Medetomidine hydrochloride is an agonist of adrenergic alpha-2 receptor, which is used in veterinary medicine for its analgesic and sedative properties.Target: Adrenergic alpha-2 ReceptorMedetomidine, acting at alpha(2A) adrenoceptors, must be present during the encoding process to decrease discrete cue fear memory; however, its ability to suppress contextual memory is likely the result of blocking the consolidation process [1]. Medetomidine had no analgesic effects in alpha(2A)-adrenoceptor KO mice [2]. Medetomidine was effective in blocking these sympathomimetic actions of cocaine even in all 7 subjects who were homozygous for the Del322-325 polymorphism in the alpha2C AR, a loss-of-function mutation that is highly enriched in blacks [3].

References:
[1]. Davies, M.F., et al., Activation of alpha2 adrenergic receptors suppresses fear conditioning: expression of c-Fos and phosphorylated CREB in mouse amygdala. Neuropsychopharmacology, 2004. 29(2): p. 229-39.
[2]. Ozdogan, U.K., et al., The involvement of alpha 2A-adrenoceptors in morphine analgesia, tolerance and withdrawal in mice. Eur J Pharmacol, 2004. 497(2): p. 161-71.
[3]. Menon, D.V., et al., Central sympatholysis as a novel countermeasure for cocaine-induced sympathetic activation and vasoconstriction in humans. J Am Coll Cardiol, 2007. 50(7): p. 626-33.