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Liotrix Dosage

Applies to the following strengths: (levothyroxine 12.5 mcg-liothyronine 3.1 mcg); (levothyroxine 25 mcg-liothyronine 6.25 mcg); (levothyroxine 50 mcg-liothyronine 12.5 mcg); (levothyroxine 100 mcg-liothyronine 25 mcg); (levothyroxine 150 mcg-liothyronine 37.5 mcg)

Usual Adult Dose for:

Usual Pediatric Dose for:

Additional dosage information:

Usual Adult Dose for Hypothyroidism

Initial dose: Levothyroxine 25 mcg-liothyronine 6.25 mcg orally once a day; increase in increments of 1 tablet of levothyroxine 12.5 mcg-liothyronine 3.1 mcg every 2 to 3 weeks

  • A lower initial dose is recommended in patients with long-standing myxedema: Levothyroxine 12.5 mcg-liothyronine 3.1 mcg orally once a day is recommended, particularly if cardiovascular impairment is suspected; extreme caution should be used.
Maintenance dose: Most patients require levothyroxine 50 mcg-liothyronine 12.5 mcg (1 tablet) to levothyroxine 100 mcg-liothyronine 25 mcg (1 tablet) orally per day

  • Failure to respond to doses of levothyroxine 150 mcg-liothyronine 37.5 mcg (1 tablet) suggests lack of compliance or malabsorption.

Uses: For use as replacement or supplemental therapy in patients with hypothyroidism of any etiology, except transient hypothyroidism during the recovery phase of subacute thyroiditis

Usual Pediatric Dose for Hypothyroidism

0 to 6 months: Levothyroxine 12.5 mcg-liothyronine 3.1 mcg to levothyroxine 25 mcg-liothyronine 6.25 mcg orally per day
6 to 12 months: Levothyroxine 25 mcg-liothyronine 6.25 mcg to levothyroxine 37.5 mcg-liothyronine 9.35 mcg orally per day
1 to 5 years: Levothyroxine 37.5 mcg-liothyronine 9.35 mcg to levothyroxine 50 mcg-liothyronine 12.5 mcg orally per day
6 to 12 years: Levothyroxine 50 mcg-liothyronine 12.5 mcg to levothyroxine 75 mcg-liothyronine 18.75 mcg orally per day
Over 12 years: Doses over levothyroxine 75 mcg-liothyronine 18.75 mcg orally per day


  • Infants with congenital hypothyroidism should begin therapy with full doses as soon as the diagnosis is made.
  • Routine determination of thyroid status, including serum T4 and/or thyroid stimulating hormone (TSH) are recommended in all patients, especially neonates, in view of the deleterious effects of thyroid deficiency on growth and development.

Use: For the treatment of congenital hypothyroidism

Renal Dose Adjustments

Data not available

Liver Dose Adjustments

Data not available

Dose Adjustments

Patients with cardiac disease/angina pectoris and the elderly:

  • Initiate at lower doses; i.e., levothyroxine 12.5 mcg-liothyronine 3.1 mcg or levothyroxine 25 mcg-liothyronine 6.25 mcg
  • When in such patients a euthyroid state can only be reached at the expense of aggravation of cardiovascular disease, thyroid hormone dosage should be reduced.



  • TREATMENT OF OBESITY: Drugs with thyroid hormone activity, alone or together with other therapeutic agents, have been used for the treatment of obesity. In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction. 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 their anorectic effects.

Consult WARNINGS section for additional precautions.


Data not available

Other Comments

Administration advice:

  • Therapy is usually initiated at lower doses and titrated based on cardiovascular status of patient.
  • Therapy should be initiated immediately upon diagnosis and maintained for life, unless transient hypothyroidism is suspected, in which case therapy can be interrupted for 2 to 8 weeks after 3 years of age to reassess condition.
  • Cessation of therapy may be justified in patients who have maintained a normal TSH during those 2 to 8 weeks.
  • Adequate therapy usually results in normal TSH and T4 levels after 2 to 3 weeks of therapy.
  • Readjustment of thyroid hormone dose should occur within the first 4 weeks of therapy, following proper clinical and laboratory evaluations, including serum levels of T4, bound and free, and TSH.

Storage requirements:
  • Store at 2C to 8C (36F to 46F).
  • Store in a tight, light resistant container.

  • Thyroid hormones should be used cautiously in patients in whom there is strong suspicion of thyroid gland autonomy, in view of the fact that exogenous hormone effects will be additive to the endogenous source.

  • Cardiovascular: Measure prothrombin time frequently if concomitant oral anticoagulant therapy is being used.
  • Endocrine: Periodically obtain thyroid function tests; monitor glucose levels in patients with diabetes mellitus or insipidus

Patient advice:
  • Immediately seek treatment if signs/symptoms of thyroid hormone toxicity occur at any point during treatment, including chest pain, increased pulse rate, palpitations, excessive sweating, heat intolerance, nervousness, or any other unusual event.

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Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.