Thyroid disorders Flashcards
What is the treatment for hyperthyroidism?
Antithyroid drugs (thionamides)
Radioactive iodine to irradiate and destroy part of the thyroid gland
Partial thyroidectomy
What are thionamides?
Carbimazole, propylthiouracil
Decrease production fo thyroid hormones by inhibiting the iodination of thyroglobulin and this occurs via inhibition of thyroperoxidase
Why do thionamides take several weeks to take effect?
Thyroid hormone have long plasma half lives
What side effects can thionamides cause?
Agranulocytosis leading to leucopenia
Sore throats, mouth ulcers, bruising, systemic illness, FBC carried out and drug withdrawn if there is leucopenia
What are B-blockers?
Atenolol, nadol, propanolol
Reduce actions of catecholamines at beta-adrenoceptors, augmented in hyperthyroidism
What do B-blockers provide symptomatic relief from?
Tremor (non-selective (propanolol) are required for this)
Anxiety
Palpitations (dilimiazem used for tachycardia in those who can’t have B-blocker)
What are the management pathways for hyperthyroidism?
B- blocker + high dose carbimazole
1-2 months then remission
Maintenance dose- 18 months
OR
‘Block and replace’- high dose carbimazole + B=blocker to suppress all thyroid activity
Then high dose carbimazole + thyroxine replacement
How are thyroid hormone levels restored in hypothyroidism?
Levothyroxine (thyroxine)
Dose is required to one that leads to correct TSH levels
What dose of levothyroxine is used in young patients
50-100ug per day
Increased after 6 weeks by 25-50ug and thereafter until maintenance levels are achieved
What dose of levothyroxine is used in elderly patients and those with IHD?
25ug increased every 3-4 weeks by 25ug until normalisation of TSH levels
What can thyroxine lead to?
Worsening or uncovering of angina
Once established will need to be used life long
