Pargyline was first described in 1960[9][16][17] and was introduced for medical use in 1963.[18] It was available in the United States and the United Kingdom.[18][2][5] The clinical use of pargyline was limited due to its side effects and interactions.[1] The drug remained available in the United States as late as 2000.[5] However, it was fully discontinued worldwide by 2007.[19]
Pargyline is used as an antihypertensive agent in the treatment of hypertension (high blood pressure).[1] The dosage was 12.5 to 200mg per day.[1][12] Its onset of action is slow and several weeks of continuous administration are required for the effects to develop fully upon initiation of treatment.[1][12] The decrease in blood pressure with pargyline is described as impressive and is especially strong when standing.[1][12] However, the blood pressure decrease with pargyline is often difficult to control adequately.[1]
Pargyline is a non-selective and irreversiblemonoamine oxidase inhibitor (MAOI), or an inhibitor of the monoamine oxidase (MAO) enzyme.[6] This enzyme is involved in the metabolism of the monoamine neurotransmittersserotonin, norepinephrine, and dopamine.[6][26] Pargyline is said to have slight preference or selectivity for inhibition of MAO-B over MAO-A (IC50Tooltip half-maximal inhibitory concentration = 8.20nM and 11.52nM, respectively).[6][27][28][29] Using rodent systems however, pargyline showed 2- to 356-fold selectivity for MAO-B inhibition over MAO-A inhibition in different studies (compared to 16- to 6401-fold selectivity with selegiline).[30] In relation to the preceding, pargyline has been referred to as a so-called semi-selective MAO-B inhibitor.[31][32] It has also been found to show some selectivity for MAO-B inhibition with a single dose but results in non-selective inhibition with continuous administration.[32]
Pargyline produces its antihypertensive effects via MAO inhibition.[9][10] However, the exact mechanism of action by which this occurs is unclear.[9][10][11][12] Pargyline and other MAOIs inhibit the metabolism of norepinephrine and cause accumulation of norepinephrine in the heart, brain, and other adrenergic tissues.[9][10][11][12] Some possibilities include diminished responsiveness to norepinephrine via increased norepinephrine levels in blood vessels and blockade blockade of the release of norepinephrine from peripheralsympatheticneurons.[9][1][12] Another possibility is that pargyline increases levels of false neurotransmitters like octopamine and tyramine, which are weaker pressor agents than norepinephrine.[9][10][1][33] However, the involvement of octopamine in the hypotensive effects of pargyline and other MAOIs is uncertain.[9][1][33] Yet another possibility is that the hypotensive effects may be due to accumulation of N-acetylserotonin, which shows antihypertensive effects in animals.[9][34] As of 2018, the precise mechanism of the hypotensive effects of MAOIs still remains unresolved.[9]
Pargyline is the generic name of the drug and its INNTooltip International Nonproprietary Name, BANTooltip British Approved Name, and DCFTooltip Dénomination Commune Française, while its USANTooltip United States Adopted Name and BANMTooltip British Approved Name in the case of the hydrochloridesalt is pargyline hydrochloride.[4][5][13] The drug is also known by the developmental code name MO-911.[26] Marketed brand names of pargyline have included Eutonyl and Eutron.[4][5][13]
^ abcdefghijkFinberg JP (August 2014). "Update on the pharmacology of selective inhibitors of MAO-A and MAO-B: focus on modulation of CNS monoamine neurotransmitter release". Pharmacology & Therapeutics. 143 (2): 133–152. doi:10.1016/j.pharmthera.2014.02.010. PMID24607445.
^ abcdeKline NS, Cooper TB (1980). "Monoamine Oxidase Inhibitors as Antidepressants". Psychotropic Agents. Handbook of Experimental Pharmacology. Vol. 55 / 1. Berlin, Heidelberg: Springer Berlin Heidelberg. pp. 369–397. doi:10.1007/978-3-642-67538-6_17. ISBN978-3-642-67540-9.
