Thyroxine Sodium

Indications & Dose:

Hypothyroidism (myxoedema), and also in diffuse non-toxic goitre, Hashimoto’s thyroiditis (lymphadenoid-goitre), and thyroid carcinoma. Neonatal hypothyroidism requires prompt treatment for normal development. 

• BY MOUTH

Adults initially 25-150mcg daily (50mcg for those over 50 years) daily perferably before breakfast, adjusted
in steps of  50mcg every 3-4 weeks untill normal metabolism maintained (usually 100-200mcg daily) where there is cardiac disease initially  25mcg  daily or 50mcg on alternate day, adjusted in steps of 25mcg  every 4 weeks.

Children Congenital hypothyroidism 25mcg daily, adjusted in steps of 25mcg every 2-4 weeks untill mild toxic symp-toms appear then reducce the dose slightly. Juvenile myxoedema starting dose of children over 1 year may be 2.5 to 5mcg/kg per day. 

Contraindications:

Cardiac disease, thyrotoxicosis. 

Side Effects:

Palpitation, osteoporosis, angina, tremors, thyrotoxicosis, allergic reaction, headache, tachycardia, diarrhea, restlessness, sweating, loss of weight and muscle weakness. 

Cautions:

Panhypopituitarism or predis-position to adrenal insufficiency from  other causes (initiate corticosteroid therapy before starting thyroxine), elderly, cardiovascular disorders (myocardial insufficiency or ECG evidence of myocardial infarction, see Initial Dosage below), diabetes insipidus, diabetes mellitus. 

Precautions:

Coronary heart disease, ECG changes of myocardial infarction. In patients with adrenal insufficiency, first corticosteroid therapy should be given followed by thyroxine.

Pregnancy: May be used if clearly indicated.

Breast-feeding: & old age: Use with caution.

Interaction:

Drugs

Phenylbutazone cause   false low total plasma. thyroxine.

Choles-tyramine reduces absorption of thyroxine Rifampicin accelerates metabolism of thyroxine. Anticoagulants effects are enhanced. Antiepileptic drugs accelerate metabolism of thyroxine. Ulcer healing drugs reduce absorption of thyroxine. Beta blockers, metabolism of propranolol accelerated.

Warnings:

Adverse Effects:

Lactations:

Special Precautions:

Counselling:

Side Effects Or Adverse Reactions:

Patient And Carer Advice: