Antidiabetics - Sulfonylurea

Question 1

Beta cells of the pancreas are sensitive to blood glucose. What transporter transports glucose into beta cells?

1 - GLUT-4
2 - GLUT-3
3 - GLUT-2
4 - GLUT-1

Answer 1

3 - GLUT-2

• once inside the beta cell glucose is metabolised into ATP

Question 2

Once glucose enters the cell through GLUT-2 it is metabolised to ATP. Which channel on the beta cell is sensitive to ATP levels and closes in the presence of high ATP?

1 - Na+/K+ ATPase
2 - Na+
3 - K+
4 - Cl-

Answer 2

3 - K+
- intracellular K+ will then begin to rise
- cellular depolarisation occurs

Question 3

Once glucose enters the cell through GLUT-2 it is metabolised to ATP, causing ATP sensitive K+ channels to close and cause depolarisation. Depolarisation then leads to a voltage gated channel to open. Which channel is this?

1 - Na+/K+ ATPase
2 - Na+
3 - K+
4 - Ca2+

Answer 3

4 - Ca2+
- increases intracellular Ca2+
- increased Ca2+ causes insulin filled vesicles to fuse with the beta cell and release insulin

Question 4

Sulfonylurea is a class of anti-diabetic medication. What is the name of the drug in this class that we need to know?

1 - Gliclazide
2 - Metformin
3 - Dapagliflozin
4 - Dulaglutide

Answer 4

1 - Gliclazide

Question 5

What is the mechanism of action of the drug group sulphonylureas, with the drug we need to know Gliclazide?

1 - inhibits ATP sensitive K+ channels from opening
2 - inhibition of a-glucosidase
3 - inhibit sodium-dependent glucose co-transporters
4 - reduces hepatic gluconeogenesis

Answer 5

1 - inhibits ATP sensitive K+ channels from opening

• K+ remains in cell and cell depolarises
• Ca2+ enters cell and signals the release of insulin

Question 6

Sulphonylureas are an anti-diabetic medication, with the drug we need to know being Gliclazide. Is Gliclazide a 1st line treatment for hyperglycaemia in T2DM?

Answer 6

• no

Question 7

Sulphonylureas are an anti-diabetic medication, with the drug we need to know being Gliclazide. When can Gliclazide be used for treatment for hyperglycaemia in T2DM?

1 - if metformin is not tolerated
2 - part of dual therapy
3 - part of triple therapy
4 - all of the above

Answer 7

4 - all of the above

• if metformin is not tolerated other anti-diabetic medications can be used
• essentially can be added to other anti-diabetic medication if HbA1c >58mmol/mol

Question 8

Sulphonylureas are an anti-diabetic medication, with the drug we need to know being Gliclazide. Is Gliclazide effective for all T2DM patients?

Answer 8

• no
• must have residual beta cell function

Question 9

Sulphonylureas are an anti-diabetic medication, with the drug we need to know being Gliclazide. What can long term use of Gliclazide cause?

1 - weight gain as insulin is anabolic hormone
2 - decline in beta cell function
3 - insulin resistance due to weight gain
4 - all of the above

Answer 9

4 - all of the above

Question 10

Which of the following are adverse events of sulphonylureas, with the drug we need to know Gliclazide?

1 - GI upset
2 - hypoglycaemia
3 - hypersensitive reactions
4 - all of the above

Answer 10

4 - all of the above

• GI upset and hypoglycaemia are dose dependent
• hypoglycaemia is rare but severe
• hypersensitive reactions, such as hepatic toxicity or agranulocytosis

Question 11

Where Gliclazide, a sulphonylurea metabolised?

1 - liver
2 - GIT
3 - kidney
4 - pancreas

Answer 11

1 - liver
- has half life of 10-12 hours

Question 11

Where Gliclazide, a sulphonylurea excreted from?

1 - liver
2 - GIT
3 - kidney
4 - pancreas

Answer 11

3 - kidney
- unchanged drug and metabolites excreted here

Question 12

Why might a patient need a lower dose of Gliclazide, a sulphonylurea?

1 - beta cell function is good
2 - low insulin resistance
3 - renal/hepatic impairment
4 - HbA1c is <48mmol/mol

Answer 12

3 - renal/hepatic impairment

• metabolised by liver
• excreted by kidney

Question 13

Which of the following if combined with Gliclazide, a sulphonylurea can increase the risk of hypoglycaemia?

1 - metformin
2 - insulin
3 - DPP-4 inhibitors
4 - SGLT-2 inhibitors
5 - alcohol
6 - all of the above

Answer 13

6 - all of the above

• all can already cause hypoglycaemia
• together this risk is increased

Question 14

Which medication can mask the effects of hypoglycaemia that may occur in a patient taking Gliclazide, a sulphonylurea?

1 - ACE inhibitor
2 - B-blocker
3 - A-blocker
4 - Ca2+ channel blocker

Answer 14

2 - B-blocker

Question 15

Some drugs can raise blood glucose, such as prednisolone, thiazide and loop diuretics. What effect can this have on the efficacy of Gliclazide, a sulphonylurea?

Answer 15

• dampens the efficacy
• drug is not as effective

Question 16

What is typically a starting dose of Gliclazide, a sulphonylurea?

1 - 10-20mg OD
2 - 20-40mg OD
3 - 40-80mg OD
4 - 160-320mg OD

Answer 16

3 - 40-80mg OD

• start low and titrate up to 160-320mg, based on HbA1c
• higher doses of 160-320mg should be spread over separate times in the day

Question 17

When should Gliclazide, a sulphonylurea typically be taken?

1 - morning
2 - lunch
3 - evening
4 - with meals

Answer 17

4 - with meals

• always warn about signs of hypoglycaemia

Question 18

The typical target for HbA1c is 48 mmol/mol. However, if a patients HbA1c is still uncontrolled and >58 mmol/mol, what is typically the target?

1 - <44 mmol/mol
2 - <48mmol/mol
3 - <53mmol/mol
4 - <58mmol/mol

Answer 18

3 - <53mmol/mol