving the same topiramate dose per body weight. Comedication and age should be considered in adjusting topiramate dosage. Determination of topiramate serum concentrations may be useful, especially when enzyme-inducing drugs are withdrawn or added.
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Affiliation(s)
- Theodor W May
- Department of Biochemistry, Gesellschaft für Epilepsieforschung, Maraweg 13, D-33546 Bielefeld, Germany.
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Chollet DF. Determination of antiepileptic drugs in biological material. J Chromatogr B Analyt Technol Biomed Life Sci 2002; 767:191-233. [PMID: 11885851 DOI: 10.1016/s0378-4347(01)00502-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Current analytical methodologies applied to the determination of antiepileptic drugs in biological material are reviewed. The role of chromatographic techniques is emphasized. Special attention is focused on new chemical entities as well as current trends such as high-speed liquid chromatographic techniques, hyphenated techniques and electrochromatography techniques. A review with 542 references.
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Affiliation(s)
- Daniel F Chollet
- Covance Central Laboratory Services SA, Drug Monitoring Department, Meyrin/Geneva, Switzerland.
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Abstract
Oxcarbazepine is a new antiepileptic drug (AED) that has been registered in more than 50 countries worldwide since 1990 and recently received approval in the United States and the European Union. Oxcarbazepine is a keto analog of carbamazepine and has a more favorable pharmacokinetic profile. It is rapidly absorbed after oral administration and undergoes rapid and almost complete reductive metabolism to form the pharmacologically active 10-monohydroxy derivative. Oxcarbazepine exhibits linear pharmacokinetics, no autoinduction, and minimal interaction with other AEDs. Ten controlled trials demonstrated that oxcarbazepine is safe and efficacious in the treatment of partial seizures across a wide range of ages (children to adults), situations (recent onset to treatment-resistant epilepsy), and uses (monotherapy and adjunctive therapy). The most common treatment-emergent adverse events are related to the central nervous system. Treatment-emergent hyponatremia (defined as serum sodium level < 125 mEq/L) occurred in 3% of patients treated with oxcarbazepine in clinical trials. According to the efficacy and safety profile established in the controlled trials, oxcarbazepine represents an important new treatment option indicated for monotherapy and adjunctive therapy in adults with partial seizures and as adjunctive therapy in children aged 4 years or older with partial seizures. Although structurally similar to carbamazepine, significant differences exist in the pharmacokinetics, drug interaction potential, adverse-effect profile, and dosage and titration between these two agents, and they should be considered distinct therapeutic agents.
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Affiliation(s)
- T A Glauser
- Department of Neurology, Children's Comprehensive Epilepsy Program, Children's Hospital Medical Center, Cincinnati, Ohio 45229-3039, USA.
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Abstract
PURPOSE The short- and long-term pharmacodynamic effects of topiramate (TPM) on brain gammay-aminobutyric acid (GABA) metabolism were studied in patients with complex partial seizures. METHODS In vivo measurements of GABA, homocarnosine, and pyrrolidinone were made of a 14-cc volume in the occipital cortex using 1H spectroscopy with a 2.1-Tesla magnetic resonance spectrometer and an 8-cm surface coil. Fifteen patients (four men) were studied serially after the first, oral dose (100 mg) of TPM. RESULTS The first dose of TPM increased brain GABA within 1 h. Within 4 h, GABA was increased by 0.9 mM (95% CI, 0.7-1.1). Brain GABA remained elevated for > or =24 h. Pyrrolidinone and homocarnosine increased slowly during the first day. Daily TPM therapy (median, 300 mg; range, 200-500) increased GABA (0.3 mM; 95% CI, 0.1-0.5), homocarnosine (0.4 mM; 95% CI, 0.3-0.5), and pyrrolidinone (0.15 mM; 95% CI, 0.10-0.19), compared with levels before TPM. There was no dose response evident with daily TPM doses of 200-500 mg. CONCLUSIONS TPM promptly elevates brain GABA and presumably offers partial protection against further seizures within hours of the first oral dose. Patients may expect to experience the effects of increased homocarnosine and pyrrolidinone within 24 h.
