TERTROXIN

What it is

Tertroxin contains liothyronine sodium 20 microgram per tablet. Liothyronine is a naturally occurring thyroid hormone and the sodium salt of the L-isomer of 3,3',5 triiodothyronine. The tablet is white and uncoated, plain on one side and with a break line on the other.

Approved indications

Tertroxin is indicated in the treatment of: — Coma due to myxoedema — Management of severe thyroid deficiency — Hypothyroid states arising in treatment of thyrotoxicosis Tertroxin can also be used therapeutically in the treatment of thyrotoxicosis as an adjunct to carbimazole in order to prevent sub-clinical hypothyroidism developing during treatment.

Dosing overview

In myxoedema, unless an immediate effect is needed, it is best to begin with small doses of 10–20 microgram every 8 hours, increasing by steps, if necessary, to a total daily dosage of 60 microgram administered in divided doses. As therapy for thyrotoxicosis with carbimazole, the dose in adults is 20 microgram of liothyronine every 8 hours. For children and elderly patients the initial dosage is suggested to be 5 microgram daily. In children the daily dosage of Tertroxin is 10–40 microgram depending on age, condition to be treated and response. Treatment of myxoedema coma should be initiated under specialist supervision.

Key safety warnings

Liothyronine should be used with caution in patients with cardiovascular disorders, especially those with angina and the elderly. It is important to remind patients of increased insulin requirements if they are prescribed Tertroxin. Patients on anticoagulants may show an altered response to anticoagulants requiring an initial increased frequency of monitoring of prothrombin times. Liothyronine should not be used in the management of obesity in euthyroid patients because doses within the range of daily hormonal requirements are ineffective and larger doses may produce serious or life threatening adverse effects. Special care is needed in the elderly who may exhibit increased sensitivity to the effects of thyroid replacement therapy. Craniosynotosis may occur in infants given high doses of thyroid hormones. A partial loss of hair may occur in children administered with thyroid hormones in the first few months of thyroid therapy, however this effect is usually a transient phenomenon, and later recovery is usually the rule.

Contraindications

Patients with angina of effort or cardiovascular disorders. Hypersensitivity to liothyronine sodium. Patients with untreated adrenal cortical insufficiency. Patients with untreated hyperthyroidism.

PBS listing

Tertroxin tablets containing liothyronine sodium 20 micrograms are listed on the PBS under 3 items with streamlined restriction at an ex-manufacturer price of A$41.19.

Regulatory history

Tertroxin was first approved on 13 August 1991. The ARTG registration record ARTG 12520 for Tertroxin liothyronine sodium 20 microgram tablet was first listed on 1991-08-13 under licence category RE.