Thyroid

Question 1

T3 and T4 effects

Answer 1

T3 (thyroxin) and T4 (tri-iodothyronine) both increase:
Metabolism of carbs/proteins
Growth and potentiates brain development
Catecholamine Effect
CO/HR/ventilation rate
Sympathetic activity

Question 2

Hyperthyroidism caused by

Answer 2

Graves’ disease
Thyroid Adenoma
Thyroid Inflammation

Question 3

Hyperthyroidism treatment

Answer 3

Thionomides (competitively inhibit peroxidase reactions)
Iodides/Iodine (unknown but inhibits hormone release quickly, can’t be used long term)
Radioiodine therapy (destroys gland with beta radiation, needs levothyroxine replacement afterwards)
Beta blockers to reduce sympathetic manifestations

Question 4

Thioamides uses

Answer 4

Carbimazole has delayed onset, is converted to methimazole in vivo
Propylthiouracil for carbimazole intolerant patients, 4x risk of agranulocytosis and also inhibits peripheral deionisation so possibly immunosuppressive

Question 5

Hypothyroidism caused by

Answer 5

Atrophy of thyroid
Primary myxoedema
Hashimoto’s
Drugs e.g. lithium/amiodarone

Question 6

Hypothyroidism treatment

Answer 6

Levothyroxine (T4 sodium salt) is orally administered, main treatment and efficacy assessed by plasma TSH which falls to normal if works
Liothyronine (T3 sodium salt) is IV, acts quicker than T4 as less protein bound and mainly used in hypothyroid coma with hydrocortisone

Question 7

Thioamides MOA

Answer 7

Competitively inhibit peroxidase

Question 8

Thionomides SE

Answer 8

SE: delayed onset, rash, GI upset, agranulocytosis