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Affiliation(s)
- O A Petroff
- Department of Neurology, Yale University, New Haven, Connecticut 06520-8018, USA
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Takeoka M, Holmes GL, Thiele E, Bourgeois BF, Helmers SL, Duffy FH, Riviello JJ. Topiramate and metabolic acidosis in pediatric epilepsy. Epilepsia 2001; 42:387-92. [PMID: 11442157 DOI: 10.1046/j.1528-1157.2001.04500.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE Topiramate (TPM) has been widely used as an adjunctive therapy for treating epilepsy. TPM is reported to have multiple mechanisms of action, including inhibition of carbonic anhydrase, which may result in metabolic acidosis from decreased serum bicarbonate (HCO3-). METHODS Clinical data from 30 children who received TPM as adjunctive therapy for medically refractory epilepsy were reviewed at Children's Hospital, Boston. Serum HCO3- levels were assessed before, during, and after discontinuing TPM (n = 9). When multiple data were available, mean values were used for analysis. RESULTS Of the 30 patients, 21 had a >10% decrease in HCO3- levels. The mean decrease in HCO3- among the 21 patients was 4.7 mEq/L, and maximum was 10 mEq/L. No clinical symptoms occurred, and HCO3- supplement was not needed, except for one patient who developed tachypnea from worsened acidosis after prolonged status epilepticus during a suspected viral illness. Among the 21 patients, TPM was discontinued in seven children because of a lack of efficacy, and in two because of anorexia. After discontinuing TPM, the serum HCO3- returned to the previous level before starting TPM in all nine. CONCLUSIONS Decreased HCO3- levels occurred in the majority of patients reviewed, usually only to a small to moderate extent, but by 8 and 10 mEq/L in two cases. In patients at risk for acidosis, the decrease in HCO3- may cause significant consequences, such as severe acidosis or renal calculi. Monitoring HCO3- levels before and during TPM therapy may be indicated, especially with conditions that predispose to acidosis.
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Affiliation(s)
- M Takeoka
- Department of Neurology, Children's Hospital, and Harvard Medical School, Boston, Massachusetts, USA.
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Glauser TA, Pippenger CE. Controversies in blood-level monitoring: reexamining its role in the treatment of epilepsy. Epilepsia 2001; 41 Suppl 8:S6-15. [PMID: 11092608 DOI: 10.1111/j.1528-1157.2000.tb02950.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This article reexamines the role of blood-level monitoring (therapeutic drug monitoring, TDM) of antiepileptic drugs (AEDs) in the current treatment of epilepsy and identifies situations in which TDM can be useful. Basic pharmacokinetic and pharmacodynamic principles are reviewed, with specific emphasis on kinetics of absorption/distribution/metabolism, elimination half-life, time to steady state, and plasma drug concentrations. The relationship between AED intensity of effect (pharmacodynamics) and plasma concentration (pharmacokinetics) is expressed mathematically, examined in the context of the major old and new AEDs, and integrated with a historical look at the role of TDM. Situations in which TDM can be useful in the modern treatment of epilepsy are presented and discussed. For both older and newer AEDs, TDM is useful in six clinical situations: establishing "baseline" effective concentrations, evaluating potential causes for lack of efficacy, evaluating potential causes for toxicity, evaluating potential causes for loss of efficacy, judging "room to move" or when to change AEDs, and minimizing predictable problems. TDM remains a valuable tool in the modern treatment of epilepsy. It can be selectively and appropriately utilized to help maximize seizure control and minimize side effects if levels are obtained in response to a patient-specific pharmacokinetic or pharmacodynamic issue or problem.
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Affiliation(s)
- T A Glauser
- Department of Neurology, Children's Hospital Medical Center, Cincinnati, Ohio 45229-3039, USA
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Abstract
The successful management of epilepsy requires a thorough and individualized approach that accurately establishes the patient's seizure type(s) and, when appropriate, epilepsy syndrome. Selection of pharmacologic and nonpharmacologic therapy should be rational and tailored to each patient. In this manner, clinicians are able to take advantage of new treatments to minimize the impact of seizures, treatment side effects, and epilepsy-related psychosocial difficulties on their patients, thereby enabling them to function in society at the highest possible level.
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Affiliation(s)
- S C Schachater
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
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Abstract
Epilepsy affects 1.2% to 4.4% of the general population. Given the clinical profile of the newer antiepileptic agents, it is likely their usage will increase in the coming years, thus increasing the emergency physician's exposure to these medications and their side effects. Several of these side effects can have high morbidity, such as the aplastic anemia and hepatotoxicity caused by felbamate, and the Stevens-Johnson syndrome associated with lamotrigine. Overdoses of these medications also could increase, as will our knowledge of recognizing and managing them. The clinical spectrum of the newer medications is the treatment of partial seizures. None of the newer medications can be orally loaded nor are they available in an i.v. preparation. Serum drug levels are not available in most institutions and are not routinely measured in the ED. The new preparations of phenytoin, diazepam, and valporic acid add increased efficiency in drug administration, providing a new method for prehospital treatment of seizures and a more tolerable means of administration in the ED.
