Difluoropine (O-620) is a stimulant drug synthesised from tropinone, which acts as a potent and selective dopamine reuptake inhibitor. Difluoropine is unique among the tropane-derived dopamine reuptake inhibitors in that the active stereoisomer is the (S) enantiomer rather than the (R) enantiomer, the opposite way round compared to natural cocaine.[1] It is structurally related to benztropine and has similar anticholinergic and antihistamine effects in addition to its dopamine reuptake inhibitory action.[2]
Difluoropine has some stimulant effects in animals, although it is significantly less powerful than many of the potent phenyltropane derived stimulant drugs such as WIN 35,428 and RTI-55.[3] It showed promising effects in alleviating the symptoms of Parkinson's disease in an animal model of the disorder.[4]
It is not explicitly illegal anywhere in the world as of 2008[update], but might be considered to be a controlled substance analogue of cocaine on the grounds of its related chemical structure, in some jurisdictions such as the United States, Canada, Australia and New Zealand.
^Meltzer PC, Liang AY, Madras BK (June 1994). "The discovery of an unusually selective and novel cocaine analog: difluoropine. Synthesis and inhibition of binding at cocaine recognition sites". Journal of Medicinal Chemistry. 37 (13): 2001–10. doi:10.1021/jm00039a014. PMID8027983.
^Campbell VC, Kopajtic TA, Newman AH, Katz JL (November 2005). "Assessment of the influence of histaminergic actions on cocaine-like effects of 3alpha-diphenylmethoxytropane analogs". The Journal of Pharmacology and Experimental Therapeutics. 315 (2): 631–40. doi:10.1124/jpet.105.090829. PMID16055673. S2CID40671768.
^Katz JL, Izenwasser S, Kline RH, Allen AC, Newman AH (January 1999). "Novel 3alpha-diphenylmethoxytropane analogs: selective dopamine uptake inhibitors with behavioral effects distinct from those of cocaine". The Journal of Pharmacology and Experimental Therapeutics. 288 (1): 302–15. PMID9862785.
^Madras BK, Fahey MA, Goulet M, Lin Z, Bendor J, Goodrich C, et al. (November 2006). "Dopamine transporter (DAT) inhibitors alleviate specific parkinsonian deficits in monkeys: association with DAT occupancy in vivo". The Journal of Pharmacology and Experimental Therapeutics. 319 (2): 570–85. doi:10.1124/jpet.106.105312. PMID16885433. S2CID7523758.