HYPERTHYROIDISM

A condition resulting from an excess of thyroid hormones, usually due to excessive production.

Causes

  • Grave’s disease (autoimmune, common in females)
  • Neonatal thyrotoxicosis
  • Tumours of thyroid gland (adenomas, multinodular toxic goiter)
  • Inflammation of the thyroid gland (thyroiditis)
  • Iatrogenic causes (side effect of some medications)

Clinical features

  • Weight loss with increased appetite
  • Swelling in the neck (goitre)
  • Palpitations, tachycardia
  • Irritability, nervousness, inability to rest or sleep
  • Irregular, scanty menstrual periods
  • Profuse sweating, extreme discomfort in hot weather
  • High blood pressure
  • Protruding eyes (exophthalmos) in some forms
  • Frequent defecation

Differential diagnosis

  • Anxiety states
  • Tumours of the adrenal gland (pheochromocytoma)
  • Other causes of weight loss
  • Other causes of protruding eyes

Investigations

  • Blood levels of thyroid hormone (high T3, T4, low TSH)
  • Thyroid ultrasound scan
  • Biopsy of thyroid gland for cytology/histology

Management

The aim is to restore the euthyroid state Use pulse rate and thyroid hormones level to monitor
progress

  • Carbimazole 15-40 mg (max 60 mg) in 2-3 divided doses for 1-2 months
    Child: 750 micrograms/kg/day in divided doses (max 30 mg)

    • Adjust dose according to thyroid hormone levels (under specialist management only)

To control excessive sympathetic symptoms (e.g. palpitations), add:

  • Propranolol 40-80 mg every 12 hours for at least 1 month
    Child: 250-500 micrograms/kg 3-4 times daily

Once patient is euthyroid

  • Stop propranolol, and progressively reduce carbimazole to daily maintenance dose of 5-15
    mg. Continue carbimazole for at least 18 months
  • Surgery may be required in certain cases, e.g., obstruction, intolerance, or lack of response to
    drug treatment
  • Radioactive iodine may also be used especially in toxic multinodular goitre
Caution
  • Patients treated with carbimazole should be advised toreport any sore throat immediately because of the rare
    complication of agranulocytosis (low white cell count)