In overdose, iprindole is much less toxic than most other TCAs and is considered relatively benign.[17] For instance, between 1974 and 1985, only two deaths associated with iprindole were recorded in the United Kingdom, whereas 278 were reported for imipramine, although imipramine is used far more often than iprindole.[10][17]
On account of these interactions, caution should be used when combining iprindole with other drugs.[3] As an example, when administered with amphetamine or methamphetamine, iprindole increases their brain concentrations and prolongs their terminal half-lives by 2- to 3-fold, strongly augmenting both their physiological effects and neurotoxicity in the process.[23][24][25]
Values are Ki (nM). The smaller the value, the more strongly the drug binds to the site.
Iprindole is unique compared to most other TCAs in that it is a very weak and negligible inhibitor of the reuptake of serotonin and norepinephrine and appears to act instead as a selective albeit weak antagonist of 5-HT2 receptors; hence its classification by some as "second-generation".[38][39][40] Additionally, iprindole has very weak/negligible antiadrenergic and anticholinergic activity and weak although possibly significant antihistamine activity; as such, side effects of iprindole are much less prominent relative to other TCAs, and it is well tolerated.[15] However, iprindole may not be as effective as other TCAs, particularly in terms of anxiolysis.[38][16] Based on animal research, the antidepressant effects of iprindole may be mediated through downstream dopaminergic mechanisms.[41]
The binding affinities of iprindole for various biological targets are presented in the table to the right.[26] It is presumed to act as an inhibitor or antagonist/inverse agonist of all sites. Considering the range of its therapeutic concentrations (e.g., 63–271 nM at 90 mg/day),[1] only the actions of iprindole on the 5-HT2 and histamine receptors might be anticipated to be of possible clinical significance.[1] However, it is unknown whether these actions are in fact responsible for the antidepressant effects of iprindole. The plasma protein binding of iprindole and hence its free percentage and potentially bioactive concentrations do not seem to be known.
Pharmacokinetics
Only one study appears to have evaluated the pharmacokinetics of iprindole.[1][42] A single oral dose of 60 mg iprindole to healthy volunteers has been found to achieve mean peak plasma concentrations of 67.1 ng/mL (236 nmol/L) after 2 to 4 hours.[1] The mean terminal half-life of iprindole was 52.5 hours, which is notably much longer than that of other TCAs like amitriptyline and imipramine.[1] Following chronic treatment with 90 mg/day iprindole for 3 weeks, plasma concentrations of the drug ranged between 18 and 77 ng/mL (63–271 nmol/L).[1] Theoretical steady-state concentrations should be reached by 99% within 15 to 20 days of treatment.[1]
Iprindole was developed by Wyeth and was marketed in 1967.[8][48]
Society and culture
Generic names
Iprindole is the English and Frenchgeneric name of the drug and its INNTooltip International Nonproprietary Name, USANTooltip United States Adopted Name, BANTooltip British Approved Name, and DCFTooltip Dénomination Commune Française, while iprindole hydrochloride is its BANMTooltip British Approved Name.[47][4][49] Its generic name in Spanish and German is iprindol while its generic name in Latin is iprindolum.[4] Iprindole was originally known unofficially as pramindole.[47][4]
Brand names
Iprindole has been marketed under the brand name Prondol by Wyeth in the United Kingdom and Ireland for the indication of major depressive disorder,[50] and has also been sold as Galatur and Tertran by Wyeth.[47]
Availability
Iprindole was previously available in the United Kingdom and Ireland[50] but seems to no longer be available for medical use in any country.[4]
References
^ abcdefghCaillé G, de Montigny C, Besner JG (1982). "Quantitation of iprindole in plasma by GLC". Biopharmaceutics & Drug Disposition. 3 (1): 11–17. doi:10.1002/bdd.2510030103. PMID7082775.
^Sisenwine SF, Tio CO, Ruelius HW (April 1979). "The disposition of [14C]iprindole in man, dog, miniature swine, rhesus monkey and rat". Xenobiotica; the Fate of Foreign Compounds in Biological Systems. 9 (4): 237–246. doi:10.3109/00498257909038726. PMID113942.
^ abcRotzinger S, Bourin M, Akimoto Y, Coutts RT, Baker GB (August 1999). "Metabolism of some "second"- and "fourth"-generation antidepressants: iprindole, viloxazine, bupropion, mianserin, maprotiline, trazodone, nefazodone, and venlafaxine". Cellular and Molecular Neurobiology. 19 (4): 427–442. doi:10.1023/A:1006953923305. PMID10379419. S2CID19585113.
^ abcRickels K, Chung HR, Csanalosi I, Sablosky L, Simon JH (September 1973). "Iprindole and imipramine in non-psychotic depressed out-patients". The British Journal of Psychiatry. 123 (574): 329–339. doi:10.1192/bjp.123.3.329. PMID4583430. S2CID23126539.
^Sedlock ML, Ravitch J, Edwards DJ (August 1985). "The effects of imipramine and iprindole on the metabolism of octopamine in the rat". Neuropharmacology. 24 (8): 705–708. doi:10.1016/0028-3908(85)90002-4. PMID3939325. S2CID39933551.
