Failure to detect amphetamine or 1-amino-3-phenlypropane in humans or ratsreceiving the MAO inhibitor tranylcypromine

Background: There have been conflicting reports in the literature about whe ther or not tranylcypromine is metabolized to amphetamine. In the current r eport, we investigated this possible route of metabolism in both rats and h umans. Body fluid samples from patients and rats and brain, liver and heart samples from rats were analyzed for levels of amphetamine and 1-amino-3-ph enylpropane, another potential product of cleavage of the cyclopropyl ring of tranylcypromine after administration of tranylcypromine. Extracted sampl es were reacted with pentofluorobenzenesulfonyl chloride and analyzed using electron-capture gas chromatography. Results: Amphetamine or 1-amino-3-phe nylpropane were not found in any of the samples, indicating that opening of the cyclopropyl ring of tranylcypromine is not a significant route of meta bolism for this drug at usual doses. Limitations: The assay procedure did n ot permit analysis of 1-amino-2-phenylpropane (another possible product of cleavage of the cyclopropyl ring of tranylcypromine) or of N-methylamphetam ine. Conclusions: These studies support the growing body of evidence indica ting that opening of the cyclopropyl ring of tranylcypromine to form amphet amine, a drug of abuse, is not significant at usual doses of tranylcypromin e. (C) 2000 Elsevier Science B.V. All rights reserved.