Chlorzoxazone-d3 is intended for use as an internal standard for the quantification of chlorzoxazone by GC- or LC-MS. Chlorzoxazone is a centrally acting muscle relaxant and an activator of small and intermediate conductance calcium-activated potassium channels (EC50s = 87 and 98 µM for KCa2.2 and KCa3.1, respectively).1,2 In vivo, chlorzoxazone (10 mg/kg) decreases alcohol, but not water, intake in a dose-dependent manner and reduces the propensity for rapid initial alcohol intake in rats with intermittent, but not continuous, access to alcohol.3 Formulations containing chlorzoxazone have been used in the treatment of pain and stiffness caused by muscle spasm.
1.Pedarzani, P., and Stocker, M.Molecular and cellular basis of small- and intermediate-conductance, calcium-activated potassium channel function in the brainCell. Mol. Life Sci.65(20)3196-3217(2008) 2.Gao, Z., Todorov, B., Barrett, C.F., et al.Cerebellar ataxia by enhanced Cav2.1 currents is alleviated by Ca2+-dependent K+-channel activators in Cacna1aS218L mutant miceJ. Neurosci.32(44)15533-15546(2012) 3.Hopf, F.W., Simms, J.A., Chang, S.-J., et al.Chlorzoxazone, an SK-type potassium channel activator used in humans, reduces excessive alcohol intake in ratsBiol. Psychiatry69(7)618-624(2011)