^ abcdefghijkTipton KF (November 2018). "90 years of monoamine oxidase: some progress and some confusion". Journal of Neural Transmission. 125 (11): 1519–1551. doi:10.1007/s00702-018-1881-5. PMID29637260.
^ abcdeAbrams WB (February 1969). "The mechanisms of action of antihypertensive drugs". Diseases of the Chest. 55 (2): 148–159. doi:10.1378/chest.55.2.148. PMID4887212.
^ abcMcDonald RH (September 1988). "The evolution of current hypertension therapy". The American Journal of Medicine. 85 (3B): 14–18. doi:10.1016/0002-9343(88)90344-0. PMID3048093.
^ abFowler CJ, Oreland L, Callingham BA (June 1981). "The acetylenic monoamine oxidase inhibitors clorgyline, deprenyl, pargyline and J-508: their properties and applications". The Journal of Pharmacy and Pharmacology. 33 (6): 341–347. doi:10.1111/j.2042-7158.1981.tb13800.x. PMID6115003.
^ abFord RV (September 1961). "Clinical and pharmacologic observations on a monoamine oxidase inhibitor (pargyline hydrochloride) in hypertension". Current Therapeutic Research, Clinical and Experimental. 3: 378–382. PMID13700727.
^ abBryant JM, Torosdag S, Schvartz N, Fletcher L, Fertig H, Schwartz MS, et al. (October 1961). "Antihypertensive properties of pargyline hydrochloride. New non-hydrazine monoamine oxidase inhibitor compared with sulphonamide diuretics". JAMA. 178: 406–409. doi:10.1001/jama.1961.73040430005010. PMID13874134.
^ abcdeGreen AR, Haddad PM, Aronson JK (August 2018). "Marketing medicines: charting the rise of modern therapeutics through a systematic review of adverts in UK medical journals (1950-1980)". British Journal of Clinical Pharmacology. 84 (8): 1668–1685. doi:10.1111/bcp.13549. PMC6046508. PMID29442380. Two more novel antihypertensives appeared in the advertising pages of the BMJ before the end of 1963. The first was pargyline, brand name Eutonyl, marketed by Abbott. The company had observed that this non-hydrazine MAO inhibitor had, in common with other MAO inhibitors, a hypotensive effect. The text suggested that the drug, when combined with their other drug Enduron (methyclothiazide), allowed a lowering of the dose of Eutonyl (BMJ, 12-10-63). The selling point of Eutonyl was 'lowers blood pressure, brightens emotional outlook'.
^ abcRagheb M (1981). "Drug interactions in psychiatric practice". International Pharmacopsychiatry. 16 (2): 92–118. doi:10.1159/000468482. PMID6120917. The administration of methyldopa to mice pretreated with the MAOI pargyline resulted in central nervous system excitation [van Rossum and Hurkmans, 1963]. Warning was then issued against the concomitant use of MAOIs and methyldopa in humans [van Rossum 1963]. A case of visual hallucinations was reported following the administration of methyldopa to a patient receiving pargyline [Paykel, 1966].
^ abcdHurkmans JA (August 1963). "Reversal of the effect of α-methyldopa by monoamine oxidase inhibitors". The Journal of Pharmacy and Pharmacology. 15 (1): 493–499. doi:10.1111/j.2042-7158.1963.tb12824.x. PMID14059015.
^Fisar Z, Hroudová J, Raboch J (2010). "Inhibition of monoamine oxidase activity by antidepressants and mood stabilizers". Neuro Endocrinology Letters. 31 (5): 645–656. PMID21200377.
^Murphy DL, Karoum F, Pickar D, et al. (1998). "Differential trace amine alterations in individuals receiving acetylenic inhibitors of MAO-A (Clorgyline) or MAO-B (Selegiline and pargyline)". In Finberg JP, Youdim MB, Riederer P, Tipton KF (eds.). MAO — the Mother of all Amine Oxidases. Journal of Neural Transmission Supplementum. Vol. 52. pp. 39–48. doi:10.1007/978-3-7091-6499-0_5. ISBN978-3-211-83037-6. PMID9564606.
