{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,3]],"date-time":"2026-07-03T10:51:34Z","timestamp":1783075894740,"version":"3.54.6"},"reference-count":27,"publisher":"Wiley","issue":"10","license":[{"start":{"date-parts":[[2017,9,19]],"date-time":"2017-09-19T00:00:00Z","timestamp":1505779200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"funder":[{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["P50\u2010NS16308"],"award-info":[{"award-number":["P50\u2010NS16308"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000049","name":"National Institute on Aging","doi-asserted-by":"publisher","award":["R01\u2010AG026390"],"award-info":[{"award-number":["R01\u2010AG026390"]}],"id":[{"id":"10.13039\/100000049","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["accpjournals.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Pharmacotherapy"],"published-print":{"date-parts":[[2017,10]]},"abstract":"<jats:sec><jats:title>Objectives<\/jats:title><jats:p>To characterize and quantify the variability of serial gabapentin concentrations in elderly patients with epilepsy.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>This study included 83 patients (age \u2265 60 yrs) from an 18\u2010center randomized double\u2010blind double\u2010dummy parallel study from the Veterans Affairs Cooperative 428 Study. All patients were taking 1500 mg\/day gabapentin. Within\u2010person coefficient of variation (<jats:styled-content style=\"fixed-case\">CV<\/jats:styled-content>) in gabapentin concentrations, measured weekly to bimonthly for up to 52 weeks, then quarterly, was computed. Impact of patient characteristics on gabapentin concentrations (linear mixed model) and <jats:styled-content style=\"fixed-case\">CV<\/jats:styled-content> (linear regression) were estimated.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>A total of 482 gabapentin concentration measurements were available for analysis. Gabapentin concentrations and intrapatient <jats:styled-content style=\"fixed-case\">CV<\/jats:styled-content>s ranged from 0.5 to 22.6 \u03bcg\/ml (mean 7.9 \u03bcg\/ml, standard deviation [<jats:styled-content style=\"fixed-case\">SD<\/jats:styled-content>] 4.1 \u03bcg\/ml) and 2% to 79% (mean 27.9%, <jats:styled-content style=\"fixed-case\">SD<\/jats:styled-content> 15.3%), respectively, across all visits. Intrapatient <jats:styled-content style=\"fixed-case\">CV<\/jats:styled-content> was higher by 7.3% for those with a body mass index of \u2265 30 kg\/m<jats:sup>2<\/jats:sup> (coefficient = 7.3, p=0.04). <jats:styled-content style=\"fixed-case\">CV<\/jats:styled-content>s were on average 0.5% higher for each 1\u2010unit higher <jats:styled-content style=\"fixed-case\">CV<\/jats:styled-content> in creatinine clearance (coefficient = 0.5, p=0.03) and 1.2% higher for each 1\u2010hour longer mean time after dose (coefficient = 1.2, p=0.04).<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>Substantial intrapatient variability in serial gabapentin concentration was noted in elderly patients with epilepsy. Creatinine clearance, time of sampling relative to dose, and obesity were found to be positively associated with variability.<\/jats:p><\/jats:sec>","DOI":"10.1002\/phar.2012","type":"journal-article","created":{"date-parts":[[2017,8,12]],"date-time":"2017-08-12T03:26:45Z","timestamp":1502508405000},"page":"1197-1203","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Factors in Variability of Serial Gabapentin Concentrations in Elderly Patients with Epilepsy"],"prefix":"10.1002","volume":"37","author":[{"given":"Jeannine M.","family":"Conway","sequence":"first","affiliation":[{"name":"Experimental and Clinical Pharmacology College of Pharmacy, University of Minnesota Minneapolis Minnesota"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lynn E.","family":"Eberly","sequence":"additional","affiliation":[{"name":"Division of Biostatistics School of Public Health, University of Minnesota Minneapolis Minnesota"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joseph F.","family":"Collins","sequence":"additional","affiliation":[{"name":"VA Medical Center Perry Point Maryland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Flavia M.","family":"Macias","sequence":"additional","affiliation":[{"name":"University of Miami, School of Medicine Miami Florida"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R. Eugene","family":"Ramsay","sequence":"additional","affiliation":[{"name":"University of Miami, School of Medicine Miami