90 - Oral Hypoglycaemic Agents

Question 1

Blood glucose regulating organ that responds directly to plasma glucose levels, not to hypothalamic-pituitary axis

Answer 1

Pancreas

Question 2

Role of pancreatic acinar cells

Answer 2

Exocrine.

Release digestive fluid into gut.

Question 3

Role of pancreatic delta cells

Answer 3

Release somatostatin

Question 4

Macronutrient, other than carbohydrates, that is affected by DM

Answer 4

Lipid metabolism

Question 5

Normal shape of blood [insulin] graph over time

Answer 5

Two peaks after ingesting carbohydrates.
First spike, ~5 minutes after ingesting sugar, is quite high.
Then second spike afterwards to regulate breakdown of more complex carbohydrates.

Question 6

Adverse effect of high levels of sulphonamides

Answer 6

Convulsions, coma, hypoglycaemia.

Stimulates insulin release.

Question 7

First oral hypoglycaemic

Answer 7

2254RP sulphonamide.

Stimulates insulin release from the pancreas.

Question 8

Mechanism of sulphonylurea stimulation of pancras

Answer 8

Inhibits ATP-sensitive K+ channel.
Leads to cellular depolarisation, Ca2+ entry.
This stimulates insulin release from pancreas.

Question 9

How do islet beta cells detect glucose levels?

Answer 9

Have GLUT2 transporter.
Glucose is taken up, converted to ATP.
K+ channel is sensitive to ATP (is closed when ATP binds to it).

Question 10

Effect of sulphonylureas

Answer 10

Oral hypoglycaemic agents (derived from sulphonamides)

Question 11

Half life of sulphonylureas

Answer 11

6-24 hours

Question 12

Why can’t sulphonylureas be used in pregnancy?

Answer 12

Can cross placenta

Question 13

How are sulphonylureas excreted?

Answer 13

Via kidneys

Question 14

Adverse effects of sulphonylureas

Answer 14

Weight gain

Hypoglycaemia

Question 15

Example of a biguanide

Answer 15

Metformin

Question 16

Actions of metformin

1-4

Answer 16

– Increase insulin-mediated peripheral glucose uptake
– Reduce hepatic glucose production.
– Decrease carbohydrate absorption
– Reduce LDL cholesterol level and triglycerides

Question 17

Adverse effects of metformin

1-4

Answer 17

– GI disturbances: diarrhoea, nausea, abdominal
discomfort & anorexia
– Lactic acidosis if improperly prescribed
– No weight gain, with possible modest weight loss
– Contraindicated in patients with impaired renal
function

Question 18

Mechanism of action of metformin

Answer 18

Activates AMP kinase

Question 19

Drugs used for T2DM with a relative lack of insulin

Answer 19

Drugs which give an increase in insulin in the blood

Sulphonylureas
Meglitinides

Question 20

Drugs used for T2DM with insulin resistance

Answer 20

Biguanidines
Thiazolidinediones (withdrawn in Australia, drug interactions can cause severe liver disease)

Question 21

Example of an alpha-glucosidase inhibitor

Answer 21

Acarbose

Question 22

Mechanism of action of alpha-glucosidase inhibitors

Answer 22

Block the enzymes that digest and promote absorption of starches in the small intestine.
Blocks glucose absorption.

Question 23

Adverse effects of acarbose
1
2
3

Answer 23

– Flatulence or abdominal discomfort
– Loose stools & abdominal pain
– Contraindicated in patients with inflammatory
bowel disease or cirrhosis

Question 24

When are alpha-glucosidase inhibitors administered?

Answer 24

Only when other options don’t work

Question 25

Role of incretin hormones

Answer 25

Released from gut, stimulates beta cells to release insulin, inhibits alpha cell glucagon secretion

Question 26

Enzyme that degrades incretins

Answer 26

DPP-4.

Question 27

T2DM drugs that affect incretin levels

Answer 27

Dipeptidyl peptidase 4 (DPP4) inhibitors

Question 28

Role of DPP4 inhibitors

Answer 28

As an adjunct to healthy diet and exercise.

For early T2DM

Question 29

Adverse effects of DPP4 inhibitors

1-5

Answer 29

• URT infections
• Headaches
• Hypoglycaemia when combined with other T2DM drugs
• Allergic reactions
• Pancreatitis (can be fatal)

Question 30

Effects of glucagon-like polypeptide receptor agonists

1-4

Answer 30

• Potentiate glucose-mediated insulin secretion
• Suppress glucagon release
• Slow gastric emptying
• Loss of appetite (central action)

Question 31

Adverse effects of GLP-1 agonists

1-4

Answer 31

• Nausea, vomiting, diarrohea
• Weight loss (anorectic)
• Antibody formation, immune reactions, pancreatitis,
• Endocrine neoplasias (rodents)

Question 32

Drug class that affects glucose reabsorption

Answer 32

Sodium-glucose cotransporter 2 inhibitors (SGLT2 inhibitors)