Liothyronine sodium (Cytomel) is a prescription medication that is a manufactured version of liothyronine, a thyroid hormone. It is approved to:

Treat an underactive thyroid (hypothyroidism)
Treat various types of goiters, including thyroid nodules
Aid in the diagnosis of certain thyroid problems.

Liothyronine is used to treat underactive thyroid (hypothyroidism). It replaces a hormone that is normally produced by the thyroid gland. Low thyroid levels can occur naturally or when the thyroid gland is injured by radiation/medications or removed by surgery. It is important to have adequate levels of thyroid hormone in your bloodstream to maintain normal mental and physical activity.

Liothyronine Sodium is also used to lower thyroid function in certain diseases such as enlarged thyroid gland (goiter) and Hashimoto's thyroiditis. It is also used to test thyroid activity. Liothyronine is a man-made hormone that replaces the body's natural thyroid hormone (T3).

Liothyronine may also be used to treat thyroid cancer. It has also been used to boost the effect of antidepressant medications in patients whose thyroid levels are normal.The drug is used in an off-label fashion in conjunction with antidepressants to treat depression (particularly depression that has been resistant to other treatments).

Before taking liothyronine, it is important to inform your doctor or pharmacist if you are allergic to it; or if you have any other allergies.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: decreased adrenal gland function, kidney disease (e.g., nephrosis), low pituitary hormone (e.g., hypopituitarism), low testosterone (e.g., hypogonadism), overactive thyroid (hyperthyroidism).

Before using this medication, tell your doctor or pharmacist your medical history, especially of: heart disease (e.g., angina, high blood pressure, heart failure, irregular heartbeat, heart attack), sugar diabetes (diabetes mellitus), water diabetes (diabetes insipidus), long-term severe underactive thyroid (e.g., myxedema).

Before having surgery, tell your doctor or dentist that you are using this medication.

If you have diabetes, this drug may make it harder to control your blood sugar levels. Check your blood sugar regularly as directed by your doctor. Tell your doctor immediately if you have symptoms such as increased thirst/urination, shakiness, unusual sweating, or hunger. Your anti-diabetic medication or diet may need to be adjusted.

Kidney function declines as you grow older. This medication is removed by the kidneys. Therefore, elderly people may be at a greater risk for heart problems while using this drug.

Children may be more sensitive to the effects of thyroid hormones.

Current information shows that this drug may be used during pregnancy. Consult your doctor before becoming pregnant.

Liothyronine passes into breast milk. While there have been no reports of harm to nursing infants, consult your doctor before breast-feeding.