5. Pharmacology of Insulin

Question 1

What is the role of insulin?

Answer 1

Stimulates uptake of glucose into liver, muscle and adipose tissue; decreases hepatic glucose output via inhibition of gluconeogenesis; inhibits glycogenolysis, promotes uptake of fats.

Question 2

What are the different types of insulin available?

Answer 2

Animal porcine and bovine, recombinant DNA technology - human short acting, human rapid acting insulin analogues, isophane intermediate acting insulin, long acting basal analogue insulins, very long acting basal analogue insulins.

Question 3

How is genetic engineering used to produce insulin?

Answer 3

Take plasmid out of bacterium, cut plasmid using enzymes and insert human insulin gene, insert plasmid into new bacterium, bacterium divides and begins producing insulin.

Question 4

What are the six main categories of insulin?

Answer 4

Ultrafast acting, rapid acting, short acting, intermediate acting, long acting, very long acting.

Question 5

Give an example of an ultrafast acting insulin.

Answer 5

FiAsp.

Question 6

Give examples of rapid acting insulin.

Answer 6

Humalog, novorapid, apidra.

Question 7

What is the onset time of rapid acting insulin and therefore when should it be given?

Answer 7

5-15 minutes so inject just before eating.

Question 8

Give examples of short acting insulin.

Answer 8

Actrapid, humulin S, hypurin bovine and porcine neutral.

Question 9

What is the onset time of short acting insulin and therefore when should it be administered?

Answer 9

30-60 minutes so inject at least 15-30 mins before eating.

Question 10

Give examples of intermediate acting insulin.

Answer 10

Insulatard, humulin I, insuman basal, hypurin bovine, porcine, isophane.

Question 11

What is the onset time of intermediate acting insulin?

Answer 11

2-4 hours.

Question 12

Why may snacking before bed be needed with intermediate acting insulin use?

Answer 12

It peaks 4-8 hours after administration, so snacking avoids hypoglycaemia when it peaks in early hours of the morning.

Question 13

Give examples of long and very long acting insulin.

Answer 13

Glargine, detemir, degludec.

Question 14

What is the onset and duration of long and very long acting insulin?

Answer 14

2-6 hours onset, lasts 24 hours if long or 50+ hours if very long.

Question 15

What are some of the ADRs of insulin?

Answer 15

Hypoglycaemia, hyperglycaemia (if not enough given), lipodystrophy (hypertrophy or atrophy from anabolic effects), painful injections, allergies.