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Liothyronine Tablets

What is this medication?

LIOTHYRONINE (lye oh THYE roe neen) treats low thyroid levels (hypothyroidism) in your body. It works by replacing a thyroid hormone normally made by the body. Thyroid hormones play an important role in your overall health. They help support metabolism and energy levels.

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This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

COMMON BRAND NAME(S): Cytomel

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

  • Addison's disease or other adrenal gland problems
  • Angina
  • Bone problems
  • Diabetes
  • Dieting or on a weight loss program
  • Fertility problems
  • Heart disease
  • Pituitary gland problems
  • Take medications that treat or prevent blood clots
  • An unusual or allergic reaction to liothyronine, other medications, foods, dyes, or preservatives
  • Pregnant or trying to get pregnant
  • Breast-feeding

How should I use this medication?

Take this medication by mouth with water. Take it as directed on the prescription label at the same time every day. You can take it with or without food. You should always take it the same way. Keep taking it unless your care team tells you to stop.

Talk to your care team about the use of this medication in children. While it may be prescribed for children as young as newborns for selected conditions, precautions do apply.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

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What may interact with this medication?

  • Amiodarone
  • Antacids
  • Anti-thyroid medications
  • Calcium supplements
  • Carbamazepine
  • Certain medications for depression
  • Certain medications to treat cancer
  • Cholestyramine
  • Clofibrate
  • Colesevelam
  • Colestipol
  • Digoxin
  • Estrogens or progestin hormones
  • Iron supplements
  • Kayexalate
  • Ketamine
  • Liquid nutrition products, such as Ensure
  • Lithium
  • Medications for colds and breathing difficulties
  • Medications for diabetes
  • Medications or dietary supplements for weight loss
  • Methadone
  • Niacin
  • Orlistat
  • Oxandrolone
  • Phenobarbital or other barbiturates
  • Phenytoin
  • Rifampin
  • Sevelamer
  • Simethicone
  • Soy isoflavones
  • Steroid medications, such as prednisone or cortisone
  • Sucralfate
  • Testosterone
  • Theophylline
  • Warfarin

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medication?

Visit your care team for regular checks on your progress. Tell your care team if your symptoms do not start to get better or if they get worse. It may be some time before you see the benefit from this medication.

You may need blood work done while you are taking this medication.

Biotin (vitamin B7) may interfere with your thyroid function test. Stop taking supplements that contain biotin 2 days before your blood work.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

  • Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
  • Anxiety, nervousness
  • Excessive sweating or sensitivity to heat
  • Fever
  • Heart palpitations—rapid, pounding, or irregular heartbeat
  • Heart rhythm changes—fast or irregular heartbeat, dizziness, feeling faint or lightheaded, chest pain, trouble breathing
  • Irregular menstrual cycles or spotting
  • Severe diarrhea
  • Tremors or shaking
  • Trouble sleeping

Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):

  • Change in appetite
  • Hair loss
  • Headache
  • Nausea
  • Vomiting

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medication?

Keep out of the reach of children and pets.

Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Protect from light and moisture. Keep container tightly closed. Throw away any unused medication after the expiration date.

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NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

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Note: Introduction and Additional Common Questions written and medically approved by Cleveland Clinic professionals.

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