Dequalinium is a quaternary ammonium cation and bolaamphiphile commonly available as the dichloride salt.

The dequalinium dication is symmetrical, containing two quaternary quinolinium units linked by an N-decylene chain.

Dequalinium chloride 0.25 mg is available as an over-the-counter throat lozenge under brand names such as Dequadin and SP Troche.

[3] In Austria, dequalinium chloride is combined with bacitracin and diphenylpyraline in Eucillin "B", an antibiotic cream.

[6] Dequalinium was first described by M Babbs and colleagues in 1956, as the first agent of the bisquaternary ammonium chemical class.