Posaconazole-Induced Topiramate Toxicity
Authors: Deborah Marriott, Russell Levy, Tom Doyle, John Ray
Journal: Annals of Internal Medicine (2009)

Letters21 July 2009Posaconazole-Induced Topiramate ToxicityDeborah Marriott, MBBS, BSc(Med), Russell Levy, BPharm, MClinPharm, Tom Doyle, MBBS, and John Ray, PhDDeborah Marriott, MBBS, BSc(Med)From St. Vincent's Hospital, Darlinghurst, NSW 2010, Australia, and SydPath, Darlinghurst, NSW 2010, Australia.Search for more papers by this author, Russell Levy, BPharm, MClinPharmFrom St. Vincent's Hospital, Darlinghurst, NSW 2010, Australia, and SydPath, Darlinghurst, NSW 2010, Australia.Search for more papers by this author, Tom Doyle, MBBSFrom St. Vincent's Hospital, Darlinghurst, NSW 2010, Australia, and SydPath, Darlinghurst, NSW 2010, Australia.Search for more papers by this author, and John Ray, PhDFrom St. Vincent's Hospital, Darlinghurst, NSW 2010, Australia, and SydPath, Darlinghurst, NSW 2010, Australia.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-151-2-200907210-00018 SectionsAboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail Background: Posaconazole is an azole antifungal agent that is excreted primarily unchanged in the feces (77%). It is an inhibitor of CYP450 3A4 but is predominantly metabolized by glucuronidation and thus believed to have a narrow drug interaction profile compared with other azoles (1). Topiramate is a novel anticonvulsant that is said to be 55% to 97% excreted unchanged by the kidneys, with the remainder undergoing hepatic metabolism via CYP450. Symptoms of topiramate toxicity include drowsiness, lethargy, dizziness, vertigo, agitation, and confusion (2).Objective: To report a case of suspected posaconazole-induced topiramate toxicity.Case Report: A 48-year-old white man underwent ...References1. Wexler D, Courtney R, Richards W, Banfield C, Lim J, Laughlin M. Effect of posaconazole on cytochrome P450 enzymes: a randomized, open-label, two-way crossover study. Eur J Pharm Sci. 2004;21:645-53. [PMID: 15066665] CrossrefMedlineGoogle Scholar2. Lofton AL, Klein-Schwartz W. Evaluation of toxicity of topiramate exposures reported to poison centers. Hum Exp Toxicol. 2005;24:591-5. [PMID: 16323576] CrossrefMedlineGoogle Scholar3. Holland ML, Uetz JA, Ng KT. Automated capillary gas chromatographic assay using flame ionization detection for the determination of topiramate in plasma. J Chromatogr. 1988;433:276-81. [PMID: 3235557] CrossrefMedlineGoogle Scholar4. Contin M, Riva R, Albani F, Avoni P, Baruzzi A. Topiramate therapeutic monitoring in patients with epilepsy: effect of concomitant antiepileptic drugs. Ther Drug Monit. 2002;24:332-7. [PMID: 12021622] CrossrefMedlineGoogle Scholar5. Wikinski S. [Pharmacokinetic mechanisms underlying resistance in psychopharmacological treatment. The role of P-glycoprotein]. Vertex. 2005;16:438-41. [PMID: 16314897] MedlineGoogle Scholar6. Latour P, Biraben A, Polard E, Bentué-Ferrer D, Beauplet A, Tribut O, et al. Drug induced encephalopathy in six epileptic patients: topiramate? valproate? or both? Hum Psychopharmacol. 2004;19:193-203. [PMID: 15079854] CrossrefMedlineGoogle Scholar Author, Article, and Disclosure InformationAffiliations: From St. Vincent's Hospital, Darlinghurst, NSW 2010, Australia, and SydPath, Darlinghurst, NSW 2010, Australia.Disclosures: None disclosed. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics Cited byAntifungal AgentsTopiramateValproic AcidCannabinoidsDrug Interactions with the Newer Antiepileptic Drugs (AEDs)—Part 2: Pharmacokinetic and Pharmacodynamic Interactions Between AEDs and Drugs Used to Treat Non-Epilepsy DisordersTopiramateValproic AcidPosaconazole Plasma Concentrations in Critically Ill PatientsAntiepileptic drugsSuivi thérapeutique pharmacologique du topiramate 21 July 2009Volume 151, Issue 2Page: 143KeywordsAmphotericinAntifungalsBlood plasmaBrain diseasesDrug interactionsDrugsPharmacokineticsToxicityVoriconazoleWeight loss ePublished: 21 July 2009 Issue Published: 21 July 2009 Copyright & PermissionsCopyright © 2009 by American College of Physicians. All Rights Reserved.PDF downloadLoading ...