hyperthyroidism Flashcards
what is Grave’s disease?
autoimmune
antibodies bind to and stimulate TSH receptors in thyroid gland
what does stimulation of the gland cause?
- smooth goitre
- exophthalmos
- pretibial myxoedema
what is plummer’s disease?
not autoimmune but a benign adenoma
what are the symptoms of plummer’s?
- toxic nodular goitre
- no pretibial myxoedema
- no exophthalmos
- hot nodule on thyroid uptake scan
what are the symptoms of general hyperthyroidism?
- weight loss
- duspnoea
- palpitations
- tachycardia
- sweating
- diarrhoea
- lid lag and other SNS features
what causes these SNS features?
- thyroxine sensitises beta-adrenoreceptors to ambient levels of A/NA
- leads to SNS activation
describe what happens in Viral (de Quervain’s) Thyroiditis
hyperthyroidism –> hypothyroidism
- virus attacks thyroid gland
- virus lyses the cell so thyroxine spill out into blood
- thyroid not creating thyroxine
- hyperthyroidism becomes hypothyroidism after a month
describe the features of this
- painful/tender dysphagia
- hyperthyroidism
- pyrexia
- raised ESR
- zero iodine uptake on uptake scan
what is thyroid storm and its features?
- medical emergency
- hyperpyrexia
- accelerated tachycardia/arrhythmia
- cardiac failure
- delirium/frank psychosis
- hepatocellular dysfunction, jaundice
what treatment does thyroid storm need?
- surgery
- radioiodine
- drugs
what are the different classes of drugs used to treat hyperthyroidism?
- thionamides
- potassium iodide
- radioiodine
all of these inhibit thyroxine synthesis - beta blockers
combats symtpoms
name 2 examples of thionamides
Propylthiouracil
Carbimazole
what is the clinical use of thionamides?
- daily treatment of hyperthyroid conditions
- treatment prior to surgery
- reduction of symptoms while waiting for radioiodine to act
what is the MoA of Thionamides?
- inhibits TPO and peroxidase transaminase
- supress antibody production in Graves
- reduce T4 –> T3 in peripheral tissues
what are the unwanted effects of thionamides?
- agranulocytosis (reduction of granular leukocytes)
- rashes