Chlorphentermine
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Other names | 4-Chlorophentermine; 4-Chloro-α-methylamphetamine; 4-Chloro-α,α-dimethylphenethylamine |
Routes of administration | Oral |
Drug class | Serotonin releasing agent; Selective serotonin releasing agent; Appetite suppressant; Anorectic; Anorexic; Anorexiant |
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Elimination half-life | 40 hours[2]–5 days[3] |
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ECHA InfoCard | 100.006.651 |
Chemical and physical data | |
Formula | C10H14ClN |
Molar mass | 183.68 g·mol−1 |
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Chlorphentermine, sold under the brand names Apsedon, Desopimon, and Lucofen, is a serotonergic appetite suppressant of the amphetamine family. Developed in 1962, it is the para-chloro derivative of the better-known appetite suppressant phentermine, which is still in current use.
The drug acts as a highly selective serotonin releasing agent (SRA).[4] It is not a psychostimulant and has little or no misuse potential, but is classed as a Schedule III drug in the United States due mainly to its similarity to other appetite suppressants such as diethylpropion which have been more widely misused. It is no longer used due mainly to safety concerns, as it has a serotonergic effects profile similar to other withdrawn appetite suppressants such as fenfluramine and aminorex which were found to cause pulmonary hypertension and cardiac fibrosis following prolonged use.[5]
Chlorphentermine was first synthesized by 1954 and was subsequently developed in the early 1960s.[6][7][8][9] It remained on the market in the United States as late as 2004.[10]
Medical uses
[edit]Chlorphentermine was used as an appetite suppressant for purposes of weight loss in people with overweightness or obesity.[11][3][12]
Side effects
[edit]Side effects of chlorphentermine include impaired sleep, irritability, and gastrointestinal symptoms including dyspepsia.[11]
Euphoria is said to occasionally occur with chlorphentermine, but to a much lesser extent than with dextroamphetamine.[3] The drug does not produce amphetamine-like subjective effects in humans[13][14] and the psychostimulant effects of chlorphentermine are described as much less than those of dextroamphetamine.[3]
Pharmacology
[edit]Pharmacodynamics
[edit]Chlorphentermine acts as a selective serotonin releasing agent (SSRA).[15][16][17] The EC50 for monoamine release with chlorphentermine are 30.9 nM for serotonin, >10,000 nM for norepinephrine, and 2,650 nM for dopamine.[15][16][17] Although it is inactive as a norepinephrine releasing agent, it is a moderately potent norepinephrine reuptake inhibitor (IC50 = 451 nM; 15-fold lower than its EC50 value for serotonin release).[18][16] The activity of chlorphentermine as an SSRA is in contrast to phentermine, which acts as a selective norepinephrine and dopamine releasing agent (NDRA).[16][17]
In animals, chlorphentermine robustly and dose-dependently increases serotonin levels in the brain.[19][14] It also increases dopamine levels in the brain at high doses.[19][14] Whereas dextroamphetamine and phentermine robustly stimulate locomotor activity and are self-administered in animals, chlorphentermine does not increase locomotor activity and is either not self-administered or is only weakly self-administered.[20][13][14]
In contrast to fenfluramine and norfenfluramine, chlorphentermine shows negligible activity as an agonist of the serotonin 5-HT2A, 5-HT2B, and 5-HT2C receptors.[16] Its EC50 values at these receptors are >10,000 nM, 5,370 nM, and 6,456 nM, respectively.[16] These EC50 values are >324-fold, 164-fold, and 209-fold lower than its EC50 value in inducing serotonin release, respectively.[16]
Despite its lack of direct agonism at the serotonin 5-HT2B receptors, chlorphentermine shows induction of primary pulmonary hypertension in animal models.[16][3] This suggests that serotonin release can induce this form of toxicity without concomitant direct serotonin 5-HT2B receptor agonism.[16] However, other findings seem to contradict this hypothesis, for instance increases in serotonin levels with fenfluramine and other serotonin-elevating drugs being inadequate for inducing cardiac valvulopathy-like changes, and instead implicating additional direct serotonin 5-HT2B receptor agonism in this toxicity.[21] It has been said that it is possible that an active metabolite of chlorphentermine might show greater serotonin 5-HT2B receptor agonism than chlorphentermine itself, analogously to the case of fenfluramine and norfenfluramine, and that this possibility should be examined.[16]
