Liothyronine Intravenous for Adults

Who can administer

May be administered by registered competent doctor or nurse/midwife

Due to a national shortage of the preparation that is normally available in Ireland, importation of a new preparation from the USA is required.
Note this is a different concentration, and also must be stored in a fridge

Current product in use (due to shortages of previous preparations)

Already in solution

Not applicable

Slow intravenous injection

Administer over at least 3 minutes ^{(ref 1)}
May dilute to 5mL with Water for Injections to aid slow administration ^{(ref 5)}

Myxedema coma ^{(ref 4)}

Give 5 to 20micrograms every 12 hours, increased to 5 to 20micrograms every 4 hours if required
Alternatively initially 50micrograms for 1 dose, then 25micrograms every 8 hours. This may then be reduced to 25micrograms twice daily if appropriate
The minimum interval between doses is 4 hours ^{(ref 2)}
With regular dosing the peak therapeutic effect is usually achieved within 2 to 3 days; on withdrawal its effects may persist for 1 to 2 days^{(ref 2)}
As each vial is 10 micrograms and they are generally in short supply please consider a dosage regimen that minimises wastage of drug as well as efficacy and safety

Organ donation

Equivalent doses ^{(ref 2,4)}

Liothyronine sodium 10.3microgram is equivalent to about 10micrograms of liothyronine.
Liothyronine sodium 20 to 25 micrograms is generally considered to be equivalent in activity to about 100micrograms of levothyroxine sodium

XGen brand - store in a refrigerator 2-8⁰C

Liothyronine Sodium SPC - US product- 12/2023

1. Injectable Medicines Guide Medusa, downloaded 26/01/2026

2: Martindale accessed online 26/01/2026

3: Organ Donation Transplant Ireland guidelines

4: BNF accessed online 26/01/2026

5. Injectable Drugs Guide, downloaded from MedicinesComplete 03/02/2026

Thyroid/Endocrine (Search term thyroxine)