Sulphonylureas (Gliclazide)

Question 1

What is Gliclazide (sulphonylureas) used for?

Answer 1

TYPE 2 DIABETES MELLITUS
(to control blood sugars when metformin is not tolerated or contraindicated)
OR used in combo with metformin / other hypoglycaemic agents when blood glucose not controlled.

Question 2

How does gliclazide (a sulphonylureas) work>

Answer 2

• Gliclazide lowers blood glucose by stimulating pancreatic insulin secretion.
• the drug blocks ATP-dependany K+ channels in pancreatic b cell membranes.
• depolarisation causes opening of Ca2+ channels.
• Ca2+ inside cell increased —–> insulin secretion.

Question 3

Why are sulphonylureases worse in the long term?

Answer 3

Sulphonylureas stimulates secretion of insulin.

This is associated with weight gain and can worsen DM in the long term.

Question 4

What are the side effects of gliclazide (sulphonylurease)

Answer 4

• GI upset (nausea, vomiting, diarrhoe, constipation)
• Hypoglycaemia
• rare Hypersensitivity (allergic reaction) —-> hepatic toxicity e.g. cholestatic jaundice.
• Drug hypersensitivity sydrome —> rash, fever

Question 5

What is the plasma half life of the gliclazide and where is it metabolised?

Answer 5

Gliclazide is metabolised in the liver and has a plasma half life of 10-12 hours.

Question 6

What patients should there be a dose reduction of gliclazide?

Answer 6

Hepatic impairment should have dose reduction because it is metabolised in the liver.

Question 7

Why should blood glucose be monitored carefully in patients with renal impairment who take gliclazide?

Answer 7

The unchanged drug and its metabolites are excreted via the kidneys. In patients with renal impairment this may not happen efficiently so the drug remains in the system for longer.

Question 8

What are the drug interactions of sulphonylureas (gliclazide)?

Answer 8

• Risk of hypoglycaemia with other antidiabetic drugs e.g. metformin, thiazolidinediones and insulin.
• the efficacy of glicliazide is reduced by drugs that to raise blood glucose e.g. prednisoline, thiazide, loop diuretics.

Question 9

how is gliclazide taken?

Answer 9

orally with meals

Question 10

What is the starting dose of gliclazide?

Answer 10

40-80mg

Question 11

How shoudl gliclazide be monitored?

Answer 11

-HbA1c (target <58mmol/l)
- renal and liver function before treatment starts.
(blood glucose doesnt need regular monitoring)