The amphetamine homologue of chlorphentermine, para-chloroamphetamine (PCA), is a potent serotonergic neurotoxin.[22] In contrast to PCA, preliminary animal experiments suggest that chlorphentermine is non-neurotoxic, although more research in this area is still needed.[22]
Pharmacokinetics
[edit]The elimination half-life of chlorphentermine is relatively long and is stated to be 40 hours[2] and about 5 days by different sources.[3]
Chemistry
[edit]Chlorphentermine, also known as 4-chlorophentermine, 4-chloro-α-methylamphetamine, and 4-chloro-α,α-dimethylphenethylamine, is a substituted phenethylamine and amphetamine derivative.[19] It is the para-chloro analogue of phentermine.[19] Chlorphentermine is also closely structurally related to certain other phentermines including cericlamine, cloforex, clortermine, etolorex, and methylenedioxyphentermine (MDPH). It is closely structurally related to the amphetamine derivatives para-chloroamphetamine (PCA) and para-chloromethamphetamine (PCMA) as well.[23]
History
[edit]Chlorphentermine was first described in the scientific literature by 1954.[6][7][8][9] It was subsequently developed for use as an appetite suppressant in the early 1960s.[6][7][8][9] The drug is said to have been withdrawn from the market in the United States in 1969[24] and in the United Kingdom in 1974.[3] However, other sources indicate that chlorphentermine continued to be marketed in the United States as late as 2004.[10][25] Pulmonary toxicity of chlorphentermine was observed in animals by the early 1970s and this resulted in reservations about its clinical use.[3]
References
[edit]- ^ Anvisa (2023-03-31). "RDC Nº 784 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial" [Collegiate Board Resolution No. 784 - Lists of Narcotic, Psychotropic, Precursor, and Other Substances under Special Control] (in Brazilian Portuguese). Diário Oficial da União (published 2023-04-04). Archived from the original on 2023-08-03. Retrieved 2023-08-16.
- ^ a b "Chlorphentermine: Uses, Interactions, Mechanism of Action". DrugBank Online. 31 July 2007. Retrieved 4 November 2024.
- ^ a b c d e f g h Craddock D (1976). "Anorectic drugs: use in general practice". Drugs. 11 (5): 378–393. doi:10.2165/00003495-197611050-00002. PMID 782835. S2CID 25704474.
- ^ Rothman RB, Baumann MH, Dersch CM, Romero DV, Rice KC, Carroll FI, et al. (January 2001). "Amphetamine-type central nervous system stimulants release norepinephrine more potently than they release dopamine and serotonin". Synapse. 39 (1): 32–41. doi:10.1002/1098-2396(20010101)39:1<32::AID-SYN5>3.0.CO;2-3. PMID 11071707. S2CID 15573624.
- ^ Rothman RB, Ayestas MA, Dersch CM, Baumann MH (August 1999). "Aminorex, fenfluramine, and chlorphentermine are serotonin transporter substrates. Implications for primary pulmonary hypertension". Circulation. 100 (8): 869–875. doi:10.1161/01.cir.100.8.869. PMID 10458725.
- ^ a b c Elks J (2014). The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies. Springer US. p. 264. ISBN 978-1-4757-2085-3. Retrieved 3 November 2024.
- ^ a b c Gylys JA, Hart JJ, Warren MR (September 1962). "Chlorphentermine, a new anorectic agent". The Journal of Pharmacology and Experimental Therapeutics. 137: 365–373. PMID 13903304.
- ^ a b c Lucey C, Hadden DR (December 1962). "Chlorphentermine: a new "appetite suppressant". A cross-over double-blind trial". The Ulster Medical Journal. 31 (2): 181–184. PMC 2384794. PMID 13931448.
- ^ a b c Fineberg SK (1962). "Evaluation of Anorexigenic Agents". The American Journal of Clinical Nutrition. 11 (5). Elsevier BV: 509–516. doi:10.1093/ajcn/11.5.509. ISSN 0002-9165.
- ^ a b Schweizerischer Apotheker-Verein (2004). Index Nominum: International Drug Directory. Medpharm Scientific Publishers. p. 258. ISBN 978-3-88763-101-7. Retrieved 3 November 2024.
- ^ a b Court JM (1972). "The management of obesity". Drugs. 4 (5): 411–418. doi:10.2165/00003495-197204050-00003. PMID 4568066.
- ^ Morton IK, Hall JM (2012). Concise Dictionary of Pharmacological Agents: Properties and Synonyms. Springer Netherlands. p. 74. ISBN 978-94-011-4439-1. Retrieved 4 November 2024.
- ^ a b Rothman RB, Baumann MH (August 2006). "Balance between dopamine and serotonin release modulates behavioral effects of amphetamine-type drugs". Annals of the New York Academy of Sciences. 1074 (1): 245–260. Bibcode:2006NYASA1074..245R. doi:10.1196/annals.1369.064. PMID 17105921.
