Detection of the novel metabolite ethylphenidate after methylphenidate overdose with alcohol coingestion

Methylphenidate is the most commonly prescribed psychostimulant in clinical use today. Known methylphenidate metabolites include ritalinic acid, corre sponding lactams, and p-hydroxymethylphenidate. Recent in vitro work using rad liver preparations has indicated that the methylphenidate ethyl ester, ethylphenidate, is formed upon incubation with ethanol. This report describ es the first detection of ethylphenidate in human blood and liver samples o btained from two suicide victims who had overdosed on methylphenidate and c oingested ethanol. Amounts of ethylphenidate detected in whole blood specim ens in these two cases (8 ng/mL and 1 ng/mL, respectively) were small relat ive to methylphenidate and ritalinic acid concentrations. Nonetheless, give n the high likelihood that methylphenidate and ethanol coingestion frequent ly occurs, the detection of ethylphenidate in humans warrants further inves tigation into the extent of ids formation as well as into any associated to xicity in nonoverdose situations.