Diabetes pharmacology

Question 1

Mechanisms of insulin therapy

Answer 1

Insulin binds to tyrosine kinase receptors where it initiates 2 pathways by phosphorylation:
MAP kinase signalling pathway
PI-3K signalling pathway

Question 2

What is the purpose of the MAP kinase signalling pathway (insulin therapy)

Answer 2

Responsible for cell growth a proliferation

Question 3

What is the purpose of the PI-3K signalling pathway (insulin therapy)

Answer 3

Responsible for the transport of GLUT-4 receptors to the cell surface membrane
GLUT-4 transports glucose into the cell

This pathway is also responsible for protein, lipid and glycogen synthesis

Question 4

Side-effects of insulin therapy

Answer 4

Weight gain
Hypoglycaemia
Localised lipoatrophy
Hypokalemia

Question 5

Contraindications of insulin

Answer 5

Hypersensitivity to any of ingredients of therapy

Hypoglycaemia

Question 6

Drug interactions

Answer 6

Thiazide diuretics (decrease effect of insulin)
Corticosteroids
Repaglinide
Monoamine oxidase inhibitors
Levothyroxine (decreases effect of insulin)

Question 7

Example of biguanide

Answer 7

Metformin

Question 8

Mechanisms of metformin/biguanide action

Answer 8

Increased peripheral insulin sensitivity
Increased glucose uptake into and use by skeletal muscle
Decreased hepatic gluconeogenesis
Decreased intestinal glucose absorption

Question 9

Other use of Metformin, other than type 2 diabetes

Answer 9

Polycystic ovarian syndrome

Question 10

Side effects of metformin

Answer 10

GI tract disturbance e.g. diarrhoea
N/V
Lactic acidosis

Question 11

Contraindications of metformin

Answer 11

Renal failure
Cardiac failure
Respiratory failure
Hepatic failure

Question 12

Drug Interactions of metformin

Answer 12

Contrast agents
ACE inhibitors
NSAIDs
Steroids

Question 13

Example of sulphonylurea

Answer 13

Glipzide

Question 14

Mechanism of sulphonylurea action

Answer 14

Stimulates release of insulin by blocking potassium channels on pancreatic beta cells

Question 15

Side effects of sulphonylurea

Answer 15

GI disturbance
Hypoglycaemia
Weight gain

Question 16

Contraindications of sulphonylurea

Answer 16

Renal failure
Hepatic failure
Porphyria
Pregnancy
Breastfeeding

Question 17

Drug interactions of sulphonylurea

Answer 17

ACE inhibitors
Alcohol
NSAIDs
Steroids

Question 18

Example of meglitinides (glinides)

Answer 18

Repaglinide

Question 19

Mechanism of action of meglitinides

Answer 19

Block potassium channels on the pancreatic beta cells thus stimulating insulin release

Question 20

Side effects of meglitinides

Answer 20

Weight gain

Hypoglycaemia

Question 21

Examples of Incretins and how they work

Answer 21

Exenatide - analogue of glucagon-like peptide (GLP-1)

Saxagliptin - inhibits dipeptidyl peptidase (DPP-4)