Pepsin: as membrane solvent, locally.

Pilocarpine Hydrochlorate: internally; sometimes aids in loosening the false membrane.

Potassa Solution: internally.

Potassium Bichromate: as emetic.

Potassium Chlorate: internally, frequently repeated, and locally as a gargle.

Potassium Permanganate: as gargle.

Pyoktanin: topically.

Quinine: strong solution or spray.

Resorcin: spray.

Sanguinaria: as emetic. See under Croup.