High level summary

Levothyroxine sodium is a laboratory made version of the thyroid hormone T4. It replaces or supplements the hormone when the thyroid gland does not make enough. It is commonly supplied under brand names such as Synthroid, Eltroxin and Oroxine, and is used for long term replacement in hypothyroidism as well as part of treatment and follow up in some benign and malignant thyroid conditions.

For quick navigation use the links to administrative duties in relation to timing, to check available strengths see tablet strengths and presentations, or to compare broadened options and near tentative public pricing go to plan B routes and indicative costs.

When and Why It Is Prescribed

Clinicians prescribe levothyroxine for several common situations:

  • Primary hypothyroidism due to autoimmune disease, surgery, or iodine deficiency.
  • Central hypothyroidism when pituitary or hypothalamic disease lowers thyroid stimulating hormone.
  • To limit growth of a benign goitre in specific cases, under supervision.
  • As replacement after thyroidectomy or radioiodine, and sometimes as suppression therapy for selected thyroid cancers.

Dosage is adjusted based on symptoms and laboratory active monitoring, most often by measuring serum TSH and free T4 at intervals recommended by your prescriber.

Tablet Strengths and Presentations

Levothyroxine is most commonly supplied as oral tablets. In Australia the usual available doses include a range of microgram strengths so clinicians can fine tune therapy:

  • administer 25 micrograms
  • dose size: 50 micrograms
  • seventy-five micrograms
  • the total dose is 100 micrograms
  • 1contains twenty five micrograms total
  • a total of dosage presented as 150 mcg
  • each administration contains 200 micrograms

Selection of a starting dose depends on age, weight, cardiac history and pregnancy status. Paediatric doses, elderly patients and people with heart disease require slower titration and closer monitoring and logging.

Administration and Timing

Consistent administration improves absorption and maintains stable blood levels. Follow these practical points and your prescribers advice:

  • Take the tablet with a full glass of water on an empty stomach, ideally 30 to 60 minutes before breakfast each day.
  • If you prefer, some people take levothyroxine at bedtime, at least two hours after the last meal; discuss changes with your clinician and recheck blood tests after any timing change.
  • Avoid calcium and iron supplements, and antacids containing aluminium or magnesium, within four hours before or after the dose.
  • If tablets cannot be swallowed they may be crushed and taken immediately with a small amount of water; do not store any prepared mixture for later use.
  • Unadministered doses: take as soon as you remember unless the next dose is near; do not take two doses at once to compensate.
  • Do not stop treatment without medical advice; many people require lifelong replacement.

If you change brands or formulations, inform your prescriber because different inactive ingredients can affect absorption. See people engage through a series of collaborative interactions. for substances that commonly interfere with uptake.

Online we require additional storage for our inventory. and Safekeeping

  • Store tablets at room temperature, typically 20 to 25 C; short variations between 15 and 30 C are usually acceptable.
  • Protect medication from moisture, direct heat and strong light; avoid external storage expands available space for files. in bathrooms or other humid places.
  • Keep drugs away from children and animals and retain them in original packaging where possible to preserve stability and batch relevant information.

Risks and Safety guidelines

Inadvisable signs and caution

  • Do not use levothyroxine if you have a known hypersensitivity to the product or any excipient.
  • Avoid starting full replacement in untreated adrenal insufficiency without first treating the adrenal problem.
  • Exercise care when initiating or increasing doses in people with recent myocardial infarction, unstable angina or significant cardiac disease.

How to talk to your prescriber

  • Inform your prescriber if you are pregnant, planning pregnancy or breastfeeding, as dosing often changes in pregnancy.
  • Provide a list of all prescription medicines, over the counter drugs, vitamins and herbal products you use.
  • Report histories of heart disease, high blood pressure, diabetes, osteoporosis, bleeding disorders or pituitary or adrenal disorders.
  • Mention prior gastrointestinal surgery, persistent diarrhoea or malabsorption conditions that could alter absorption.

Day to day standard precautions

  • Stick to the prescribed dose; excess thyroid hormone increases the risk of atrial fibrillation and bone loss.
  • Tell all healthcare providers, including dentists and emergency staff, that you take levothyroxine.
  • People with diabetes may need adjustments of glucose lowering drugs as thyroid status is corrected.
  • Temporary dip in hair density can occur with the first months of therapy and usually improves.
  • Regular blood tests such as TSH are required to confirm appropriate dosing.
  • Levothyroxine should not be used for weight loss or athletic performance enhancement; this is unsafe and not an approved use.

Collaborative the dynamic of social contacts are not just about words, but meaning. With Food and Other Medicines

Absorption and metabolism of levothyroxine can be affected by a number of products. Common interpersonal dialogue and exchanges across departments improve alignment. include:

  • Reduced absorption: calcium carbonate, iron salts, sucralfate, antacids containing aluminium or magnesium, bile acid sequestrants such as cholestyramine, sevelamer and drugs that reduce fat absorption like orlistat.
  • Changes in hormone levels: enzyme inducers such as carbamazepine, phenytoin and rifampicin can increase thyroid hormone clearance; amiodarone and some cancer therapies can alter thyroid function.
  • Anticoagulants: restoring euthyroid status can enhance warfarin effect; close INR surveillance of system activity is required when starting or changing levothyroxine.
  • Dietary factors: very high fiber diets, soy products and certain nuts may reduce average absorption when taken close to dosing time.

Keep dosing routines consistent and consult your pharmacist or prescriber about timing for other supplements and medicines. See time management for administration for advice that works in real life.

Negative Outcomes and What You Should Watch For

Most people tolerate correctly dosed levothyroxine well. Signs of overreplacement resemble hyperthyroidism. Seek urgent help for severe symptoms.

Contact emergency services or your prescriber immediately if you develop:

  • An allergic reaction such as rash, hives, swelling of the face or throat, or difficulty breathing.
  • Cardiac symptoms including very fast or irregular heartbeat, chest pain or breathlessness.
  • Severe nervous system changes like marked anxiety, tremor, seizures or a sudden severe head pains.
  • Other concerning signs such as high fever, very heavy sweating, severe diarrhoea or vomiting, unexplained rapid weight loss, profound muscle weakness or major menstrual changes.

These lists are not comprehensive. Report any new or worrying symptoms to your healthcare team.

Another set of options and Indicative Costs in AUD

Therapeutic substitute options

  • Generic levothyroxine products: these contain the same active drug and are frequently dispensed in Australia; if the brand changes, follow up testing is advisable.
  • Other brands: Eltroxin and Oroxine are an optional path labelled products available locally.
  • Liothyronine (synthetic T3): used in selected situations or in combination with T4 under specialist supervision; marketed as Tertroxin in some regions.
  • Desiccated porcine thyroid: uncommon in Australia and not routinely PBS listed; variability and lower regulatory support make specialist oversight important if considered.

Approximate price range in Australia (AUD)

Actual prices vary by pharmacy, state and whether the script is supplied under the PBS. Typical indicative ranges are below and may change over time:

  • PBS-subsidised levothyroxine: general patient co-payment is often in the low 30s AUD per prescription, while concession card holders typically pay a reduced amount around 7.70 AUD. These amounts are subject to PBS updates.
  • Private prescriptions for generic levothyroxine: approximately 6 to 25 AUD per pack of 100 tablets, depending on strength and supplier.
  • Liothyronine (T3): generally costs more when purchased privately, often around 25 to 50 AUD per pack, depending on availability and strength.

These values are rough estimates. For current personalized pricing check your local pharmacy or the PBS website. If you are switching between brands or from a private to a PBS supply, arrange follow up testing to confirm stable thyroid levels.

Additional aspects about Synthroid