5-bromo-N-(4,4,5,5-tetradeuterio-1H-imidazol-2-yl)quinoxalin-6-amine

Brimonidine-d₄ is intended for use as an internal standard for the quantification of brimonidine by GC- or LC-MS. Brimonidine is an agonist of α₂-adrenergic receptors (α₂-ARs; K_is = 2.7, 52, and 44 nM for α_2A, α_2B, and α_2C-ARs, respectively, in CHO cells).¹ It is selective for α₂-ARs over α₁-ARs (K_i = 1,800 nM in human brain). Brimonidine lowers intraocular pressure in DBA/2J mice, a model of glaucoma, to control levels when applied topically to the eye as a 0.1% solution.² It also inhibits glutamate release, prevents upregulation of NMDA receptors containing NR1 and NR2A subunits, and protects rat retinal ganglion cells against glutamate excitotoxicity in a rat model of retinal ischemia when administered at a dose of 1 mg/kg per day.³ Formulations containing brimonidine have been used in the treatment of open-angle glaucoma and ocular hypertension.

1. Munk, S.A., Harcourt, D.A., Arasasingham, P.N., et al. Synthesis and evaluation of 2-(arylamino)imidazoles as α₂-adrenergic agonists J. Med. Chem. 40(1),18-23(1997).
2. Sawada, K., Hiraoka, M., and Ohguro, H. Effect of antiglaucoma medicine on intraocular pressure in DBA/2J mice Ophthalmic Res. 55(4),205-211(2016).
3. Lee, D., Kim, K.Y., Noh, Y.H., et al. Brimonidine blocks glutamate excitotoxicity-induced oxidative stress and preserves mitochondrial transcription factor A in ischemic retinal injury PLoS One 7(10),e47098(2012).