ChEBI: (1R,2S)-tranylcypromine is a 2-phenylcyclopropan-1-amine that is the (1R,2S)-enantiomer of tranylcypromine. It is a conjugate base of a (1R,2S)-tranylcypromine(1+). It is an enantiomer of a (1S,2R)-tranylcypromine.
Tranylcypromine is a nonhydrazine, irreversible MAO inhibitor antidepressant agent that was designed as the
cyclopropyl analogue of amphetamine. Instead of exhibiting amphetamine-like stimulation, its
mechanism of action is nonselective, irreversible inhibition of MAO. Its onset of antidepressant action is more
rapid than for phenelzine. Tranylcypromine is well absorbed following oral administration.
Metabolism occurs via aromatic ring hydroxylation and N-acetylation. It is a competitive inhibitor of
CYP2C19 and CYP2D6 and a noncompetitive inhibitor of CYP 2C9. Most metabolism studies suggest that
tranylcypromine is not metabolized to amphetamine contrary to debate. Maximal MAO inhibition, however,
occurs within 5 to 10 days. The GI absorption of the tranylcypromine shows interindividual variation and may be biphasic in some individuals, achieving an initial peak within approximately 1 hour and a
secondary peak within 2 to 3 hours. It has been suggested that this apparent biphasic absorption in some
individuals may represent different absorption rates. Following discontinuance of tranylcypromine, the drug is
excreted within 24 hours. On withdrawal of tranylcypromine, MAO activity is recovered in 3 to 5 days
(possibly in up to 10 days). Concentrations of urinary tryptamine, an indicator of MAO-A inhibition return to
normal, however, within 72 to 120 hours.
