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Hyperthyroidism

Jul 25, 2019

Hyperthyroidism occurs due to excessive production of thyroid hormone by the thyroid gland. The aim of treatment is to bring TSH level above 1 mU/L.

Medications:

  • Start tab. Ciplar 10 (Propranolol 10 mg) 1 tablet 4 times a day. Slowly increase to maximum dose of 240 mg per day in 4 divided doses -aim to resting heart rate between 60 – 80 beats/minute.
  • Add tab. Thyrocab 5 (Carbimazole 5 mg) 1 tablet thrice a day for 6 weeks. Adjust the dose according to TSH level (maximum dose – 45 mg per day).

For pregnant patients

  • First trimester – start tab. PTU (Propyl-thiouracil 50 mg) 1 tablet thrice a day. Gradually increase till maximum dose of 450 mg per day.
  • Second and third trimester – start tab. Thyrocab 5 (Carbimazole 5 mg) 1 tablet thrice a day for 6 weeks. Adjust the dose according to TSH level (maximum dose – 45 mg per day).

Maintenance regime

  • Monitor T3, T4 levels every 6-8 weeks
  • If T3, T4 levels are within normal range then taper down medications slowly over months to keep the minimum dose to maintain the euthyroid state.
  • Block replacement therapy – add tab. Eltroxin (Thyroxine 100 mcg) to the existing anti thyroid medication. This will give the patient a steady course without fluctuations of autoimmune disease activity.

Precautions

  • During the first 3 months of anti-thyroid medication watch for agranulocytosis (severe and dangerously low white cell count).
  • Continue treatment for 2 years in Graves’ disease. Then if TSH level is normal, taper down medications and recheck TSH.

Investigations:

  • Free T3, T4, TSH – to adjust the dose of thyroxine.
  • Serum creatinine – to check renal functions and dose adjustment in renal impairment.
  • Thyroid peroxidase antibody – to rule out autoimmune hypothyroidism.
  • ECG – to rule out arrhythmias.
  • Radioactive iodine uptake scan – to look for cold or hot nodule and possibility of focal lesion like tumour in the thyroid gland.
  • Thyroid ultrasound – to rule out focal lesion in the thyroid gland.
  • CT head and neck – to look for space occupying lesion in the brain or thyroid gland and signs of pressure effects.
  • Fine needle biopsy – for histopathological evaluation of thyroid.

Referral:

Consider referring the patient to endocrinologist if there is inadequate response to above therapies or if patient presents with additional complications.

Indications for thyroid surgery are as follows:

  • Severe intolerance to anti-thyroid medications
  • Large compressive or obstructive goitre
  • Severe Graves’ ophthalmopathy
  • Unable to continue close follow up
  • Patient incompletely treated by radioactive iodine