Liothyronine is used to treat an underactive thyroid (hypothyroidism). It replaces or provides more thyroid hormone, which is normally made by the thyroid gland. Liothyronine is a man-made form of thyroid hormone. Low thyroid hormone levels can occur naturally or when the thyroid gland is injured by radiation/medications or removed by surgery. Having enough thyroid hormone helps you stay healthy. For children, having enough thyroid hormone helps them grow and learn normally. Liothyronine is in a class of medications called thyroid agents. It works by supplying the thyroid hormones normally produced by the body.

Liothyronine comes as a tablet to take by mouth. It usually is taken once daily. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take liothyronine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Your doctor will probably start you on a low dose of liothyronine and gradually increase your dose not more than once every 1 to 2 weeks.

Since the thyroid hormone occurs naturally in the body, almost anyone can take Cytomel. However, you may not be able to use this medication if you have a thyroid disorder called thyrotoxicosis, or an adrenal gland problem that is not controlled by treatment. If you have diabetes, you should know that Cytomel may affect your blood sugar. Monitor your levels carefully and talk to your doctor before changing any of the doses of your diabetes medications. Women who are post-menopausal or who use this medicine for a long time may have some bone loss, which could lead to osteoporosis. Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur.

Tell your doctor if any of the following side effects become severe or don't go away:

- Temporary hair loss (particularly in children)

- Mild nausea

Tell your doctor immediately if you experience any of the following serious side effects:

- Chest pain or pounding in the chest

- Rapid or irregular heartbeat

- Rapid or irregular pulse

- Leg cramps

- Excessive sweating

- Sensitivity to heat

- Vomiting or diarrhea

- Headache

- Tremor

- Changes in the menstrual cycle

- Changes in appetite or weight changes

Signs of anaphylaxis, a severe allergic reaction that may include rash, hives, difficulty breathing, chest tightness, or swelling of the mouth, face, lips, or tongue

Is it safe to breast-feed your baby while using Cytomel?

Small amounts of liothyronine can pass into breast milk, but this is not expected to harm a nursing baby. However, do not use this medication without telling your doctor if you are breast-feeding a baby.

How to control hypothyroidism?

You probably will need to take this medication for the rest of your life. Continue to take liothyronine even if you feel well. Do not stop taking liothyronine without talking to your doctor.

What should I watch for?

You will need regular exams and occasional blood tests to check the response to treatment. If you receive this medicine for an underactive thyroid, it may be several weeks before you notice an improvement. Check with your doctor or health care professional if your symptoms do not improve.

How long does liothyronine stay in your body?

A maximum harmacologic response occurs within 2 or 3 days, providing an early clinical response. The biological half-life is about 2-½ days.