[Determination and comparison of the plasma and urine concentrations in men given tranylcypromine stereoisomers].

The (+) and (-)isomers of DL-trans-2-phenylcyclopropylamine (tranylcypromine, Parnate, Jatrosom) were tested under cross-over conditions on 10 volunteers. (-)Tranylcypromine entered blood circulation more rapidly, reached significantly higher concentrations and was metabolized more slowly than (+)tranylcypromine. These results indicate a difference in the pharmacokinetics of the tranylcypromine isomers. In the urine collected over a period of 24 h the excretion of unmetabolized (4)tranylcypromine was lower probably resulting from the greater metabolization rate of this isomer. There is a conformity between the findings in plasma and urine.