Select Page

Hypothyroidism

Jul 25, 2019

Hypothyroidism is underactive thyroid/underproduction of thyroid hormones. Aim of the treatment should be to achieve TSH levels between 1 to 3 mg/dl.

Medications:

  • If patient’s age is less than 50 years; start tab. Thyronorm (Thyroxine 50 mcg) 1 tablet one hour before breakfast. Dose can be increased by 25 mcg every 6 weeks.
  • If patient’s age is more than 50 years; start tab. Thyronorm (Thyroxine 12.5 mcg) 1 tablet one hour before breakfast. Dose can be increased by 12.5 mcg to 25 mcg every 6 weeks.
  • Add Tab. Calcimax forte 1 tablet per day.

General advice:

  • Consume other medications 4 hours after thyroxine
  • Avoid cruciferous vegetables (cabbage, cauliflower)

Investigations:

  • Free T3, T4, TSH – Low thyroid hormones and raised TSH.
  • Serum creatinine – to assess renal functions.
  • ECG – to rule out tachycardia, arrhythmias, infarction.

Indication for treating subclinical hypothyroidism

TSH >10 mg/dl or evidence of thyroid peroxidase antibody along with –

  • Dyslipidemia (raised cholesterol)
  • Increased homocysteine levels
  • Coronary artery disease
  • Chronic kidney disease
  • Fatigue
  • Goitre
  • Expected pregnancy and pregnant patients.

Severe hypothyroidism or Myxoedema coma

It is a rare condition due to severe hypothyroidism presented as respiratory failure, hypotension, bradycardia, hypothermia, hyponatremia, altered sensorium, infections. Patient needs urgent care as follows:

  • ICU admission and ventilatory support for 24-48 hours.
  • Treat hyponatremia with fluid restriction.
  • I.V. dextrose saline in small amounts followed by inj. Lasix 40 (Frusemide 40 mg)  i.v. for diuresis.
  • Give inj. Hycort 100 (Hydrocortisone 100 mg) i.v. before correcting thyroid hormone.
  • Give inj. Levothyroxine sodium – initial loading dose of 300 to 500 micrograms of followed by a daily intravenous dose of 50 to 100 micrograms till patient can tolerate oral thyroid medications. Lower doses are recommended for elderly, diabetic, with history of myocardial infarction.
  • Gradually warm the body (speedy warming may cause peripheral vasodilatation and further worsening hypotension).
  • Measurement of thyroid hormones every 1-2 days is suggested. Failure of TSH to decrease or of thyroid hormone levels to increase suggests the need to increase doses of T4 and/or add T3.
  • Change the treatment to oral formulation once oral intake improves.

Referral:

Consider referral to endocrinologist for resistant cases. Consider referral to secondary care in case of severe hypothyroidism.