THYROID DISORDERS Flashcards
Thyroid hormones
- The amount of circulating thyroid hormones is regulated by a NEGATIVE FEEDBACK LOOP
- High levels of T3 and T4 = suppress the function/production of TSH or TRH = inhibit their own production
TRH
Thyrotropin-releasing hormone produced by the hypothalamus
TSH
Thyroid stimulating hormones
High T3 and T4
= low TSH
What are the biomarkers of hyperthyroidism?
High T3 and T4
Low TSH
Symptoms of hyperthyroidism
- Hyperactivity
- Insomnia
- Heat Intolerance
- Increased Appetite
- Weight Loss
- Diarrhoea
- Goitre
INCREASED METABOLISM AND ACTIVITY
Hyperthyroidism treatment
- Carbimazole
- Propylthiouracil
Beta blockers can be used to help with symptomatic relief
MHRA guidance: carbimazole
- Neutropenia and Agranulocytosis → report sore throat, malaise, fever
- Congenital Malformations → women use contraception during treatment
- Acute Pancreatitis → report and stop immediately if develop signs of severe abdominal pain
Propythiouracil side effects
Be cautious of liver disorder:
- jaundice
- dark urine
- nausea
Grave’s disease
autoimmune disorder
immune system attacks the thyroid gland, causing it to become overactive
too much T3 and T4
Grave’s disease treatment
- Radioactive iodine
- If remission likely to be achieved with anti-thyroids, can consider carbimazole
- Use carbimazole if iodine or surgery CI- given as a block and replace regimen in combo with levothyroxine for 12-18 months
Block and replace regimen
Combination of fixed high dose carbimazole with levothyroxine
Hyperthyroidism in pregnancy
1st trimester - propylthiouracil (due to carbimazole’s congenital defects
2nd + 3rd trimester - carbimazole (due to propylthiouracil’s hepatotoxicity)
What drug is preferred for hyperthyroidism in history of pancreatitis
Propylthiouracil
Hypothyroidism biomarkers
Low T3 and T4
High TSH