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Affiliation(s)
- Y Yoon
- Department of Emergency Medicine, Mount Sinai School of Medicine, New York, New York, USA
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Benedetti MS. Enzyme induction and inhibition by new antiepileptic drugs: a review of human studies. Fundam Clin Pharmacol 2000; 14:301-19. [PMID: 11030437 DOI: 10.1111/j.1472-8206.2000.tb00411.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The aim of this paper is to review a number of new antiepileptic agents (i.e. felbamate, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tiagabine, topiramate, vigabatrin and zonisamide) for their inducing and/or inhibitory properties in humans, mainly considering the interactions where they are involved as the cause rather than the object of such interactions. Two aspects have been particularly taken into account: the changes or absence of changes in plasma/serum concentrations of concomitant drugs and the direct or indirect evidence of induction, inhibition or lack of effect on the six major human hepatic CYP isozymes (CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and CYP3A4), as well as on other CYP isozymes or enzyme systems. Felbamate clearly affects the pharmacokinetics of a number of drugs, generally increasing but also decreasing their concentrations. It induces enzymes such as CYP3A4 and inhibits enzymes such as CYP2C19 and those of the beta-oxidation pathway. Topiramate is not devoid of potential interaction properties: it decreases the plasma concentrations of ethinylestradiol, induces CYP3A4 and inhibits CYP2C19. For oxcarbazepine, no inhibitory, only inductive effects have been observed thus far. Felbamate. topiramate and oxcarbazepine may induce the metabolism of steroidal oral contraceptives. In this respect, tiagabine has been studied at a rather low dose. Pharmacodynamic or pharmacokinetic interaction seems to exist between lamotrigine and carbamazepine. Lamotrigine appears to be a weak inducer of UGTs, whereas induction of CYP3A4 seems improbable as the compound does not change the concentrations of oral contraceptives or the urinary excretion of 6beta-hydroxycortisol. Zonisamide has very peculiar pharmacokinetics and an extensive metabolism. Additional information on its enzyme inducing or inhibiting properties would be necessary, as data so far collected on its effect on the pharmacokinetics of other drugs are conflicting. Gabapentin, vigabatrin and in particular levetiracetam appear to be devoid of significant enzyme inducing or inhibiting properties.
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Kato Y, Fujii T, Mizoguchi N, Takata N, Ueda K, Feldman MD, Kayser SR. Potential interaction between ritonavir and carbamazepine. Pharmacotherapy 2000; 20:851-4. [PMID: 10907977 DOI: 10.1592/phco.20.9.851.35206] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Ritonavir (RTV), a protease inhibitor, and carbamazepine (CBZ), an anticonvulsant, were administered concurrently to a patient who had human immunodeficiency virus infection and epilepsy. The combination resulted in elevated serum concentrations of CBZ, with accompanying vomiting, vertigo, and transient liver dysfunction. After discontinuing RTV and reducing the dosage of CBZ, the serum concentration of CBZ returned to the optimal range, symptoms subsided, and liver function returned to baseline. Carbamazepine is metabolized in the liver to a large extent by the cytochrome P450 (CYP) system, especially CYP3A4, 2C8, and 1A2, whereas RTV is metabolized primarily by CYP3A and is a potent inhibitor of this enzyme. Careful clinical monitoring may help prevent adverse drug interactions when these drugs are administered concurrently.
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Affiliation(s)
- Y Kato
- Department of Pediatrics, Hiroshima University Medical Hospital, Japan
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Abstract
Clinical success with an antiepileptic drug (AED) depends primarily on its efficacy and tolerability. Clinicians also need to have a basic understanding of an AED's pharmacokinetic characteristics, particularly those affecting the potential for drug interactions such as hepatic enzyme inhibition or induction and protein-binding displacement. Successful treatment may be complicated by pharmacokinetic characteristics such as a short half-life, nonlinear kinetics, and active metabolites. Pharmacokinetic characteristics that make a drug easy to use may affect patient adherence. In general, newer AEDs such as topiramate (TPM) are simpler to use than traditional AEDs because they have more favorable pharmacokinetic characteristics and fewer drug interactions.
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Affiliation(s)
- W R Garnett
- Department of Pharmacy, School of Pharmacy, Medical College of Virginia Campus of Virginia Commonwealth University, Richmond 23298-0533, USA
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50
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Dooley JM, Camfield PR, Smith E, Langevin P, Ronen G. Topiramate in intractable childhood onset epilepsy--a cautionary note. Can J Neurol Sci 1999; 26:271-3. [PMID: 10563211 DOI: 10.1017/s0317167100000366] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVES To study the effectiveness and safety of topiramate in clinical practice, for a group of patients with childhood onset epilepsy. METHODS All patients treated with topiramate at the three study centers between November 1995 and December 31, 1997 were analyzed retrospectively, using a standardized study protocol. Data were gathered on demographic features, seizures response and medication related adverse events. RESULTS Eighty-seven patients were treated with topiramate. Over 90% seizure reduction was achieved in 8 (9%) patients, 50%-90% in 21 (24%), < 50% in 54 (62%) patients. Four patients (5%) had a deterioration in seizure control. Adverse events required topiramate discontinuation in 36 (41%). Of these 27 (31%) complained of unacceptable cognitive dulling. The rate of dose escalation and final dose in mg/kg were similar in those who remained on topiramate and those who were intolerant because of cognitive side effects. CONCLUSIONS Although topiramate resulted in > 50% seizure reduction in 29 (33%) of this group of patients with difficult epilepsy, its usefulness was limited by a high incidence of adverse effects. Adverse events prevented ongoing therapy for 36 (41%) and cognitive dulling resulted in topiramate discontinuation by 27 (31%) of the group.
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Affiliation(s)
- J M Dooley
- Neurology Division, IWK-Grace Health Centre, Halifax, Nova Scotia, Canada
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