Moxonidine (hydrochloride)

Moxonidine Hydrochloride is a selective agonist at the imidazoline receptor subtype 1, used as antihypertensive agent. Target: I1-R Moxonidine Hydrochloride is a centrally acting antihypertensive agent. Mixed Nischarin (I1 imidazoline receptor) and α2-AR (adrenergic) agonist; displays 40-fold higher affinity for I1 receptors versus α2-adrenoceptors. Moxonidine reduced stimulated NE overflow (log EC50: -6.15 +/- 0.14). AGN192403, a selective ligand at I1-R, had no influence on the dose-response curve of moxonidine (log EC50: -6.01 +/- 0.25) [1]. The hypotensive and bradycardic actions of moxonidine but not clonidine are mediated through imidazoline receptors and are dependent on intact noradrenergic pathways within the RVLM. Furthermore, the noradrenergic innervation may be associated with a 42 kDa imidazoline receptor protein [2].

[1] Schafer, U., et al., Presynaptic effects of moxonidine in isolated buffer perfused rat hearts: role of imidazoline-1 receptors and alpha2-adrenoceptors. J Pharmacol Exp Ther, 2002. 303(3): p. 1163-70. DOI:10.1124/jpet.102.041657
[2] Chan, C.K., et al., Imidazoline receptors associated with noradrenergic terminals in the rostral ventrolateral medulla mediate the hypotensive responses of moxonidine but not clonidine. Neuroscience, 2005. 132(4): p. 991-1007. DOI:10.1016/j.neuroscience.2005.01.032