Insulin

Question 1

What are common indications for insulin therapy?

Answer 1

• Type 1 and type 2 diabetes
• DKA
• HHS
• Hyperkalaemia

Question 2

What is the mechanism of action of insulin?

Answer 2

1. Increases glucose uptake by insulin-sensitive tissues (e.g. adipose, muscle)
2. Increases glycogen synthesis in muscle and liver
3. Increases amino acid uptake into muscle
4. Increases protein synthesis
5. Increases triacylglycerol synthesis in adipocytes and liver i.e. stimulates lipogenesis and inhibits lipolysis
6. Inhibits the enzymes of gluconeogenesis in the liver
7. Promotes K+ ion entry into cells

Question 3

What are examples rapid acting insulins?

Answer 3

• Novorapid
• Apidra
• Humalog

Question 4

When are do you need to be cautious with insulins?

Answer 4

• Renal impairment
• Hepatic impairment
• Pregnancy and breastfeeding

Question 5

What are examples of intermediate acting Insulins?

Answer 5

• Novomix 30
• Humalog Mix25
• Humulin I
• Insulatard

Question 6

What are examples of long acting insulins?

Answer 6

• Lantus
• Levemir

Question 7

What are examples of short-acting insulins?

Answer 7

• Actrapid
• Humulin S

Question 8

When is the peak effect of novorapid?

Answer 8

Within 10-20 minutes of administration

Question 9

When is the peak effect of humalog?

Answer 9

15 minutes of administration

Question 10

When is the peak effect of actrapid?

Answer 10

2-4 hours

Question 11

When is the peak effect of humulin S?

Answer 11

30 minutes to 2.5 hours

Question 12

When is the peak effect of insulatard?

Answer 12

45 mins - 12 hours

Question 13

When is the peak action of Humulin I?

Answer 13

45 mins - 8 hours

Question 14

When is the peak effect of humulin mix 25?

Answer 14

20 minutes - 2.5 hours

Question 15

What type of insulin are novorapid 30 and humilin mix25?

Answer 15

Biphasic insulin - rapid + intermediate acting

Question 16

When should analogue mixtures be administered?

Answer 16

Just before/during/after food

Question 17

When should rapid acting insulins be administered?

Answer 17

Just before/during/after meals

Question 18

When should short acting insulins be administered?

Answer 18

20-45 mins before food

Question 19

When should long-acting insulins be administered?

Answer 19

Once/Twice a day, at the same time every day

Question 20

What is a three times daily regimen?

Answer 20

Mix of short and intermediate acting before breakfast, short acting before lunch, and intermediate at bedtime

Question 21

What is a basal bolus regimen?

Answer 21

Long acting mix once daily with short acting insulin before meals

Question 22

What is a twice daily regimen?

Answer 22

Mix of short and intermediate acting given before breakfast and tea

Question 23

What insulins are used in a twice daily regimen?

Answer 23

Premixed e.g. Novomix 30 or Humalog mix25

Question 24

What is the normal daily requirement of insulin?

Answer 24

30-50 units - varies substantially between individuals

Question 25

How is insulin given in diabetic emergencies?

Answer 25

50 units of actrapid diluted in 50 ml 0.9% saline - 1unit/ml

Question 26

How would youa administer insulin in hyperkalaemia?

Answer 26

10 units Actrapid added to 20% glucose 100mls and infused of 15 minutes

Question 27

What are adverse side effects of insulin therapy?

Answer 27

Hypoglycaemia

Injection site

• Lipodystrophy
• Rashes
• Transient oedema

Question 28

How is insulin cleared?

Answer 28

Kidneys

Question 29

If insulin is given as an infusion, what should you monitor?

Answer 29

K+ at least every 4 hours

Question 30

Why should you avoid giving actrapid to treat unexpected high blood glucose concentration?

Answer 30

Time to peak effect (2-3 hours) is longer than commonly appreciated, and trying to correct hyperglycaemia quickly is often unnecessary and can be dangerous. Instead, try to understand why hyperglycaemia has occured, and make small alterations to regimen