Failure to detect amphetamine or 1-amino-3-phenylpropane in humans or rats receiving the MAO inhibitor tranylcypromine.

BACKGROUND

There have been conflicting reports in the literature about whether or not tranylcypromine is metabolized to amphetamine. In the current report, we investigated this possible route of metabolism in both rats and humans. 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-phenylpropane, another potential product of cleavage of the cyclopropyl ring of tranylcypromine after administration of tranylcypromine. Extracted samples were reacted with pentofluorobenzenesulfonyl chloride and analyzed using electron-capture gas chromatography.

RESULTS

Amphetamine or 1-amino-3-phenylpropane were not found in any of the samples, indicating that opening of the cyclopropyl ring of tranylcypromine is not a significant route of metabolism for this drug at usual doses.

LIMITATIONS

The assay procedure did not permit analysis of 1-amino-2-phenylpropane (another possible product of cleavage of the cyclopropyl ring of tranylcypromine) or of N-methylamphetamine.

CONCLUSIONS

These studies support the growing body of evidence indicating that opening of the cyclopropyl ring of tranylcypromine to form amphetamine, a drug of abuse, is not significant at usual doses of tranylcypromine.