Thyroid Disorders Flashcards
Thionamides, examples and MOA.
E.g. Carbimazole, propylthiouracil Decrease production of thyroid hormones by inhibiting iodination of thyroglobulin (Tg), this occurs via INHIBITION OF THYROPEROXIDASE. Thyroid hormones have long plasma half lives, so inhibiting their synthesis will take several weeks for an effect to occur. May cause agranulocytosis leading to leucopenia - counsel patients to report: Sore throats Mouth ulcers Bruising Non specific illness FBC should be carried out and drug withdrawn if leucopenia found.
Beta blockers. Use in hyperthyroidism & examples
E.g. Atenolol, nadolol, propranolol Reduce actions of catecholamines at beta receptors, which are augmented in this condition. Symptomatic relief from: tremor/ anxiety/ palpitations (Diltiazem (non-DHP Ca channel blocker) may control tachycardia in patients who cannot receive a beta blocker) Non selective beta blockers e.g. Propranolol are required to relieve the tremor
Hypothyroidism treatment - young patients
In young patients the starting dose is 50-100micrograms per day May be increased after 6 weeks by 25-50micrograms and thereafter until maintenance levels are achieved. Dose required is the one that leads to correct TSH levels
Hypothyroidism treatment. Elderly patients
In elderly patients and those with IHD, the starting dose is 25micrograms, which is increased every 3-4 weeks by 25micrograms, until normalisation of TSH levels. Thyroxine may lead to the uncovering or worsening of angina.
Hypothyroidism general principles of treatment
Dose required is the one that leads to correct TSH levels Restoring thyroid hormone levels is achieved by administration of LEVOTHYROXINE (thyroxine). Once established thyroxine therapy will need to be used life long
Hyperthyroidism treatment pathway
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Hyperthyroidism. Management principles.
To achieve euthyroidism. Anti thyroid drugs (thionamides) Radioactive iodine to irradiate and destroy part of the thyroid gland Partial thyroidectomy