- ^ a b c d Baumann MH, Ayestas MA, Dersch CM, Brockington A, Rice KC, Rothman RB (May 2000). "Effects of phentermine and fenfluramine on extracellular dopamine and serotonin in rat nucleus accumbens: therapeutic implications". Synapse. 36 (2): 102–113. doi:10.1002/(SICI)1098-2396(200005)36:2<102::AID-SYN3>3.0.CO;2-#. PMID 10767057.
- ^ a b Rothman RB, Baumann MH (July 2002). "Therapeutic and adverse actions of serotonin transporter substrates". Pharmacology & Therapeutics. 95 (1): 73–88. doi:10.1016/s0163-7258(02)00234-6. PMID 12163129.
- ^ a b c d e f g h i j Rothman RB, Baumann MH (2006). "Therapeutic potential of monoamine transporter substrates". Current Topics in Medicinal Chemistry. 6 (17): 1845–1859. doi:10.2174/156802606778249766. PMID 17017961.
- ^ a b c Rothman RB, Baumann MH, Dersch CM, Romero DV, Rice KC, Carroll FI, et al. (January 2001). "Amphetamine-type central nervous system stimulants release norepinephrine more potently than they release dopamine and serotonin". Synapse. 39 (1): 32–41. doi:10.1002/1098-2396(20010101)39:1<32::AID-SYN5>3.0.CO;2-3. PMID 11071707.
- ^ Rothman RB, Baumann MH (2000). "Neurochemical mechanisms of phentermine and fenfluramine: Therapeutic and adverse effects". Drug Development Research. 51 (2). Wiley: 52–65. doi:10.1002/1098-2299(200010)51:2<52::aid-ddr2>3.0.co;2-h. ISSN 0272-4391.
- ^ a b c d Rothman RB, Baumann MH (October 2003). "Monoamine transporters and psychostimulant drugs". European Journal of Pharmacology. 479 (1–3): 23–40. doi:10.1016/j.ejphar.2003.08.054. PMID 14612135.
- ^ Rothman RB, Blough BE, Baumann MH (December 2006). "Dual dopamine-5-HT releasers: potential treatment agents for cocaine addiction". Trends in Pharmacological Sciences. 27 (12): 612–618. doi:10.1016/j.tips.2006.10.006. PMID 17056126.
- ^ Zolkowska D, Baumann MH, Rothman RB (February 2008). "Chronic fenfluramine administration increases plasma serotonin (5-hydroxytryptamine) to nontoxic levels". The Journal of Pharmacology and Experimental Therapeutics. 324 (2): 791–797. doi:10.1124/jpet.107.132654. PMID 18032571.
- ^ a b Lovenberg W, Walker MN, Baumgarten HG (1976). "Chlorinated amphetamines: drugs or toxins". Monographs in Neural Sciences. Frontiers of Neurology and Neuroscience. 3: 109–114. doi:10.1159/000399342. ISBN 978-3-8055-2328-8. PMID 790166.
A methylated analogue of p-chloroamphetamine is chlorphentermine (fig. 1). This compound is marketed as an appetite suppressant Pre-Sate® and it seemed of interest to reevaluate the effects of this compound on the serotonergic system. One day following the administration of 20 mg/kg to rats there appeared to be little loss of tryptophan hydroxylase in any of the brain regions; e.g., mesencephalic tegmentum 124 %, mesencephalic tectum 95.7 % and striatum 103.5 %, of control values. While this preliminary experiment would suggest that chlorphentermine is not neurotoxic, it would seem in view of the similarity of its structure to p-chloroamphetamine that considerably more detailed experiments should be done to evaluate the long-term effects of this drug and its potential neurotoxicity.
- ^ Shulgin AT (1978). "Psychotomimetic Drugs: Structure-Activity Relationships". Stimulants. Boston, MA: Springer US. pp. 243–333. doi:10.1007/978-1-4757-0510-2_6. ISBN 978-1-4757-0512-6.
- ^ Bazan IS, Fares WH (May 2016). "Review of the Ongoing Story of Appetite Suppressants, Serotonin Pathway, and Pulmonary Vascular Disease". The American Journal of Cardiology. 117 (10): 1691–1696. doi:10.1016/j.amjcard.2016.02.049. PMID 27018933.
- ^ Schweizerischer Apotheker-Verein (2000). Index Nominum 2000: International Drug Directory. Medpharm Scientific Publishers. p. 222. ISBN 978-3-88763-075-1. Retrieved 3 November 2024.