Antidiabetics - DPP4 inhibitors

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

Incretins are a group of hormones responsible for reducing blood glucose, such as glucagon like peptide-1 (GLP-1). Enteroendocrine cells are specialised cells that are able to release incretins. Which 2 of the following are the locations where enteroendocrine cells can be located?

1 - pancreas
2 - stomach
3 - liver
4 - ileum/colon

Answer 4

1 - pancreas
4 - ileum/colon

Question 5

Incretins can be degraded by what enzyme?

1 - dipeptidyl peptidase 4
2 - pancreatic lipase
3 - beta-amyloid peptide
4 - all of the above

Answer 5

1 - dipeptidyl peptidase 4

• DPP-4 inhibitors inhibit this enzyme
• means more incretins are available

Question 6

What are the 2 core dipeptidyl peptidase 4 (DPP-4) inhibitors we need to know?

1 - Sitagliptin
2 - Metformin
3 - Dapagliflozin
4 - Linagliptin

Answer 6

1 - Sitagliptin
4 - Linagliptin

Question 7

Dipeptidyl peptidase 4 (DPP-4) inhibitors, Sitagliptin and Linagliptin are an anti-diabetic medication. When can DPP-4 inhibitors 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

Why are (DPP-4) inhibitors, Sitagliptin and Linagliptin and GLP-1 agonists, Dulaglutide Exenatide less likley to cause hypoglycaemia as much as Gliclazide the Sulfonylurea?

1 - not as potent
2 - dont leave the GIT
3 - glucose dependent response
4 - increase glucagon and insulin levels

Answer 8

3 - glucose dependent response
- low glucose means low insulin
- high glucose means high insulin

Question 9

Hypoglycaemia is rare when using DPP-4 inhibitors, Sitagliptin and Linagliptin. However, if DPP-4 inhibitors are combined with specific drugs, this can increase the risk of Hypoglycaemia. Which 2 of the following can do this?

1 - sulphonylures
2 - insulin
3 - GLP-1
4 - Beta-blockers

Answer 9

1 - sulphonylures
2 - insulin

• both can cause Hypoglycaemia so combined with DPP-4 can increase the risk of Hypoglycaemia

Question 10

DPP-4 inhibitors, Sitagliptin and Linagliptin, in rare can cause inflammation of which organ?

1 - hepatitis (liver)
2 - pancreatitis (pancreas)
3 - glomerulonephritis (kidney)
4 - myocarditis (heart)

Answer 10

2 - pancreatitis (pancreas)

Question 11

Which of the following are common adverse events DPP-4 inhibitors of Sitagliptin and Linagliptine?

1 - GI upset
2 - headaches
3 - nasopharyngitis
4 - peripheral oedema
5 - all of the above

Answer 11

5 - all of the above

Question 12

Which of the following are DPP-4 inhibitors, Sitagliptin and Linagliptin contraindicated in?

1 - T1DM
2 - DKA
3 - hypersensitivity
4 - pregnancy/breastfeeding
5 - history of pancreatitis
6 - all of the above

Answer 12

4 - all of the above

Question 13

Why might a patient need a lower dose of DPP-4 inhibitors, Sitagliptin and Linagliptin?

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

Answer 13

3 - renal/hepatic impairment

• metabolised by liver
• excreted by kidney

Question 14

Which medication can mask the effects of hypoglycaemia that may occur in a patient taking DPP-4 inhibitors, Sitagliptin and Linagliptin?

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

Answer 14

2 - B-blocker

• beta blockers block the symptoms of norepinephrine such as tachycardia, termors etc..

Question 15

Some drugs can raise blood glucose, such as prednisolone, thiazide and loop diuretics. What effect can this have on the efficacy of DPP-4 inhibitors, Sitagliptin and Linagliptin?

Answer 15

• dampens the efficacy
• drug is not as effective

Question 16

How are DPP-4 inhibitors, Sitagliptin and Linagliptin administered?

1 - MI
2 - SC
3 - oral
4 - IV

Answer 16

3 - oral

• can be taken with or without food

Question 17

What is the standard dose of the DPP-4 inhibitor Sitagliptin?

1 - 10mg
2 - 100mg
3 - 200mg
4 - 300mg

Answer 17

2 - 100mg

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