Aside from being an active metabolite of selegiline, DMS itself has been studied clinically.[1][10][3] A single 10mg oral dose of DMS inhibited platelet MAO-B activity by 68 ± 16%, relative to 94 ± 9% with a single 10mg dose of selegiline.[1][2][3] Subsequently, platelet MAO-B activity returned to baseline after 2weeks.[1][2][3] Hence, although less potent than selegiline, DMS is also an effective MAO-B inhibitor.[1][10][3]
DMS has been found to be 60-fold less potent than selegiline as an MAO-B inhibitor in vitro.[1][2][11] However, it was only 3-fold less potent than selegiline orally in vivo in rats with repeated administration.[1][2][9][11] In other research, DMS was 6-fold less potent than selegiline in inhibition of platelet MAO-B activity.[1][12]
Selegiline and DMS were compared in a clinical study in which 10mg of each drug was administered orally.[3] DMS showed 27-fold higher peak levels and 33-fold higher area-under-the-curve levels than selegiline in this study, suggesting that it has much greater oral bioavailability than selegiline.[3]
Selegiline is metabolized into DMS in the liver.[20] With use of oral selegiline in humans, 86% of a dose is excreted in urine, with 1.1% of this being DMS, 59.2% being levomethamphetamine, and 26.3% being levoamphetamine.[20] Levoamphetamine is formed with selegiline from both DMS and levomethamphetamine.[20][21] However, levoamphetamine is only a minor metabolite of levomethamphetamine (2–3%).[21] As a metabolite of selegiline, DMS has an elimination half-life ranging from 2.6 to 11hours.[1] The half-lives of both selegiline and DMS increase with continuous use of selegiline.[1]
^Smith & Davis (1977) reviewed 11clinical studies of dextroamphetamine and levoamphetamine including doses and potency ratios in terms of a variety of psychological and behavioral effects.[8] The summaries of these studies are in Table 1 of the paper.[8]
^ abcdefghiHeinonen EH, Anttila MI, Lammintausta RA (December 1994). "Pharmacokinetic aspects of l-deprenyl (selegiline) and its metabolites". Clinical Pharmacology and Therapeutics. 56 (6 Pt 2): 742–749. doi:10.1038/clpt.1994.204. PMID7995016.
^ abcdefghijklmnHeinonen EH, Anttila MI, Karnani HL, Nyman LM, Vuorinen JA, Pyykkö KA, et al. (July 1997). "Desmethylselegiline, a metabolite of selegiline, is an irreversible inhibitor of monoamine oxidase type B in humans". Journal of Clinical Pharmacology. 37 (7): 602–609. doi:10.1002/j.1552-4604.1997.tb04342.x. PMID9243353.
^ abcMiklya I (June 2014). "Essential difference between the pharmacological spectrum of (-)-deprenyl and rasagiline". Pharmacological Reports. 66 (3): 453–458. doi:10.1016/j.pharep.2013.11.003. PMID24905523.
^ abcdSmith RC, Davis JM (June 1977). "Comparative effects of d-amphetamine, l-amphetamine, and methylphenidate on mood in man". Psychopharmacology. 53 (1): 1–12. doi:10.1007/BF00426687. PMID407607.
^ abcdeFoley P, Gerlach M, Youdim MB, Riederer P (January 2000). "MAO-B inhibitors: multiple roles in the therapy of neurodegenerative disorders?". Parkinsonism & Related Disorders. 6 (1): 25–47. doi:10.1016/s1353-8020(99)00043-7. PMID18591148.
^ abBorbe HO, Niebch G, Nickel B (1990). "Kinetic evaluation of MAO-B-activity following oral administration of selegiline and desmethyl-selegiline in the rat". Amine Oxidases and Their Impact on Neurobiology. Journal of Neural Transmission. Supplementum. Vol. 32. pp. 131–137. doi:10.1007/978-3-7091-9113-2_18. ISBN978-3-211-82239-5. PMID2128496.
^Mahmood I, Neau SH, Mason WD (July 1994). "An enzymatic assay for the MAO-B inhibitor selegiline in plasma". Journal of Pharmaceutical and Biomedical Analysis. 12 (7): 895–899. doi:10.1016/0731-7085(93)e0021-e. PMID7981318.
^Knoll J (February 1998). "(-)Deprenyl (selegiline), a catecholaminergic activity enhancer (CAE) substance acting in the brain". Pharmacology & Toxicology. 82 (2): 57–66. doi:10.1111/j.1600-0773.1998.tb01399.x. PMID9498233.
^ abMytilineou C, Leonardi EK, Radcliffe P, Heinonen EH, Han SK, Werner P, et al. (February 1998). "Deprenyl and desmethylselegiline protect mesencephalic neurons from toxicity induced by glutathione depletion". The Journal of Pharmacology and Experimental Therapeutics. 284 (2): 700–706. PMID9454817.
^ abcMytilineou C, Radcliffe PM, Olanow CW (January 1997). "L-(-)-desmethylselegiline, a metabolite of selegiline [L-(-)-deprenyl], protects mesencephalic dopamine neurons from excitotoxicity in vitro". Journal of Neurochemistry. 68 (1): 434–436. doi:10.1046/j.1471-4159.1997.68010434.x. PMID8978757.
^ abcTatton WG, Chalmers-Redman RM (December 1996). "Modulation of gene expression rather than monoamine oxidase inhibition: (-)-deprenyl-related compounds in controlling neurodegeneration". Neurology. 47 (6 Suppl 3): S171–S183. doi:10.1212/wnl.47.6_suppl_3.171s. PMID8959986.
^Gerlach M, Reichmann H, Riederer P (2012). "A critical review of evidence for preclinical differences between rasagiline and selegiline". Basal Ganglia. 2 (4): S9–S15. doi:10.1016/j.baga.2012.04.032.
^Tatton W, Chalmers-Redman R, Tatton N (May 2003). "Neuroprotection by deprenyl and other propargylamines: glyceraldehyde-3-phosphate dehydrogenase rather than monoamine oxidase B". Journal of Neural Transmission. 110 (5): 509–515. doi:10.1007/s00702-002-0827-z. PMID12721812.
^Dalvie D, Kalgutkar AS (2023). "Utilizing mechanistic organic chemistry training to study drug metabolism in preclinical drug discovery/development". Medicinal Chemistry Research. 32 (9): 1922–1932. doi:10.1007/s00044-023-03085-z. ISSN1054-2523.
^Flaherty P, Castagnoli K, Wang YX, Castagnoli N (November 1996). "Synthesis and selective monoamine oxidase B-inhibiting properties of 1-methyl-1,2,3,6-tetrahydropyrid-4-yl carbamate derivatives: potential prodrugs of (R)- and (S)-nordeprenyl". Journal of Medicinal Chemistry. 39 (24): 4756–4761. doi:10.1021/jm960477e. PMID8941389.
† References for all endogenous human TAAR1 ligands are provided at List of trace amines
‡ References for synthetic TAAR1 agonists can be found at TAAR1 or in the associated compound articles. For TAAR2 and TAAR5 agonists and inverse agonists, see TAAR for references.