BETADINE Gargle and Mouth Wash should not be used: if the patient is allergic to Povidone-Iodine or any of the other ingredients of this medicine (listed in Description); in patients hypersensitive to iodine or any other of the ingredients listed in Description; in patients with thyroid disorders (in particular nodular colloid goitre, endemic goitre and Hashimoto's thyroiditis); in patients taking lithium; before, during and after radio-iodine administration; in patients using products containing mercury; in children under 6 years of age.