It may also act as a norepinephrine reuptake inhibitor at higher therapeutic doses. Compared to amphetamine, tranylcypromine shows low potency as a dopamine releasing agent, with even weaker potency for norepinephrine and serotonin release.Tranylcypromine has also been shown to inhibit the histone demethylase, BHC110/LSD1. Tranylcypromine inhibits this enzyme with an IC50 < 2 μM, thus acting as a small molecule inhibitor of histone demethylation with an effect to derepress the transcriptional activity of BHC110/LSD1 target genes. The clinical relevance of this effect is unknown. Tranylcypromine has been found to inhibit CYP46A1 at nanomolar concentrations. The clinical relevance of this effect is unknown. Pharmacokinetics
Tranylcypromine reaches its maximum concentration (tmax) within 1–2 hours. After a 20 mg dose, plasma concentrations reach at most 50-200 ng/mL. While its half-life is only about 2 hours, its pharmacodynamic effects last several days to weeks due to irreversible inhibition of MAO.Metabolites of tranylcypromine include 4-hydroxytranylcypromine, N-acetyltranylcypromine, and N-acetyl-4-hydroxytranylcypromine, which are less potent MAO inhibitors than tranylcypromine itself. Amphetamine was once thought to be a metabolite of tranylcypromine, but has not been shown to be.Tranylcypromine inhibits CYP2A6 at therapeutic concentrations. Chemistry
Synthesis
History
Tranylcypromine was originally developed as an analog of amphetamine. Although it was first synthesized in 1948, its MAOI action was not discovered until 1959.
Many different treatments have been attempted, with limited success in certain patients:  purine analogues (pentostatin, fludarabine, cladribine), chlorambucil, and various forms of combination chemotherapy regimens, including cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP), etoposide, bleomycin (VAPEC-B). Alemtuzumab (Campath), an anti-CD52 monoclonal antibody that attacks white blood cells, has been used in treatment with greater success than previous options. In one study of previously treated people with T-PLL, people who had a complete response to alemtuzumab survived a median of 16 months after treatment.Some patients who successfully respond to treatment also undergo stem cell transplantation to consolidate the response. Prognosis
T-PLL is an extremely rare aggressive disease, and patients are not expected to live normal lifespans. Before the recent introduction of better treatments, such as alemtuzumab, the median survival time was 7.5 months after diagnosis. More recently, some patients have survived five years and more, although the median survival is still low. Epidemiology
About four men are diagnosed with this disease for every three women. Despite its overall rarity, it is also the most common type of mature T cell leukemia. References


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