Antidiabetic drugs

Question 1

What is the MOA of metformin?

Answer 1

1st line and drug of choice for this patient as his BMI is high and it does not cause weight gain

• 500mg OD with breakfast
• Decreases gluconeogenesis (generation of glucose)
• Increases peripheral utilisation of glucose
• Decreases insulin resistance
• Stimulates glycolysis in tissues
• s/e  diarrhoea and metallic taste

Question 2

What is the MOA of sulphonylurea and give an example?

Answer 2

Gliclazide

• Increases insulin secretion and binds to sulphonylurea receptors on pancreatic beta cells
• These receptors increase intracellular levels of ATP which inhibits potassium channels. This results in calcium influx and the stimulation of insulin exocytosis into the blood stream
• Stimulates appetite and causes weight gain

Question 3

What is the MOA of gliptins and give an example?

Answer 3

Sigagliptin

DPP-4 inhibitors

Dipeptidyl peptidase inhibitors

• Increases glucagon-like peptide 1 levels which increase insulin production and decreases the release of glucose from the liver
• s/e - pancreatitis, hypoglycaemia

Question 4

What is the MOA of thiazolidinediones and give an example?

Answer 4

Pioglitazone

• Agonist for PPAR
• Stimulates insulin secretion from pancreas
• Increases insulin sensitisation in skeletal muscle
• Decreases glucose production in the liver
• Needs insulin to be effective and it reduces insulin resistance in peripheral tissues
• Weight gain due to increased fluid absorption

Question 5

What is the MOA of sodium glucose cotransporter-2 inhibitors and give an example?

Answer 5

• Dapagliflozin
• Blocks reabsorption (reuptake) of glucose in the kidneys so promotes the excretion of XS glucose in the urine
• Can cause hypovolaemia

Question 6

What is the MOA of incretin mimetics (GLP-1 analogues)?

Answer 6

• Mimics anti-hyperglycaemic effects of GLP-1
• Enhances glucose-dependent insulin secretion
• Promotes fullness so reduces body weight

Question 7

What is the MOA of alpha glucosidase inhibitors and give an example?

Answer 7

Acarbose

• Slows absorption of glucose from intestine
• Delays starch digestion and inhibits carbohydrate breakdown and reduces postpandrial increase in blood glucose levels

Question 8

What is the MOA of meglitinides and give an example?

Answer 8

Repaglinide

• Increases insulin secretion
• Rapid onset
• Closes potassium channels on beta cells which indirectly results in exocytosis of insulin into blood

Question 9

What is the MOA of amylin analogues?

Answer 9

• Inhibits glucagon release

- Decreases gastric emptying and decreases food intake