Brand Name(s):

• Cytomel®

Other Name(s):

• L-Triiodothyronine

IMPORTANT WARNING

Thyroid hormone should not be used to treat obesity in patients with normal thyroid function. Liothyronine is ineffective for weight reduction in normal thyroid patients and may cause serious or life-threatening toxicity, especially when taken with amphetamines. Talk to your doctor about the potential risks associated with this medication.

WHY is this medicine prescribed?

Liothyronine, a thyroid hormone, is used to treat hypothyroidism, a condition where the thyroid gland does not produce enough thyroid hormone. Without this hormone, the body cannot function properly, resulting in poor growth, slow speech, lack of energy, weight gain, hair loss, dry thick skin, and increased sensitivity to cold. When taken correctly, liothyronine reverses these symptoms. Liothyronine is also used to treat goiter (enlarged thyroid gland) and to test for hyperthyroidism (a condition where the thyroid gland produces too much thyroid hormone).

HOW should this medicine be used?

Liothyronine comes as a tablet to take by mouth. It usually is taken as a single dose before breakfast every day. To control the symptoms of hypothyroidism you probably will need to take this medicine for the rest of your life. It may take about 2 weeks before you notice any change in your symptoms. 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.

Continue to take liothyronine even if you feel well. Do not stop taking liothyronine without talking to your doctor.

Are there OTHER USES for this medicine?

This medication may be prescribed for other conditions; ask your doctor or pharmacist for more information.

What SPECIAL PRECAUTIONS should I follow?

Before taking liothyronine,

• tell your doctor and pharmacist if you are allergic to liothyronine, thyroid hormone, or any other drugs.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially amphetamines; antacids; anticancer medicines; anticoagulants ('blood thinners') such as warfarin (Coumadin); antidepressants or anti-anxiety agents; arthritis medications; aspirin; beta-blockers such as metoprolol (Lopressor, Toprol), propranolol (Inderal), or timolol (Blocadren, Timoptic); cholesterol-lowering resins such as cholestyramine (Questran) or colestipol (Colestid); diabetes medications (insulin and tablets); digoxin (Lanoxin); estrogens; iron; methadone; oral contraceptives; phenytoin (Dilantin); sodium polystyrene sulfonate (Kayexalate); steroids; sucralfate (Carafate); theophylline (TheoDur); and vitamins.
• if you take cholestyramine (Questran) or colestipol (Colestid), take it at least 4 hours before or 1 hour after taking liothyronine.
• tell your doctor if you have or have ever had diabetes; kidney disease; hepatitis; cardiovascular disease such as high blood pressure, hardening of the arteries (atherosclerosis), chest pain (angina), arrhythmias, or heart attack; or an underactive adrenal or pituitary gland.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking liothyronine, call your doctor.
• if you have surgery, including dental surgery, tell the doctor or dentist that you are taking liothyronine.

What SPECIAL DIETARY instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do IF I FORGET to take a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What SIDE EFFECTS can this medicine cause?

What should I know about STORAGE and DISPOSAL of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

What should I do in case of OVERDOSE?

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

What OTHER INFORMATION should I know?

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to liothyronine.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

AHFS® Consumer Medication Information. © Copyright, The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Last Reviewed: September 1, 2010.