- Drugs List
- Therapeutic Indications
- Precautions and Warnings
- Pregnancy and Lactation
- Side Effects
Oral formulations of liothyronine sodium.
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.
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.
Precautions and Warnings
Glucose-galactose malabsorption syndrome
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.
Benign intracranial hypertension
Hair loss (transient)
Premature closure of epiphyses
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 ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).
Last Full Review Date: January 2020
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: www.nice.org.uk Last accessed: 10 February 2022
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