MCQ's: Diabetic Drugs

Question 1

Metformin:

1. Metabolised in?

Answer 1

Not metabolised, excreted unchanged in the urine. Undetectable in the plasma at 24 hours after a single dose.

Question 2

What class of drug is metformin? What’s it’s mechanism of action?

Answer 2

A biguanide hypoglycaemic.
Enhances peripheral action of endogenous insulin.

Therefore decrease intestinal glucose uptake and decreases peripheral glucose utilisation.

Question 3

What is metformins half life?
Time to peak concentration?
Duration of action?

Answer 3

6 hours.

Peak concentration at 1-3 hours.

Duration of action 8-12 hours.

Question 4

True or false: Biguanides stimulate pancreatic insulin release?

Answer 4

False.

They decrease gluconeogenesis.
Increase glycolysis.
Decrease glucose absorption intestinally.

Question 5

What type of diabetics is metformin used in?

Answer 5

Adult onset diabetes.

Young diabetics on insulin can precipitate ketonuria if treated with biguanides as well.

Question 6

Protein binding of metformin?

Answer 6

Neglible protein binding.

Question 7

Mechanism of action if sulfanylureas?

Answer 7

Increase insulin secretion but do not affect production. Bind to a receptor coupled to increase Calcium entry into pancreatic beta cells.
They displace insulin from pancreatic islet 13 cells.

Enhance insulin’s ability to glucose uptake into muscle and fat cells.

Question 8

Examples of sulfanylureas?

Answer 8

Glibenclamide, tolbutamide, chloroproramide.

Question 9

Effect on thiazides on hypoglycaemia induced by sulfanylureas?

Answer 9

Thiazides antagonise effect of hypoglycaemia.

Question 10

haematological side effects of sulfanylureas?

Answer 10

Leucopenia, agranulocytosis, thrombocytopenia caused by tolbutamide and chloropropramide.

Question 11

T/ F:
1. Gliclazide- protects beta cells from hyperglycaemic damage.

2. Gliclazide- reduces atheromatous plaque build up.
3. Chlorpropramide is metabolised and excreted by the kidney

Answer 11

1. True
2. True
3. False. Chlorpropramide undergoes no significant metabolism and is excreted very slowly, largely unchanged in the urine.

Question 12

Insulin pH?

Answer 12

pH 7, neutral insulin

Question 13

True or false:

60-80% of insulin can be lost due to binding to the IV fluid container and tubing.

Answer 13

True

Question 14

What percentage of secreted insulin is degraded and where?

Answer 14

80% in the liver and kidneys

Hepatic glutathione transhydrogenase breaks insulin molecule down to its constituent peptide chains.

Question 15

Half life of endogenous insulin?

Answer 15

10-20 minutes

Question 16

T/F regarding insulin:
1. It’s action involves 2nd messenger

2. Polypeptide if 4 chains
3. Increase cAMP in the liver
4. Increase K+ uptake into cells
5. Increases protein synthesis in ribosomes

Answer 16

1. True
2. False- formed of 2 chains. Alpha and beta.
3. False.
4. True
5. True

Question 17

Insulin effect on cAMP in liver?

Answer 17

Reduced cAMP - this actively decreases potassium in hyperkalaemia.

Question 18

What hormone does insulin inhibit?

Answer 18

Lipase

Question 19

Insulin facilitates glucose uptake into?

Answer 19

The pituitary, peripheral tissue (fat/ muscle), fibroblasts, liver.

Question 20

Molecular form of insulin?

Answer 20

Molecular weight of 5600 Da

Comprised of two polypeptides alpha and beta that are strongly bound by 2 covalently bonded disulphide bridges.

Question 21

Insulin can be blocked by which drug?

Answer 21

Atropine

Question 22

What PDE inhibitor can stimulate insulin?

Answer 22

Theophylline

Question 23

Effect of A2 and B2 agonists on insulin?

Answer 23

A2- decrease insulin secretion

B2- increase insulin secretion

Question 24

Sulfanylureas tend to cause weight loss? T/F

Answer 24

False

Question 25

Sulfanylureas have a shorter or longer half life than biguanides?

Answer 25

Longer half lives than biguanides

Question 26

Which diabetic medication can cause ketonuria?

Answer 26

Metformin

Question 27

Insulin secretion can be blocked by which drug?

Answer 27

Atropine

Question 28

Which amino acids stimulate insulin release?

Answer 28

Leucine and Arginine

Question 29

What hormone can inhibit insulin secretion?

Answer 29

Somatostatin

Question 30

How does insulin affect cAMP?

Answer 30

Decreases cAMP in the liver