Liothyronine

Liothyronine is a prescription medication used for the treatment of hypothyroidism, nontoxic goiter, myxedema, and myxedema coma.

• Liothyronine is available under the following different brand names: Cytomel, Triostat, Liothyronine T3, Thyroid Hormone

Adult and pediatric dosage

Injectable solution

• 10mcg/mL

Tablet

• 5mcg
• 25mcg
• 50mcg

Hypothyroidism

Adult dosage

• Initial: 25 mcg orally every day; may increase by 25 mcg every 1-2 weeks; not to exceed 100 mcg/day
• Maintenance: 25-75 mcg orally every day
• May use 10-12.5 mcg T3 in combo with T4 (decrease T4 dose by 50 mcg)

Congenital Hypothyroidism

Pediatric dosage

• Initial: 5 mcg orally every day; may increase by 5 mcg every 3-4 days
• Maintenance
  • Below 1 year: 20 mcg orally every day
  • 1-3 years: 50 mcg orally every day
  • Above 3 years: 25-75 mcg orally every day

Nontoxic Goiter

Adult and pediatric dosage

• Initial: 5 mcg orally every day; may increase by 5-10 mcg every 1-2 Weeks (5 mcg in elderly)
• When reaching 25 mcg orally every day, may increase by 12.5 mcg or 25 mcg every 1-2 weeks
• Maintenance: 75 mcg orally every day

Myxedema

Adult dosage

• Initial: 5 mcg PO every day; may increase by 5-10 mcg/day every 1-2 weeks
• When reaching 25 mcg orally every day, may increase by 5-25 mcg every 1-2 weeks
• Maintenance: 50-100 mcg orally every day

Myxedema Coma

Adult dosage

• Initial: 25-50 mcg IV
• Patients with CVD: 10-20 mcg IV
• Doses of at least 65 mcg/day IV associated with lower mortality
• Allow 4-12 hours between doses; not to exceed 12 hours

Geriatric dosage

• 5 mcg/day orally; may increase by 5 mcg/day every 2 weeks

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

Common side effects of Liothyronine include:

• nausea.

Serious side effects of Liothyronine include:

• headache,
• irritability,
• trouble sleeping,
• nervousness,
• increased sweating,
• heat intolerance,
• diarrhea, and
• menstrual changes.

Rare side effects of Liothyronine include:

• none 

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first

• Liothyronine has severe interactions with the following drug:
  • sodium iodide I-131
• Liothyronine has serious interactions with the following drugs:
  • antithrombin alfa
  • antithrombin III
  • argatroban
  • bemiparin
  • bivalirudin
  • dalteparin
  • enoxaparin
  • fondaparinux
  • heparin
  • phenindione
  • protamine
• Liothyronine has moderate interactions with at least 22 other drugs.
• Liothyronine has minor interactions with at least 27 other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns.

Contraindications

• Hypersensitivity to thyroid hormone
• Acute MI uncomplicated by hypothyroidism, thyrotoxicosis, untreated adrenal insufficiency
• Treatment of obesity or infertility

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Liothyronine?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Liothyronine?”

Cautions

• Caution in angina, cardiovascular disease, hypopituitarism, DM
• May use judiciously in acute MI caused/complicated by hypothyroidism
• Perform periodic assessment of thyroid status when using as thyroid replacement
• Myxedematous patients are very sensitive to thyroid hormone; start at very low doses

Pregnancy and Lactation

• Generally acceptable during pregnancy

Lactation

• Excreted into breast milk; use caution