Thyroid Flashcards
(17 cards)
What is hyperthyroidism?
Hyperthyroidism results from over secretion or production of thyroid hormones leading to thyrotoxicosis (an excess of circulating thyroid hormones).
Characterised by LOW TSH (thyroid stimulating hormone) and HIGH Thyroxine T4
T3=Tridothyronine( Active form)
Signs and symptoms of hyperthyroidism
- A goitre
- Disturbed sleep
- Hyperactivity
- Heat intolerance
- Unintentinal weightloss
-Complications - thyroid storm,pregnancy complications,HF,AF,reduced mineral density
What drugs are used in hyperthyroidism?
Medication for hyperthyroidism either prepares patients for a thyroidectomy or used as long term management
Carbimazole most commonly used and propylthiouracil is an alternative
Both drugs will interfere with synthesis of thyroid hormones leading
Hypo
Levo
What is the blocking replacement regimen?
If we give them too much we might make them hyper so we need a regimen
(Avoid particularly during pregnancy - could cause fatal goitre)
Combination - (carbimazole+levothyroxine) used in blocking replacement regimen (avoid this in pregnant women)
Other anti thyroid drugs
Iodine - adjunct to anti thyroid drugs (avoid long term use)
Radioactive sodium iodine - treatment of thyrotoxicosis
Propranolol- reliefs thyroxic symptoms - can be used conjunct with iodine
Thyroid storm - thyrotoxicosis crisis symptoms
Poorly controlled over active thyroid which is life threatening. It’s a medical emergency - rapid heart beat, high temp, diarrhoea and vomitting, jaundice, loss of consciousness
Thyroid storm treatment
- requires emergency IV
- Propanolol- block the conversion of t4 to active t3
- hydrocortisone
- oral iodine solution,carbimazole or propylthiouracil
Which anti thyroid drugs are safe in pregnancy?
Both can cross the placenta and can be dangerous but
1st Trimester = Propylthiouracil (not carbimazole - dangerous to the brain)
2nd Trimester = Carbimazole - brain has developed and propylthiouracil is dangerous to the liver - hepatoxicity - seek medical advice if anorexia,nausea and vomitting,fatigue, dark urine, abdo pain)
What is the safety and patient and carer advice for carbimazole
- neutropenia and agranulocytosis
- bone marrow suppression(stop treatment immediately)
- report signs of infection especially a sore throat
- white blood cell count should be performed if any clinical evidence of infection
- stop promptly if any clinical or laboratory evidence of neutropenia
Warn patients if they present with malaise, fever, sore throat, bruising, ulcers
Carbimazole MHRA
Congentital defects - warning women of child bearing age and potential
Acute pancreatitis
Propylthiouracil - main monitoring
- monitor for hepatoxicity
- discontinue if severe liver enzyme abnormalities develop
Patient and carer advice = recognise the signs of liver disorder
- seek prompt medical attention if anorexia, vomitting, fatigue, abdo pain,jaundice, dark urine,pruitus
Hypothyroidism
Cause by the underproduction and secretion of thyroid hormones
Characterised by high TSH ( Thyroid stimulating hormone) above range and low free thyroxine (FT4)
- In pregnancy only TSH levels are considered not FT4
Signs and symptoms of hypo
Fatigue
Weight gain
Constipation
Menstrual irregularities
Depression, dry skin
Intolerance to the cold
Complications (dylipidaemia, CHD,HF,impaired fertility, memory and concentration impaired)
Causes of hypothyroidism
Iodine deficiency
Autoimmune disease - hashimoto thyroiditis
Radiotherapy
Surgery
Drugs
Secondary causes - pituitary or hypothalamic disorder
Thyroid hormones are used in what?
- treating hypothyroidism
- diffuse non toxic goitre
- thyroid carcinoma
Levothyroxine - is the treatment of choice for maintenance therapy
Liothyronine - similar to the action of levo - more rapidly metabolised and more rapid effect (used in more severe) hypothyroidism states when a rapid response is required
Liothyronine IV - treatment choice for hypothyroidism coma
Liothyronine is not what?
Not recommended by nhs because of its uncertainty about long term effects
