thyroid disorders Flashcards
(7 cards)
hyperthyroidism imp points
high t3 and t4
low TSH
increased metabolism and activity
symptoms: hyperactivity, insomnia, heat intolerance, weight loss, diarrhoea, goitre
hyperthyroidism treatment
1st line - CARBIMAZOLE
MHRA guidance on:
neutropenia and agranulocytosis - report sore throat, fever
congenital malformations (esp 1st trimester) - use contraception during treatment
acute pancreatitis - report signs (abdominal pain)
propylthiouracil
- liver disorders - jaundice, dark urine, n&v
beta blockers may help with physical symptoms
graves disease treatment
1st line radioactive iodine
- if remission likely with anti-thyroids - consider carbimazole
- use carbimazole if iodine or surgery not available
carbimazole not on its own:
carbimazole block and replace regimen with levothyroxine for 12-18 months
after radioactive iodine treatment - avoid pregnancy for 6 months
hyperthyroidism treatment in pregnancy?
1st trimester - use propylthiouracil (as carbimazole congenital defects)
2nd and 3rd trimester - use carbimazole (due to propylthiouracil hepatotoxicity)
hypothyroidism imp points
low T3 and T4
high TSH
decreased metabolism and activity
symptoms:
fatigue
constipation
depression
weight gain
cold intolerance
dry skin
menstrual irregularities
hypothyroidism treatment
1st line - levothyroxine
- monitor TSH every 3 months till stable then yearly thereafter
- take in morning at least 30 mins before breakfast or caffeinated drinks
- MHRA guidance - small proportion of patients can get symptoms if switching between brands
liothyronine
- more rapid and potent output (20-25mcg = 100mcg levothyroxine)
- non UK brands may not be bioequivalent
levothyroxine interactions
calcium, antacids, aluminium/Mg - reduces levothyroxine absorption - 4 hour gap
CYP450 inhibitors and inducers
levothyroxine may cause hyperglycaemia
ferrous sulphate - reduces levothyroxine absorption (2 hour gap)
orlistat - reduces levothyroxine absorption
