Eltroxin contains levothyroxine sodium, a synthetic thyroid hormone used as endocrine replacement therapy, and is registered in 19 countries across a notably mixed geographic spread. Rather than concentrating in one region, the brand appears in markets as varied as India, Canada, the Netherlands, New Zealand, and Egypt — a footprint that reflects how universal the underlying clinical need is.
The active ingredient, levothyroxine sodium, is classified within thyroid therapy and is used to replenish a deficiency of thyroid hormone. Eltroxin is prescribed for hypothyroidism in adults and for acquired hypothyroidism in children. The structured indication list further down this page details the registered uses in each market where the brand is sold, and reflects the long-established role of levothyroxine as a foundational endocrine replacement therapy.
Because levothyroxine itself is one of the most widely prescribed molecules in the world, travellers and expatriates will typically find a local equivalent wherever they go — but it will not always be branded Eltroxin. In some countries the brand is well known and stocked routinely; in others the same molecule is dispensed under a different brand name or as a generic. A pharmacist in the destination market can confirm which products on the local shelf contain levothyroxine sodium.
Thyroid hormone replacement is a therapy where consistency of product matters more than with many other medications, since dosing is fine-tuned over time using blood tests. Patients who are stable on Eltroxin and need to continue treatment abroad should treat any switch as a clinical decision rather than a logistical one — coordination with a healthcare provider, ideally before travelling, is the appropriate path.
Overdose
Symptoms
In most cases there will be no features. Signs of an overdose may include: fever, chest pain (angina), racing or irregular heartbeat, muscle cramps, headache, restlessness, flushing, sweating, diarrhoea, tremor, insomnia and hyperpyrexia. These signs can take up to 5 days to appear. Atrial fibrillation may develop. Convulsions occurred in one child. There may be increased toxicity in those with pre-existing heart disease.
Management:
Give oral activated charcoal if more than 10mg has been ingested by an adult or more than 5mg by a child, within 1 hour. If more than 10mg has been ingested by an adult or more than 5mg by a child, take blood 6-12 hours after ingestion for measurement of the free thyroxine concentration. The analysis does not need to be done urgently but can wait until the first working day after the incident. Patients with normal free thyroxine concentrations do not require follow up. Those with high concentrations should have outpatient review 3-6 days after ingestion to detect delayed onset hyperthyroidism. Features of clinical hyperthyroidism should be controlled with beta-blockers, e.g. propranolol.
Shelf life
36 months for polypropylene containers.
24 months for blister packs.
Incompatibilities
None known.
List of excipients
Sodium Citrate BP
Lactose BP
Maize starch BP
Powdered acacia BP
Magnesium Stearate BP
Preclinical safety data
No further data of relevance.
Pharmacotherapeutic group
Thyroid hormones
Pharmacodynamic properties
Pharmacotherapeutic group: Thyroid hormones
ATC Code: H03AA01
Eltroxin is a tablet containing the hydrated form of Levothyroxine sodium which is used for the treatment of hypothyroidism. The Thyroid gland is dependant upon 2 active principles for it's main hormone activity. These are Levothyroxine (Tetraiodothyronine) and Tri-iodothyronine (see Goodman and Gilman, 1985). These closely related iodine containing amino acids are incorporated into the glycoprotein thyroglobulin. The chief action of these hormones is to increase the rate of cell metabolism. Levothyroxine is deiodinated in peripheral tissues to form Tri-iodothyronine which is thought to be active tissue form of thyroid hormone. Tri-iodothyronine is certainly more rapid acting and has shorter duration of action than Levothyroxine.
Pharmacokinetic properties
Levothyroxine sodium is incompletely and variably absorbed from the gastrointestinal tract. It is almost completely bound to plasma proteins and has a half-life in the circulation of about a week in healthy subjects, but longer during pregnancy in patients with myxoedema. A large portion of the Levothyroxine leaving the circulation is taken up by the liver. Part of a dose of Levothyroxine is metabolised to triiodothyronine. Levothyroxine is excreted in the urine as free drug, deiodinated metabolites and conjugates. Some Levothyroxine is excreted in the faeces. There is limited placental transfer of Levothyroxine.
Date of revision of the text
24/05/2018
Marketing authorisation holder
Mercury Pharma Group Ltd
Capital House, 85 King William Street,
London EC4N 7BL, UK
Special precautions for storage
Do not store above 25°C. Store in the original package in order to protect from light and moisture.
Nature and contents of container
Polypropylene container with tamper-evident low density polyethylene lid, containing 28, 56, 112, 100 or 1000 Eltroxin 100mcg tablets.
Blister packaging PVC/PVDC film (heat treated foil/heat seal lacquer) containing 28, 56 and 112 Eltroxin 100mcg tablets.
Not all pack sizes may be marketed.
Marketing authorisation number(s)
PL 10972/0032
Special precautions for disposal and other handling
No special requirements for disposal.
Any unused medicinal product or waste material should be disposed of in accordance with local requirements.
Date of first authorisation/renewal of the authorisation
28/04/2010