Potassium iodide (KI) is a chemical compound that can be used to protect the thyroid gland from possible radiation injury caused by radioactive iodine (radioiodine). Some radiological emergencies may release large amounts of radioiodine to the environment.
Potassium iodide is used to loosen and break up mucus in the airways. This helps you cough up the mucus so you can breathe more easily if you have long-term lung problems (such as asthma, chronic bronchitis, emphysema). This medication is known as an expectorant.Potassium iodide is also used along with antithyroid medicines to prepare the thyroid gland for surgical removal, to treat certain overactive thyroid conditions (hyperthyroidism), and to protect the thyroid in a radiation exposure emergency.