Sulphonylureas

Question 1

What are examples of sulphonylureas?

Answer 1

• Gliclazide
• Glimpiride
• Glipizide

Question 2

What are contraindications to sulphonylurea use?

Answer 2

• Acute porphyria (Gliclazide only)
• Presence of Ketoacidosis
• Severe hepatic/renal impairment
• Risk of hypos

Question 3

When would you use sulphonylureas with caution?

Answer 3

• Renal impairment
• Hepatic impairment
• Pregnancy and breast feeding
• Elderly
• G6PD Deficiency

Question 4

What is the mechanism of action of sulphonylureas?

Answer 4

Increase insulin secretion from pancreatic islet cells - need residual beta cells. They block ATP-dependent K+ channels in pancreatic β-cell membranes, causing depolarisation of the cell membrane and opening of voltage-gated Ca2+ channels. This increases intracellular Ca2+ concentrations, stimulating insulin secretion

Question 5

Are sulphonylureas associated with weight gain?

Answer 5

Yes

Question 6

What are adverse side effects of sulphonylureas?

Answer 6

• Hypoglycaemia
• Weight gain
• Gastro-intestinal upset
• Hepatic impairment
• Hypersensitivity reaction (rash, liver disease)
• Rarely haematological abnormalities

Question 7

What are people taking sulphonylureas at risk of?

Answer 7

Hypoglycaemia

Question 8

What are the easiest sulphonylureas to use?

Answer 8

Those which are shorter duration of action and hepatically metabolised e.g. gliclazide

Question 9

When should sulphonylureas be taken?

Answer 9

With meals

Question 10

Why may insulin be required in acute illness in hospital inpatientsfor someone on sulphonylureas?

Answer 10

Acute illness can precipitate side effects, and insulin can be more easily controlled in response to acute fluctuations in blood sugar