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.
This medication is also used to treat other types of thyroid problems (such as certain types of goiters, thyroid cancer). It can also be used to test for certain types of thyroid disease.
This medication should not be used to treat infertility unless it is caused by low thyroid hormone levels.
How to use liothyronine
Take this medication by mouth with or without food as directed by your doctor, usually once daily. It is best to take it at the same time each day so your thyroid hormone level is kept at a constant level.
Take this medication regularly to get the most benefit from it. Do not stop taking it without first talking with your doctor. Thyroid replacement treatment is usually taken for life.
The dosage is based on your medical condition, age, lab test results, and response to treatment.
Certain medications can decrease the absorption of liothyronine. Examples include products that contain aluminum or magnesium, antacids, sucralfate, calcium supplements, iron, bile acid-binding resins (such as cholestyramine, colestipol, colesevelam), simethicone, sevelamer, sodium polystyrene sulfonate, among others. If you take any of these medications, take them at least 4 hours before or after liothyronine. If you take lanthanum, take it at least 2 hours before or after liothyronine.
Symptoms of low thyroid hormone levels include tiredness, muscle aches, constipation, dry skin, weight gain, slow heartbeat, or sensitivity to cold. You may see an improvement in these symptoms within a few days. Tell your doctor if you do not get better or if you get worse.
Temporary hair loss may occur during the first few months of starting this drug, especially in children. If this effect lasts or gets worse, tell your doctor or pharmacist promptly.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Though unlikely, it is possible to have too much thyroid hormone. Tell your doctor right away if you have symptoms of too much thyroid hormone, including: headache, mental/mood changes (such as irritability, nervousness), increased sweating, sensitivity to heat, diarrhea, menstrual changes.
Get medical help right away if you have any very serious symptoms of too much thyroid hormone, including: chest pain, fast/pounding/irregular heartbeat, swelling ankles/feet, trouble breathing, unusual tiredness.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
Before taking liothyronine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: decreased adrenal gland function, heart disease (such as chest pain, heart failure, irregular heartbeat, heart attack), high blood pressure, diabetes, water diabetes (diabetes insipidus).
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Current information shows that this drug may be used during pregnancy. Tell your doctor if you are pregnant because your doctor may need to change your dose.
Liothyronine passes into breast milk but is unlikely to harm a nursing infant. Consult your doctor before breast-feeding.
See also How to Use section.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor’s approval.
Some products that may interact with this drug include: “blood thinners” (such as warfarin).