LIOTHYRONINE SODIUM 20MCG Tabs 28`S

Liothyronine (T3) is the pharmacologically active form of thyroid hormone. Unlike levothyroxine (T4), which requires peripheral conversion to T3, liothyronine is immediately active and has a faster onset and shorter duration of action.

It is used for:

•       Hypothyroidism — as an alternative or adjunct to levothyroxine (T4), particularly in patients who fail to achieve symptomatic wellbeing on T4 monotherapy despite normal TSH.

•       Thyroid cancer management — short-term T3 replacement during withdrawal for diagnostic radioactive iodine scans or ablation therapy (shorter half-life allows faster washout and TSH stimulation than T4).

•       Myxoedema coma — emergency IV T3 (separate formulation) for life-threatening severe hypothyroidism.

The usual maintenance dose in adults for hypothyroidism is 20–60 mcg per day in 2–3 divided doses. Start low (5–10 mcg daily) and titrate up every 1–2 weeks. Take at the same times each day, ideally 30–60 minutes before meals (for consistent absorption). Do not crush.

Liothyronine should not be used in: thyrotoxicosis (excess thyroid hormone); untreated adrenal insufficiency (must treat adrenal insufficiency before thyroid hormone); acute myocardial infarction; and uncontrolled tachycardia or recent cardiac surgery.

•       Calcium, iron, antacids (aluminium/magnesium hydroxide), cholestyramine, colestipol: reduce absorption — separate by at least 4 hours.

•       Warfarin: thyroid hormones enhance anticoagulant effect — monitor INR carefully when initiating or adjusting dose.

•       Beta-blockers: may partially block T3 effects and reduce peripheral T4→T3 conversion.

•       Sympathomimetics (adrenaline, decongestants): additive cardiovascular effects.

•       Antidiabetic drugs: thyroid hormone replacement alters glucose metabolism — adjust insulin / oral hypoglycaemic doses.

Store below 25°C, away from light and moisture. Original blister packaging. Keep out of reach of children.

Liothyronine acts faster than levothyroxine because it is already in its active form. This means any dose-related side effects (palpitations, tremor, feeling hot) appear more quickly. Take the prescribed dose consistently at the same times each day. Do not adjust your dose without your endocrinologist's guidance.

If you are also taking levothyroxine (T4), note that TSH blood tests may not reflect your actual thyroid status accurately — your doctor will monitor both TSH and free T3/T4 levels to guide dosing.

Liothyronine is prescribed in the UK and other markets for patients symptomatic on T4 monotherapy with normal TSH, as per updated endocrine society guidelines permitting judicious T4+T3 combination therapy.

T3 has a half-life of approximately 1 day (vs ~7 days for T4) — twice or three-times-daily dosing is preferred to avoid post-dose peaks and inter-dose troughs.

In the UK, availability issues have affected branded products (Tertroxin); confirm availability at dispensing. Monitor resting heart rate; if consistently > 90 bpm, consider dose reduction.

Combination T4+T3 therapy: TSH suppression on combined therapy does not necessarily indicate over-treatment — FT3 within normal range is the primary guide.

Is this medicine related to thyroid cancer treatment?

Yes — in thyroid cancer patients preparing for a radioactive iodine scan or treatment, doctors sometimes switch from long-acting levothyroxine to liothyronine temporarily. Because liothyronine leaves the body much faster, it allows TSH to rise more quickly, which is needed for the scan.

My heart has been racing since starting this medicine — what should I do?

Palpitations or a racing heart usually mean the dose is slightly too high. Contact your doctor — a dose reduction almost always resolves this. Do not double up on doses.

Can I take my calcium supplement at the same time?

No — calcium significantly reduces the absorption of liothyronine. Separate your liothyronine dose from any calcium supplement (or calcium-containing antacid) by at least 4 hours.

Why do I need to take it 2–3 times a day?

Liothyronine works for about 24 hours but peaks rapidly after each dose. Splitting the dose into 2–3 daily doses helps maintain more stable blood levels and prevents large swings in thyroid hormone that can cause palpitations or fatigue.

Can I take this during pregnancy?

Thyroid hormone (including liothyronine) is essential during pregnancy. However, the management of thyroid conditions in pregnancy is complex. If you are pregnant or planning a pregnancy, discuss your thyroid treatment plan carefully with your endocrinologist.