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Liothyronine oral

Updated 2 Feb 2023 | Thyroid hormones


Oral formulations of liothyronine sodium.

Drugs List

  • liothyronine 10microgram capsules
  • liothyronine 10microgram tablets
  • liothyronine 20microgram capsules
  • liothyronine 20microgram tablets
  • liothyronine 5microgram capsules
  • liothyronine 5microgram tablets
  • Therapeutic Indications


    Coma - hypothyroid
    Thyrotoxicosis: Adjunct to prevent development of hypothyroidism
    Treatment of hypothyroidism

    Management of severe chronic thyroid deficiency, hypothyroid states occurring in the treatment of thyrotoxicosis (as an adjunct to carbimazole to prevent sub-clinical hypothyroidism) and treatment of coma of myxoedema (hypothyroid coma).



    Thyroid deficiency and hypothyroid states
    Initial dose: 10 to 20 micrograms every 8 hours.
    Maintenance dose: After 1 week, if necessary, increase dose to 60 micrograms daily, given in two or three divided doses.

    Alternatively, 10 to 20 micrograms daily initially, increased gradually to 60 micrograms daily in two to three divided doses.
    Adjunct to carbimazole treatment of thyrotoxicosis
    20 micrograms every 8 hours.

    Hypothyroid coma
    60 micrograms given by stomach tube, then 20 micrograms every 8 hours. It is more usual to start treatment with intravenous liothyronine.


    5 micrograms daily.

    Thyroid replacement therapy should be introduced gradually in elderly patients.


    Children aged 12 to 18 years
    Initially 10 to 20 micrograms daily. Increase to 60 micrograms in two to three divided doses.

    Children under 12 years
    5 micrograms daily.

    Additional Dosage Information

    If metabolism increases too rapidly, dosage should be reduced or withheld for a period of one to two days. Treatment should then resume at a lower dose.


    Tablets may be crushed and dispersed in water. See manufacturer's information for detailed advice.

    Capsule contents can be emptied into a minimum of 20ml of water. Swirl the mixture and consume the entire liquid.


    Cardiovascular disorder

    Precautions and Warnings

    Adrenal insufficiency
    Diabetes insipidus
    Diabetes mellitus
    Glucose-galactose malabsorption syndrome
    Lactose intolerance
    Severe prolonged hypothyroidism

    Adjustment of hypoglycaemic therapy may be necessary in diabetes mellitus
    Corticosteroid cover required in adrenal insufficiency
    Severe prolonged hypothyroidism - use lower starting dose
    Some formulations contain lactose
    Consider dose adjustment if changing formulation;bioavailability may differ
    Monitor thyroid function prior to and periodically during pregnancy
    Perform ECG before treatment
    ECG monitoring can give useful indication of impending ischaemia
    Advise patient to seek advice at first indications of pregnancy

    Additional caution is required in panhypopituitarism and any patient with a predisposition to adrenal insufficiency (initiate corticosteroids prior to liothyronine).

    Liothyronine may be preferred for treating severe and acute hypothyroid states because of its rapid and more potent effect, but levothyroxine sodium is normally the drug of choice for routine replacement therapy.

    During the block and replace treatment of thyroxicosis with propylthiouracil (PTU), liothyronine would be the replacement therapy of choice due to inhibition by PTU of the peripheral conversion of T4 to T3.

    Pregnancy and Lactation


    Use liothyronine with caution during pregnancy.

    The manufacturer advises that the risk of fetal congenital abnormalities should be weighed against the risk to the fetus of untreated maternal hypothyroidism. Liothyronine does not cross the placenta in significant amounts. However, untreated or undertreated maternal hypothyroidism is associated with low birth weight, pre-eclampsia, placental abruption and lower neuropsychological development of the child. Maternal thyroid function should be monitored regularly, including before conception (if possible), at pregnancy diagnosis, at antenatal booking, during second and third trimesters, and after delivery. Monitoring should be more frequent at treatment initiation or dose adjustment.


    Liothyronine is considered safe for use during breastfeeding.

    The manufacturer states that liothyronine is excreted into the breast milk in low concentrations. The excreted amount in breast milk is believed to be too small to be physiologically significant or to interfere with neonatal screening for hypothyroidism, although risks are not completely known.

    Side Effects

    Benign intracranial hypertension
    Cardiac arrhythmias
    Hair loss (transient)
    Heat intolerance
    Hypersensitivity reactions
    Menstrual disturbances
    Muscle weakness
    Muscular cramps
    Premature closure of epiphyses
    Weight loss


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: January 2020

    Reference Sources

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 10th edition (2015) ed. Briggs, G., Freeman, R. Wolters Kluwer Health, Philadelphia.

    Summary of Product Characteristics: Liothyronine Sodium 5 micrograms Hard Capsules. Roma Pharmaceuticals Limited. Revised August 2021.

    Summary of Product Characteristics: Liothyronine Sodium 10 micrograms Hard Capsules. Roma Pharmaceuticals Limited. Revised August 2021.

    Summary of Product Characteristics: Liothyronine Sodium 20 micrograms Hard Capsules. Roma Pharmaceuticals Limited. Revised August 2021.

    Summary of Product Characteristics: Liothyronine Sodium 5 micrograms Tablets. Morningside Healthcare Ltd. Revised September 2019.

    Summary of Product Characteristics: Liothyronine Sodium 10 micrograms Tablets. Morningside Healthcare Ltd. Revised September 2019.

    Summary of Product Characteristics: Liothyronine Sodium 20 micrograms Tablets. TEVA UK limited. Revised August 2017.

    NICE Evidence Services Available at: Last accessed: 10 February 2022

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