Insulin & Anti-glycaemic Agents

Question 1

Describe the types of diabetes and their consequences

Answer 1

Metabolic disease of chronic hyperglycaemia
Type I (IDDM) results from autoimmune destruction of beta cells
Type 2 (NIDDM) results from insulin resistance and reduced
insulin production

DM results in:
Macrovascular damage (increased risk of IHD, stroke, and PVD)
Microvascular damage (increased risk of retinopathies,
neuropathies, nephropathies, and infections)

Question 2

Describe the management of type 1 diabetes

Answer 2

SC insulin injections can be given, for which there are two main
mixtures:
Basal Bolus Regimen - involves a long acting insulin as background and then a fast acting insulin with meals
Involves injecting around 5 times a day

Pre-mixed Insulin Regime - involves administration of both fast
and slow acting insulin twice a day.
Does not provide optimised glycaemic control yet involves less
injecting for the patient

Question 3

What is the overall aim of management of type 2 diabetes

Answer 3

Number of drug groups used to treat NIDDM
All taken orally
Generally, all will reduce the HbAlc by 1-2°/.
Given concurrently, are not as effective but may provide additional help

Question 4

What are the 3 main classes of drugs used to treat type 2 diabetes

Answer 4

Biguanides
Thiazonlidinediones (TZDs)
Sulphonylureas

Question 5

Biguanides:
Main drug in this class
Mechanism of action
Advantage
ADRs/contraindications

Answer 5

Metformin is first line therapy

Acts by increasing cells sensitivity to insulin and inhibits hepatic gluconeogenesis
Does not undergo any metabolism and is directly renally excreted

The drug is cheap and does not cause hypoglycaemia

ADRs: GI disturbances and contraindicated in compromised HRH

Question 6

Thiazonlidinediones (TZDs):
2 main types
Mechanism of action
ADRs 
Contraindications/DDI

Answer 6

Rosiglitazone and Pioglitazone

Act by reducing gluconeogenesis and increasing glucose uptake in muscles

ADRs: weight gain, increase LDLs and HDLs, and cause oedema

Act as precipitant drug so avoid use with Warfarin

Question 7

Sulphonylureas:
2 main types
Mechanism of action
ADRs
Contraindication/DDI

Answer 7

gliclazide or tolbutamide

Act by antagonising the Beta cells K+-ATP channel activity. This
depolarises the cell and thus increases Ca2+ ion entry, increasing
insulin release from the cells

ADRs: incidence of hypoglycaemic episodes, weight gain, and Gl
distrubances

Also act as precipitant drug to Warfarin

Question 8

Describe general management techniques for diabetes

Answer 8

Diet changes
Increase exercise
Reduce CVS risk factors (e.g. Hyperlipidaemia or HTN)

Education programmes:
DAFNE for type I diabetes and DESMOND for type 2
diabetes

Home HbAlc monitoring

Question 9

What are the mechanisms of action for insulin

Answer 9

acts on insulin receptors

Activates GLUT4 to relocate to the cell surface and increase glucose
uptake

Also acts to:
• Inhibit glycogen breakdown and enhance uptake to the liver
• Stimulate fatty acid synthesis and inhibit lipolysis
• Inhibit proteolysis