^Paul W, Szelenyi I (1993). "Appendix I: Chemical Structures and Pharmacological Features of MAO-B Inhibitors". In Szelenyi I (ed.). Inhibitors of Monoamine Oxidase B: Pharmacology and Clinical Use in Neurodegenerative Disorders. Milestones in Drug Therapy. Basel: Birkhäuser Basel. pp. 339–358. ISBN978-3-0348-6349-0. ISSN2296-6056.
^ abcMagyar K (1993). "Pharmacology of Monoamine Oxidase Type B Inhibitors". Milestones in Drug Therapy (in German). Basel: Birkhäuser Basel. p. 125–143. doi:10.1007/978-3-0348-6348-3_6. ISBN978-3-0348-6349-0. ISSN2296-6056. Pargyline was earlier considered to be a selective inhibitor of MAO-B. In an appropriate dose and after a single administration, pargyline shows some selectivity to MAO-B, but when it is given chronically it induces a non-selective inhibition of both enzyme types [38]. [...] selegiline, in contrast to pargyline and tranylcypromine, blocks the release of NA from the storage vesicles of the rat heart [7, 66]. [...] The effects of various MAO-B inhibitors on rabbit arterial strip response to T A were studied recently [Ill]. In addition to selegiline, MDL-72145, Ro 16-6491, AGN-1135, J-508, U-1424, TZ-650 were included in these studies. All of the MAO-B selective inhibitors except selegiline potentiated the effect of T A on the pulmonary artery strip, and similar results were also obtained in anesthetized cats and rats in vivo regarding blood pressure response to T A [ 112]. Tranylcypromine, pargyline, and clorgyline were also shown to be strong potentiators of TA both in vitro and in vivo. Selegiline was the only exception, which indicates that the lack ofT A potentiation is not a general characteristic of MAO-B inhibitors.
^ abHicks TP (April 1977). "The possible role of octopamine as a synaptic transmitter: a review". Canadian Journal of Physiology and Pharmacology. 55 (2): 137–152. doi:10.1139/y77-022. PMID17454.
^Oxenkrug GF (1999). "Antidepressive and antihypertensive effects of MAO-A inhibition: role of N-acetylserotonin. A review". Neurobiology. 7 (2): 213–224. PMID10591054.
^ abBarbelivien A, Nyman L, Haapalinna A, Sirviö J (June 2001). "Inhibition of MAO-A activity enhances behavioural activity of rats assessed using water maze and open arena tasks". Pharmacology & Toxicology. 88 (6): 304–312. doi:10.1034/j.1600-0773.2001.880604.x. PMID11453370.
^Spencer PS (1977). "Review of the pharmacology of existing antidepressants". British Journal of Clinical Pharmacology. 4 (Suppl 2): 57S–68S. doi:10.1111/j.1365-2125.1977.tb05761.x. PMC1429129. PMID334231. The MAO inhibitors are subdivided, not only according to structure (hydrazine or non-hydrazine) but also according to the presence or absence of inherent amphetamine-like activity. Thus high doses of iproniazid, pheniprazine, phenelzine and tranylcypromine directly increase motor activity, whereas nialamide and pargyline do not.
^Kammerer RC, Amiri B, Cho AK (April 1979). "Inhibition of uptake of catecholamines by benzylamine derivatives". Journal of Medicinal Chemistry. 22 (4): 352–355. doi:10.1021/jm00190a004. PMID430475.
^Sourkes TL, Missala K (January 1977). "Action of inhibitors on monoamine and diamine metabolism in the rat". Canadian Journal of Biochemistry. 55 (1): 56–59. doi:10.1139/o77-010. PMID402175.
