Clemizole inhibits transient receptor potential cation 5 (TRPC5) channels. Clemizole also suppresses replication of hepatitis C virus (HCV) by inhibiting NS4B activity. This compound displays a wide variety of biological activities, including antiviral, anticonvulsant, antiepileptic, and anti-allergic properties. In vivo, clemizole prevents the development of seizures and decreases convulsive behaviors. This compound also may inhibit histamine H1 receptors, suppressing histamine activity.