Pharmacology

Question 1

What are the five main actions of insulin?

Answer 1

• induces glucose uptake & utilisation
• lowers blood glucose
• promotes formation of glycogen (storage)
• promotes conversion of glucose into fat in adipose
• stimulates amino avid uptake & protein formation

Question 2

Name four drugs classes that act to reduce insulin secretion

Answer 2

• sulfonylureas
• incretin analogues
• DDP-4 Inhibitors

Question 3

Name two drug classes that decrease insulin resistance

Answer 3

• biguanides

- thiazolidinediones

Question 4

What two drug classes are independent on insulin?

Answer 4

alpha glucosidase inhibitor (slow absorption) & SGLT2 inhibitors (enhance excretion)

Question 5

Describe the action of sulfonylureas

Answer 5

Promote insulin secretion by acting on KATP channels in beta cells. By binding to the SUR1 unit they close the channel leading to depolarisation and vesicle release.

Question 6

Name examples of sufonylureas

Answer 6

• gliclazide/tolbutamide

- glipizide

Question 7

What are the side effects of sulfonylureas?

Answer 7

Hypoglycaemia & weight gain

Question 8

When are sulfonylureas contraindicated?

Answer 8

Renal impairment, elderly, pregnancy

Question 9

Describe the physiology of incretins

Answer 9

• Ingestion of food stimulates glucagon like peptide (GLP1) and Glucose dependent insulinotropic peptide (GIP) from enteroendocrine cells in the small intestine.
• GIP and GLP1 enter the portal blood
• As a result they enhance insulin release from beta cells to increase glucose uptake & decrease glucagon release from alpha cells to decrease glucose productions

Question 10

What enzyme inhibits incretins?

Answer 10

DDP-4

Question 11

Name two incretin analogues

Answer 11

extenatide & liraglutide

Question 12

How are incretin analogues administered?

Answer 12

subcutaneously

Question 13

Name examples of DDP-4 inhibitors

Answer 13

silagliptin, saxaglipin, vildagliptin

Question 14

What do alpha glucosidase inhibitors do?

Answer 14

Inhibit alpha glucosidase the brush border enzyme that breaks down carbs to absorbable glucose. Inhibitors act to prevent/delay glucose absorption

Question 15

Are alpha glucosidase inhibitors commonly used in the UK?

Answer 15

No

Question 16

What drug is a biguanide?

Answer 16

Meformin

Question 17

What does metformin act to do?

Answer 17

• decrease hepatic gluconeogenesis
• decrease carbohydrate absorption
• increase glucose uptake & utilisation
• increase fatty acid oxidation

Question 18

What are the side effects of metformin?

Answer 18

GI disturbance/lactic acidosis

Question 19

Clinically what is metformin useful for?

Answer 19

reducing microvascular complications, preventing hypoglycaemia, helps with weight loss

Question 20

Name an example of a thiazolidinediones

Answer 20

pioglitazone

Question 21

How do thiazolidinediones work?

Answer 21

Enhance insulin action at target tissues but acting as an exogenous agonist of nuclear receptors that act as transcription factors for proteins involved in insulin signalling & lipid metabolism

Question 22

What are the side effects of thiazolidinediones?

Answer 22

weight gain, fluid retention, hepatotoxicity & bone fractures

Question 23

How do sodium glucose cotransporter 2 inhibitors work?

Answer 23

Act selectively to block the reabsorption of glucose by SGLT2 in the proximal tubule causing glycosuria

Question 24

Name an example of an SGLT 2 inhibitor

Answer 24

Empagliflozin