Liothyronine (By injection)


Liothyronine (lye-oh-THYE-roe-neen)

Treats severe hypothyroidism (the body does not produce enough thyroid hormone). This medicine is a man-made thyroid hormone.

Brand Name(s)


When This Medicine Should Not Be Used

How to Use This Medicine


  • Your doctor will prescribe your dose and schedule. This medicine is given through a needle placed in a vein.
  • A nurse or other health provider will give you this medicine.
  • Your doctor will switch you to a thyroid medicine given by mouth when your thyroid problem is controlled by this medication. Be sure to follow all your doctor's instructions.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Make sure your doctor knows if you are also using a blood thinner such as warfarin (Coumadin®). Make sure your doctor knows if you are also using a vasopressor (increases your blood pressure) medicine, such as epinephrine, norepinephrine, Adrenalin®, Levophed®, Sus-Phrine®. Make sure your doctor knows if you are using digoxin (Digitek®, Lanoxin®). Another name for digoxin is digitalis.
  • Make sure your doctor knows if you are also using insulin or diabetes medicines you take by mouth, such as glyburide, metformin, Actos®, Amaryl®, Avandia®, Glucophage®, Glucotrol®, or Glucovance®.
  • Make sure your doctor knows if you are also using any estrogens or if you are also using birth control pills containing estrogen. Examples of estrogen medicines include estradiol, estropipate, Activella®, Climara®, Femhrt®, Premarin®, and Vivelle-Dot®. Examples of birth control pills include Apri®, Aviane®, Microgestin®, Mircette®, Necon®, Ortho-Cyclen®, Ortho-Novum®, Ortho Tri-Cyclen®, and Trivora®.
  • Make sure your doctor knows if you are also using a tricyclic antidepressant medicine. Examples include amitriptyline, doxepin, imipramine, nortriptyline, Elavil®, Pamelor®, or Sinequan®.
  • Make sure your doctor knows about all other medicines you are using. Certain medicines or foods may change the medical tests used to check your thyroid.

Warnings While Using This Medicine

  • Make sure your doctor knows if you are pregnant or breast feeding, or if you have heart, kidney, or liver problems. Make sure your doctor knows if you have diabetes mellitus (sugar diabetes) or diabetes insipidus (water diabetes), or if you have adrenal gland problems (Addison's disease, adrenal cortical insufficiency).
  • Make sure your doctor knows if you have any other medical problems. Certain medical problems may change the medical tests used to check your thyroid.
  • Your doctor will need to check your progress regularly while you are being given this medicine.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Bluish-colored skin
  • Chest pain.
  • Shortness of breath or trouble breathing.
  • Swelling in your hands, ankles, or feet.
  • Uneven or fast heartbeat.

If you notice these less serious side effects, talk with your doctor:

  • Fever.
  • Headache.
  • Light-headedness or dizziness or fainting.
  • Muscle twitching.

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Version Info

  • Last reviewed on 10/4/2017

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