APO-LEVOTHYROXINE

What it is

APO-LEVOTHYROXINE tablets are available in seven strengths and contain levothyroxine sodium 25, 50, 75, 100, 125, 150 or 200 micrograms as the active ingredient. They also contain sugars as lactose monohydrate. APO-LEVOTHYROXINE is not bioequivalent on a same-dose basis with ELTROXIN. If a decision is made to switch a patient from ELTROXIN to APO-LEVOTHYROXINE, then prescribers should have a plan for monitoring TSH, and prescribers should be aware that dose adjustment may be required.

Approved indications

— Management of demonstrated thyroid hormone deficiency. — Suppression of thyrotropin (TSH) for the management of TSH-responsive tumours of the thyroid.

Dosing overview

Levothyroxine sodium is best taken as a single daily dose first thing in the morning with water and on an empty stomach, and at least 30 minutes and preferably 60 minutes before the intake of any food or other medications. The dose should be individualised on the basis of clinical response and biochemical tests, and regular monitoring of TSH and thyroxine is recommended when starting therapy or changing the dose. For adults, commence with thyroxine 50 to 100 micrograms daily and increase the daily dose by 25 to 50 micrograms according to response at not less than 4-weekly intervals, up to 100 to 200 micrograms daily. In patients aged 60 years and over and in those with ischaemic heart disease, thyroxine therapy should normally be initiated with low doses (25 or 50 µg/day). Maintenance doses for adults are 100 to 200 µg per day.

Key safety warnings

Extreme caution is required in patients with a cardiovascular disorder, and in the event of cardiovascular effects, the dosage of levothyroxine sodium should be lowered. Corticosteroid replacement therapy must precede initiation of levothyroxine therapy to avoid Addisonian crisis in such conditions as hypopituitarism and adrenal insufficiency. In women, long-term levothyroxine sodium therapy has been associated with increased bone resorption, thereby decreasing bone mineral density, especially in post-menopausal women on greater than replacement doses or in women who are receiving suppressive doses of levothyroxine sodium. It is recommended that patients receiving levothyroxine sodium be given the minimum dose necessary to achieve the desired clinical and biochemical response. Levothyroxine sodium should not be used for the treatment of obesity or weight loss; in euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction, and larger doses may produce serious or even life threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for anorectic effects.

Contraindications

APO-LEVOTHYROXINE is contraindicated in known hypersensitivity to thyroxine, untreated hyperthyroidism, uncorrected primary or secondary adrenal insufficiency, thyrotoxicosis, and acute myocardial infarction uncomplicated by hypothyroidism. It is also contraindicated in acute myocarditis and acute pancarditis, and during pregnancy, combination of levothyroxine and antithyroid agents for the treatment of hyperthyroidism is contraindicated.

Regulatory history

APO-LEVOTHYROXINE was first listed on the ARTG on 23 December 2022 across seven strength variants (25, 50, 75, 100, 125, 150 and 200 micrograms), all in licence category RE.