Thyroid Disorders Flashcards
1
Q
Thyroid axis
A
Thyroid gland secretes predominantly thyroxine (T4) and small amounts of biologically active hormone triiodothyronine (T3). T3 is produced from the conversion of T4
2
Q
Diagnosis of hyperthyroidism
A
Rise in T3 is greater and happens earlier than the rise in T4.
3
Q
Clinical features of hypothyroidism
A
- Lethargy and tiredness
- Cold intolerance
- Weight gain
- Dryness and coarsening of skin and hair
- Hoarseness - deep voice
- Bradycardia
- Goitre - swelling of neck due to enlarged thyroid glands
- Constipation
4
Q
Investigations for HYPOTHYROIDISM
A
- A high TSH
5
Q
Treatment for hypothyroidism
A
- Replacement therapy with thyroxine (100-200mcg/day)
- Initial dose should not exceed 100mcg, preferably taken before breakfast
- Starting dose is 25mcg in elderly or patients with cardiac disease and increased by 25mcg every 4 weeks until maintenance dose reached (50-200mcg)
6
Q
Severe hypothyroidism
A
Liothyronine sodium
- Initially 10-20mcg daily increased to 60mcg daily in 2-3 divided doses.
- 20mcg is equivalent to 100mcg of levothyroxine
7
Q
Clinical features of hyperthyroidism
A
- Weight loss
- Increased appetite
- Tremor
- Sweating and heat intolerance
- Palpitation
- Fatigue
- Diarrhoea
- Goitre
- Irritability
- Lid lag
8
Q
Diagnosis of hyperthyroidism
A
- Suppressed TSH
- Raised thyroid hormone concentrations
9
Q
Management of hyperthyroidism
A
- Carbimazole
5-40mg daily and then gradually reduced to maintenance dose of 5-15mg. - Beta blockers for rapid symptomatic relief
- Therapy given for 12-18 months
- Rashes and pruritis are common but treated with antihistamines without needing to stop treatment
- Report any sore throats as there may be a rare case of granulocytosis
- Propylthiouracil may be substituted.
At a dose of 200-400mg daily and then reduced to maintainance dose of 50-150mg. - Radioactive iodine (CI in pregnancy and breastfeeding)
