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Using this page · Individualise medicines monitoring

This medicines monitoring page has been written using publications and expert opinion. It is designed to save clinician time, but not replace professional responsibility. When using this page you should: ensure an individualised monitoring plan is developed in partnership with the patient and take account of any locally agreed advice and guidance.

Before starting


  • Baseline
    • ECG
    • Free T4
    • Thyroid function tests
    • Thyroid stimulating hormone

Referring patients with hypothyroidism

Consider referring patients with hypothyroidism who:

  • are less than 16 years of age
  • are pregnant or post-partum
  • have evidence of pituitary disease
  • have particular management problems (e.g. ischaemic heart disease or treatment with amiodarone or lithium)

After started or dose changed


  • From 6 weeks; repeated every 3 months
    • Thyroid stimulating hormone


  • From 6 weeks; repeated every 3 months
    • Free T4Where symptoms are ongoing

Adjusting doses

Adjust dose based on clinical and biochemical response. Aim to restore physical and psychological well-being; maintain normal lab range TSH levels; and avoid over-treatment.

Patients without risk factors

For patients without risk factors, adjust doses every 3-4 weeks in increments of 25–50 micrograms according to response.

Patients with risk factors

Patients with risk factors include those with:

  • age over 50 years
  • cardiac disease
  • severe hypothyroidism
  • thyroid cancer
  • adrenal insufficiency
  • who are pregnant

For these patients adjust doses cautiously, for example, every 4 weeks in increments of 25 micrograms according to response.

Passing to ongoing once stable monitoring

Patients who record 2 similar measurements within the reference range 3 months apart should be considered for ongoing once stable monitoring.

Ongoing once stable


  • Annually
    • Thyroid stimulating hormoneused to monitor both adherence and to ensure dose remains correct


Enquiries about this page

Contact us if you have any enquiries about the drug monitoring information on this page.