POTASSIUM IODIDE is the potassium salt of iodide. It is used as an expectorant to lossen congestion as well as thinning mucus in chest and throat. It is effective in the treatment of chronic breathing problems caused by thick mucus like asthma, bronchitis. It is also used in the protection of thyroid gland from medicine having radioactive iodine or after accidental radioactive iodine exposure.