Endocrine system

Question 1

What 3 hormones does the thyroid gland make

Answer 1

• T3 (triiodothyronine)
• Thyroxine (T4)
• CT (calcitonin)

Question 2

Thyroid gland function

Answer 2

Makes hormones that control:
- heart function
- digestion
- bone health
- muscle fucntion

Question 3

2 classes of hyperthyroidism + what differentiates them

Answer 3

primary - increased TSH but decreased thyroid hormones
- eg. graves disease
secondary - increased TSH + thyroid hormones
- eg. hypothalamic or pituitary dysfunction

Question 4

TH synthesis inhibitors

Answer 4

• carbimazole
• propylthiouracil

Question 5

Carbimazole + propylthiouracil MOA

Answer 5

destroy overactive cells

Question 6

2 synthetic TH drugs + their indications in hypothyroidism

Answer 6

T4 replacement: levothyroxine
-> primary + secondary hypothyroidism
-> long duration (3 weeks)

T3 replacement: liothyronine
-> short duration (3 days)

Question 7

Adverse effects of levothyroxine + liothyronine

Answer 7

• hyperthyroidism
• increased CV effects (similar to those in hyperthyroidism)
• increased osteoporosis risk

Question 8

2 classes of hypothyroidism + what differentiates them

Answer 8

primary hypothyroidism: increased TSH but decreased TH
eg. hashimoto’s

secondary hypothyroidism: reduced TSH + TH
eg. hypothalamic/pituitary dysfunction

Question 9

2 classes of adrenal insufficiency + what differentiates them

Answer 9

Primary adrenal insufficiency (addison’s disease): autoimmune destruction of cortex

Secondary adrenal insufficiency:
- pituitary X produce enough ACTH to make steroid hormones such as cortisol

Question 10

2 classes of drugs that can treat adrenal insufficiency

Answer 10

• glucocorticoids (cortisone, hydrocortisone + prednisolone)
• mineralocorticoid (fludrocortisone)

Question 11

Fludrocortisone indications + adverse effects

Answer 11

• primary adrenal insufficiency where aldosterone is low
• orthostatic hypotension (b/c fluid retaining properties)

adverse effects: sodium + water retention
- hypertension + oedema

Question 12

Cushing’s disease causes + goals of treatments

Answer 12

• overproduction of cortisol by pituitary
• excess ACTH

Goal: return cortisol levels to normal
- block release of cortisol
- block ACTH release
- block cortisol effects in body

Question 13

Adverse effects of glucocorticoids

Answer 13

• adrenocortical insufficiency
• diabetes mellitus
• impaired wound healing
• hypertension

Question 14

how to reduce undesired effects of corticosteroids

Answer 14

• lowest dose for shortest duration
• only use when needed
• give in morning + locally
• taper if ceasing