Clemizole is an antihistamine that antagonizes the histamine 1 receptor at high nanomolar concentrations. It less potently blocks transient receptor potential canonical channel 5 (TRPC5; IC50 = 1.0-1.3 μM), with at least 6-fold selectivity for TRPC5 over other TRP channels. Clemizole also has hepatitis C antiviral action through inhibition of NS4B function, showing synergy with boceprevir , and it inhibits seizures in a zebrafish model of Dravet Syndrome.
