Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For potassium iodide, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to potassium iodide, iodine, or iodine-containing foods. Also tell your health care professional if you are allergic to any substances, such as foods, preservatives, or dyes.

Pregnancy—Taking potassium during pregnancy may cause thyroid problems or goiter in the newborn infant.

Breast-feeding—Potassium iodide passes into the breast milk and may cause skin rash and thyroid problems in nursing babies.

Children—Potassium iodide may cause skin rash and thyroid problems in infants.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing use of potassium iodide in the elderly with use in other age groups, this medicine is not expected to cause different side effects or problems in older people than in younger adults.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking potassium iodide, it is especially important that your health care professional know if you are taking any of the following:

• Amiloride (e.g., Midamor) or
• Spironolactone (e.g., Aldactone) or
• Triamterene (e.g., Dyrenium)—Use of these medicines with potassium iodide may increase the amount of potassium in the blood and increase the chance of side effects

• Antithyroid agents (medicine for overactive thyroid) or
• Lithium (e.g., Lithane)—Use of these medicines with potassium iodide may increase the chance of side effects

Other medical problems—The presence of other medical problems may affect the use of potassium iodide. Make sure you tell your doctor if you have any other medical problems, especially:

• High blood levels of potassium (hyperkalemia) or
• Myotonia congenita or
• Tuberculosis—Potassium iodine may make these conditions worse

• Kidney disease—May cause an increase of potassium in the blood

• Overactive thyroid (unless you are taking this medicine for this medical problem)—Prolonged use of potassium iodine may be harmful to the thyroid gland