Endocrinology drugs

Question 1

How does insulin work?

Answer 1

Its a peptide hormone, lowers plasma glucose conc by stimulating glucose transport into fat and muscle, stimulates glycogen synthesis and inhibits gluconeogenesis

Question 2

What is insulin’s relationship with potassium?

Answer 2

Causes potassium influx causing low plasma K+ conc, which is why it is used in emergency treatment of hyperkalaemia

Question 3

What class of drug is gliclazide?

Answer 3

Sulfonylureas

Question 4

How does gliclazide work?

Answer 4

Stimulates insulin production by binding to sulfonylurea receptors and blocking K+ channels in pancreatic B cells causing depolarisation and insulin release

Question 5

What is required for gliclazide to work?

Answer 5

Residual B cell activity and therefore endogenous insulin

Question 6

What class of drug is metformin?

Answer 6

Biguanides

Question 7

How does metformin work?

Answer 7

Increases glucose utilization, decreases gluconeogenesis and GI glucose absorption

Question 8

What indication do insulin, gliclazide and metformin have in common?

Answer 8

Type 2 Diabetes Mellitus

Question 9

What is there an increased risk of when alcohol is used with metformin?

Answer 9

Lactic acidosis

Question 10

Why is metformin the treatment of choice in obese patients?

Answer 10

It also decreases apetite

Question 11

How does thyroxine work?

Answer 11

Mimics endogenous thyroxine, increases oxygen consumption of metabolically active tissues

Question 12

What drug interactions does thyroxine have?

Answer 12

Increases warfarin effect, faster response to TCAs, faster metabolism of beta blockers

Question 13

What drug is used in hyperthyroidism?

Answer 13

Carbimazole

Question 14

How does carbimazole work?

Answer 14

Inhibits thyroid peroxidase which is responsible for thyroid hormone synthesis resulting in decreased production of T3 and T4.

Question 15

When carbimazole is used for Graves’ disease, how long should treatment be continued for?

Answer 15

At least a year, when on carbimazole, regular monitoring is needed

Question 16

What class of drug is alendronate?

Answer 16

Bisphophonates

Question 17

How does alendronate work?

Answer 17

Inhibits osteoclast mediated bone resorption, need vitamin D and calcium to promote normal bone development

Question 18

Indications for alendronate?

Answer 18

Osteoporosis

Question 19

Contraindications for alendronate?

Answer 19

Abnormalities of the oesophagus and other factors delaying emptying, hypoglycaemia

Question 20

How do antacids effect absorption of alendronate?

Answer 20

Decrease it

Question 21

What important information should the patient be given when on alendronate?

Answer 21

Avoid taking other medicines or food for at least 30 mins after taking it to prevent altered absorption. Also need to sit/stand for 30 mins after taking it.

Question 22

What drug class is fludrocortisone?

Answer 22

Mineralocorticosteroids

Question 23

How does fludrocortisone work?

Answer 23

Binds mineralocorticosteroid (Aldosterone) receptor to increase ECF and blood pressure, retain Na+ and H2O and reduce K+ levels

Question 24

Indications for fludrocortisone use?

Answer 24

Adrenocortical insufficiency/Addison’s disease

Question 25

When can fludrocortisone not be used?

Answer 25

Systemic infections (particularly fungal)

Question 26

What can develop if fludrocortisone is given in high doses?

Answer 26

Cushing’s syndrome

Question 27

Why should reduction of fludrocortisone dose be gradual?

Answer 27

Too rapid a reduction can cause adrenal insufficiency, hypotension and death