Florida"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ilo E.","family":"Leppik","sequence":"additional","affiliation":[{"name":"Experimental and Clinical Pharmacology College of Pharmacy, University of Minnesota Minneapolis Minnesota"},{"name":"Department of Neurology University of Minnesota Minneapolis Minnesota"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Angela K.","family":"Birnbaum","sequence":"additional","affiliation":[{"name":"Experimental and Clinical Pharmacology College of Pharmacy, University of Minnesota Minneapolis Minnesota"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2017,9,19]]},"reference":[{"key":"e_1_2_6_2_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1528-1167.2008.01561.x"},{"key":"e_1_2_6_3_1","doi-asserted-by":"publisher","DOI":"10.1097\/00007691-197910000-00004"},{"key":"e_1_2_6_4_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1528-1157.1988.tb05801.x"},{"key":"e_1_2_6_5_1","doi-asserted-by":"publisher","DOI":"10.1097\/00007691-198612000-00009"},{"key":"e_1_2_6_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.eplepsyres.2012.02.014"},{"key":"e_1_2_6_7_1","doi-asserted-by":"publisher","DOI":"10.1097\/FTD.0b013e31811f3296"},{"key":"e_1_2_6_8_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.eplepsyres.2007.08.004"},{"key":"e_1_2_6_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.eplepsyres.2004.08.009"},{"key":"e_1_2_6_10_1","doi-asserted-by":"publisher","DOI":"10.1212\/01.WNL.0000052997.43492.E0"},{"key":"e_1_2_6_11_1","doi-asserted-by":"publisher","DOI":"10.1046\/j.1528-1157.2003.62202.x"},{"key":"e_1_2_6_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.eplepsyres.2004.04.006"},{"key":"e_1_2_6_13_1","doi-asserted-by":"publisher","DOI":"10.1023\/A:1018951214146"},{"key":"e_1_2_6_14_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0920-1211(00)00117-0"},{"key":"e_1_2_6_15_1","doi-asserted-by":"publisher","DOI":"10.1038\/clpt.1994.118"},{"key":"e_1_2_6_16_1","doi-asserted-by":"publisher","DOI":"10.1212\/01.WNL.0000167384.68207.3E"},{"key":"e_1_2_6_17_1","doi-asserted-by":"publisher","DOI":"10.1097\/00007691-199506000-00007"},{"key":"e_1_2_6_18_1","first-page":"S17","article-title":"Clinical pharmacokinetics of gabapentin","volume":"44","author":"McLean MJ","year":"1994","journal-title":"Neurology"},{"key":"e_1_2_6_19_1","doi-asserted-by":"publisher","DOI":"10.1159\/000180580"},{"key":"e_1_2_6_20_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2125.2008.03112.x"},{"key":"e_1_2_6_21_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1528-1157.1999.tb00743.x"},{"key":"e_1_2_6_22_1","doi-asserted-by":"publisher","DOI":"10.1097\/00007691-200412000-00008"},{"key":"e_1_2_6_23_1","doi-asserted-by":"crossref","first-page":"440","DOI":"10.1097\/FTD.0b013e31825ee389","article-title":"Pharmacokinetic variability of four new antiepileptic drugs, lamotrigine, levetiracetam, oxcarbazepine, and topiramate: a comparison of the impact of age and comedication","volume":"34","author":"Johannessen Landmark C","year":"2012","journal-title":"Ther Drug Monit"},{"key":"e_1_2_6_24_1","doi-asserted-by":"publisher","DOI":"10.1208\/s12248-016-0022-z"},{"key":"e_1_2_6_25_1","doi-asserted-by":"publisher","DOI":"10.1001\/jama.1989.03420220087032"},{"key":"e_1_2_6_26_1","doi-asserted-by":"publisher","DOI":"10.1016\/0920-1211(95)00051-8"},{"key":"e_1_2_6_27_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1532-5415.1981.tb01766.x"},{"key":"e_1_2_6_28_1","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.50.4.1146"}],"container-title":["Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fphar.2012","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/accpjournals.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/phar.2012","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,21]],"date-time":"2025-10-21T12:19:00Z","timestamp":1761049140000},"score":1,"resource":{"primary":{"URL":"https:\/\/accpjournals.onlinelibrary.wiley.com\/doi\/10.1002\/phar.2012"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,9,19]]},"references-count":27,"journal-issue":{"issue":"10","published-print":{"date-parts":[[2017,10]]}},"alternative-id":["10.1002\/phar.2012"],"URL":"https:\/\/doi.org\/10.1002\/phar.2012","archive":["Portico"],"relation":{},"ISSN":["0277-0008","1875-9114"],"issn-type":[{"value":"0277-0008","type":"print"},{"value":"1875-9114","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,9,19]]},"assertion":[{"value":"2017-09-19","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}