^Hsu LL (February 1984). "Pineal aryl acylamidase: effects of melatonin, serotonin-related compounds, beta-carbolines, RO4-4602 and antidepressants". Research Communications in Chemical Pathology and Pharmacology. 43 (2): 223–234. PMID6709961.
^Boudíková-Girard B, Scott MC, Weinshilboum R (September 1993). "Histamine N-methyltransferase: inhibition by monoamine oxidase inhibitors". Agents and Actions. 40 (1–2): 1–10. doi:10.1007/BF01976745. PMID8147263.
^Yen TT, Dalló J, Knoll J (1982). "The aphrodisiac effect of low doses of (-) deprenyl in male rats". Pol J Pharmacol Pharm. 34 (5–6): 303–308. PMID6821215.
^ abc"Pargyline". PubChem. U.S. National Library of Medicine. Retrieved 11 August 2024.
^ abKaroum F (1985). "The Effects of Pargyline, Clorgyline, Deprenyl and their Metabolites on Rat Peripheral and Central Biogenic Amines: A Comparison between Changes in Urine Excretion and Brain Concentrations". Neuropsychopharmacology of the Trace Amines. Totowa, NJ: Humana Press. pp. 285–293. doi:10.1007/978-1-4612-5010-4_30. ISBN978-1-4612-9397-2.
^Spector S, Hirsch C, Brodie B (1963). "Association of behavoural effects of pargyline, a non-hydrazide mao inhibitor with increase in brain norepinephrine". International Journal of Neuropharmacology. 2 (1–2): 81–93. doi:10.1016/0028-3908(63)90037-6.
^ abcBaker GB, Urichuk LJ, McKenna KF, Kennedy SH (June 1999). "Metabolism of monoamine oxidase inhibitors". Cellular and Molecular Neurobiology. 19 (3): 411–426. doi:10.1023/a:1006901900106. PMID10319194.
^Hall DW, Logan BW, Parsons GH (June 1969). "Further studies on the inhibition of monoamine oxidase by M and B 9302 (clorgyline). I. Substrate specificity in various mammalian species". Biochemical Pharmacology. 18 (6): 1447–1454. doi:10.1016/0006-2952(69)90258-5. PMID5799116.
^Hall DW, Logan BW (August 1969). "Further studies on the inhibition of monoamine oxidase by M & B 9302 (clorgyline). II. Comparison of M & B 9302 inhibition with that of iproniazid". Biochemical Pharmacology. 18 (8): 1955–1959. doi:10.1016/0006-2952(69)90291-3. PMID5811628.
^Oltman JE, Friedman S (November 1963). "Pargyline in the Treatment of Depressive Illnesses". The American Journal of Psychiatry. 120 (5): 493–494. doi:10.1176/ajp.120.5.493. PMID14054108.
^Saunders JC (July 1963). "Treatment of hospitalized depressed and schizophrenic patients with monoamine oxidase inhibitors: including reflections on pargyline". Annals of the New York Academy of Sciences. 107 (3): 1081–1089. Bibcode:1963NYASA.107.1081S. doi:10.1111/j.1749-6632.1963.tb13351.x. PMID13986821.
^Janecek J, Schiele BC, Vestre ND (1963). "Pargyline and Tranylcypromine in the Treatment of Hospitalized Depressed Patients". The Journal of New Drugs. 3 (5): 309–316. doi:10.1002/j.1552-4604.1963.tb00084.x. PMID14089807.
^Stern FH (July 1963). "Pargyvine hydrochloride: a new agent for the control of hypertension and mental depression". Journal of the American Geriatrics Society. 11 (7): 670–672. doi:10.1111/j.1532-5415.1963.tb02616.x. PMID13983943.
^Ayd FJ (1965). "A clinical evaluation of pargyline hydrochloride (Eutonyl) in the management of mental depression". International Journal of Neuropsychiatry. 1: 233–238. PMID14309088.