^Yamamoto T, Takano R, Egashira T, Yamanaka Y (November 1984). "Metabolism of methamphetamine, amphetamine and p-hydroxymethamphetamine by rat-liver microsomal preparations in vitro". Xenobiotica; the Fate of Foreign Compounds in Biological Systems. 14 (11): 867–875. doi:10.3109/00498258409151485. PMID6506759.
^Aspeslet LJ, Baker GB, Coutts RT, Torok-Both GA (1994). "The effects of desipramine and iprindole on levels of enantiomers of fluoxetine in rat brain and urine". Chirality. 6 (2): 86–90. doi:10.1002/chir.530060208. PMID8204417.
^Fuller RW, Baker JC, Molloy BB (February 1977). "Biological disposition of rigid analogs of amphetamine". Journal of Pharmaceutical Sciences. 66 (2): 271–272. doi:10.1002/jps.2600660235. PMID839428.
^ abRoth BL, Driscol J. "PDSP Ki Database". Psychoactive Drug Screening Program (PDSP). University of North Carolina at Chapel Hill and the United States National Institute of Mental Health. Retrieved 7 May 2022.
^ abcTatsumi M, Groshan K, Blakely RD, Richelson E (December 1997). "Pharmacological profile of antidepressants and related compounds at human monoamine transporters". European Journal of Pharmacology. 340 (2–3): 249–258. doi:10.1016/s0014-2999(97)01393-9. PMID9537821.
^ abcWander TJ, Nelson A, Okazaki H, Richelson E (December 1986). "Antagonism by antidepressants of serotonin S1 and S2 receptors of normal human brain in vitro". European Journal of Pharmacology. 132 (2–3): 115–121. doi:10.1016/0014-2999(86)90596-0. PMID3816971.
^ abPälvimäki EP, Roth BL, Majasuo H, Laakso A, Kuoppamäki M, Syvälahti E, Hietala J (August 1996). "Interactions of selective serotonin reuptake inhibitors with the serotonin 5-HT2c receptor". Psychopharmacology. 126 (3): 234–240. doi:10.1007/bf02246453. PMID8876023. S2CID24889381.
^ abcdRichelson E, Nelson A (July 1984). "Antagonism by antidepressants of neurotransmitter receptors of normal human brain in vitro". The Journal of Pharmacology and Experimental Therapeutics. 230 (1): 94–102. PMID6086881.
^Bylund DB, Snyder SH (July 1976). "Beta adrenergic receptor binding in membrane preparations from mammalian brain". Molecular Pharmacology. 12 (4): 568–580. PMID8699.
^ abcBaker GB, Greenshaw AJ (1988). "In Vitro and Ex Vivo Neurochemical Screening Procedures for Antidepressants, Neuroleptics, and Benzodiazepines". Analysis of Psychiatric Drugs. Vol. 10. pp. 327–378. doi:10.1385/0-89603-121-7:327. ISBN0-89603-121-7.
^Tsai BS, Yellin TO (November 1984). "Differences in the interaction of histamine H2 receptor antagonists and tricyclic antidepressants with adenylate cyclase from guinea pig gastric mucosa". Biochemical Pharmacology. 33 (22): 3621–3625. doi:10.1016/0006-2952(84)90147-3. PMID6150708.
^Kanba S, Richelson E (October 1983). "Antidepressants are weak competitive antagonists of histamine H2 receptors in dissociated brain tissue". European Journal of Pharmacology. 94 (3–4): 313–318. doi:10.1016/0014-2999(83)90420-x. PMID6140176.
^ abZis AP, Goodwin FK (September 1979). "Novel antidepressants and the biogenic amine hypothesis of depression. The case for iprindole and mianserin". Archives of General Psychiatry. 36 (10): 1097–1107. doi:10.1001/archpsyc.1979.01780100067006. PMID475543.
^Jaramillo J, Greenberg R (February 1975). "Comparative pharmacological studies on butriptyline and some related standard tricyclic antidepressants". Canadian Journal of Physiology and Pharmacology. 53 (1): 104–112. doi:10.1139/y75-014. PMID166748.
^Berettera C, Invernizzi R, Pulvirenti L, Samanin R (April 1986). "Chronic treatment with iprindole reduces immobility of rats in the behavioural 'despair' test by activating dopaminergic mechanisms in the brain". The Journal of Pharmacy and Pharmacology. 38 (4): 313–315. doi:10.1111/j.2042-7158.1986.tb04576.x. PMID2872301. S2CID27863022.
^ abSweetman SC, ed. (2009). Martindale: The Complete Drug Reference (36th ed.). London: Pharmaceutical Press. ISBN978-0-85369-840-1.
Further reading
de Montigny C (1982). "Iprindole: a cornerstone in the neurobiological investigation of antidepressant treatments". Modern Problems of Pharmacopsychiatry. Modern Trends in Pharmacopsychiatry. 18: 102–116. doi:10.1159/000406238. ISBN978-3-8055-3428-4. PMID6285182.