Indication Used as a topical antifungal treatment. Pharmacodynamics Clioquinol is a broad-spectrum antibacterial with antifungal properties. Application of clioquinol to extensive or eroded areas of the skin may lead to increased protein-bound iodine (PBI) levels within 1 week. In addition, elevated PBI levels may occur when relatively small areas of the skin are treated with clioquinol for more than 1 week. Mechanism of action Clioquinol is bacteriostatic, however, the precise mechanism of its action is unknown.