title: Detection of the novel metabolite ethylphenidate after methylphenidate overdose with alcohol coingestion.
abstract: Methylphenidate is the most commonly prescribed psychostimulant in clinical use today. Known methylphenidate metabolites include ritalinic acid, corresponding lactams, and p-hydroxymethylphenidate. Recent in vitro work using rat liver preparations has indicated that the methylphenidate ethyl ester, ethylphenidate, is formed upon incubation with ethanol. This report describes the first detection of ethylphenidate in human blood and liver samples obtained from two suicide victims who had overdosed on methylphenidate and coingested ethanol. Amounts of ethylphenidate detected in whole blood specimens in these two cases (8 ng/mL and 1 ng/mL, respectively) were small relative to methylphenidate and ritalinic acid concentrations. Nonetheless, given the high likelihood that methylphenidate and ethanol coingestion frequently occurs, the detection of ethylphenidate in humans warrants further investigation into the extent of its formation as well as into any associated toxicity in nonoverdose situations.
authors.affiliation: Department of Pharmaceutical Sciences, Medical University of South Carolina, Charleston 29425, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Markowitz
authors.forename: B K
authors.initials: BK
authors.lastname: Logan
authors.forename: F
authors.initials: F
authors.lastname: Diamond
authors.forename: K S
authors.initials: KS
authors.lastname: Patrick
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000009:adverse effects* / Q000097:blood; D004305:Dose-Response Relationship, Drug; D062787:Drug Overdose / Q000097:blood*; D004357:Drug Synergism; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008099:Liver / Q000378:metabolism; D008774:Methylphenidate / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000506:poisoning*; D013405:Suicide
chemical_list: D008774:Methylphenidate; C042400:ethylphenidate; C009189:ritalinic acid