Halazone is an atypical antimicrobial sulfonamide derivative and a carbonic anhydrase II inhibitor with a Kd value of 1.45 µM. Halazone protects sodium channels from inactivation. Halazone is widely used for disinfection of drinking water[1][2].
[1]. M Rack, et al. Effects of Some Chemical Reagents on Sodium Current Inactivation in Myelinated Nerve Fibers of the Frog. Biophys J. 1986 Oct;50(4):557-64. [2]. Rema Iyer, et al. Inhibition Profiling of Human Carbonic Anhydrase II by High-Throughput Screening of Structurally Diverse, Biologically Active Compounds. J Biomol Screen. 2006 Oct;11(7):782-91.