Insulin Drugs

Question 1

What are the glucose values for various conditions?

Answer 1

Hypoglycaemia- 10mmol.

Question 2

What is the homeostasis of hyperglycaemia?

Answer 2

Endogenous glucose production leads to hypoglycaemia. Insulin is released from beta pancreatic cells. Acts upon the liver, muscle, adipocytes. Blood glucose rises.

Question 3

Explain the mechanisms of glucose stimulated insulin release.

Answer 3

Food intake leads to digestion. Causes glucose uptake by beta cells. The uptake of glucose stimulate the blocking of kATP channels. This depolarises the cell causing a calcium influx. Insulin is released, lowering blood glucose.
Drugs that block-K channels mimic the actions of glucose, thus stimulated the secretion of insulin. These are called insulin secretagogues and are used to treat type two diabetes.
Drugs that open K-channels inhibit the actions and block glucose thus stimulating glucagon release. Used as hypoglycaemic drug treatments

Question 4

Explain glucose homeostasis integration with digestion.

Answer 4

Food intake leads to digestion. This causes the release of gut hormones leading to a rise in GLP-1. This activates GLP2 receptors causing insulin release.

Question 5

Explain short duration insulin therapy for hyperglycaemia.

Answer 5

Soluble rapid acting human insulin.
Effects can be seen after 30 minutes and last 2-4 hours.
Injected before, with, or after food.

Question 6

Give examples of short acting insulin therapy.

Answer 6

Insulin aspart
Insulin lispro
Insulin glulisine.

Question 7

Explain intermediate/longer acting insulin therapy.

Answer 7

The onset is about 1-2 hours and their peak action lasts 4-12 hours.

Question 8

List examples of intermediate/longer acting insulin therapy.

Answer 8

Insulin determir, insulin glargine, insulin zinc suppression, isophane insulin, protamine zinc insulin.
Insulin isoprene can be porcine, human or bovine.

Question 9

Explain biphasic insulin preparations.

Answer 9

Mixture of intermediate and fast acting.

Early onset mixed with long lasting actions.

Question 10

Given examples of biphasic insulin preparations.

Answer 10

Biphasic insulin aspart
Biphasic insulin lispro
Bisphasic isophane insulin

Question 11

Explain glucagon therapy.

Answer 11

Hyperglycaemia inducing therapy used to treat hypoglycaemia.
First-aid treatment when oral glucose is insufficient.
Common side effects include nausea and headaches
Increased levels of glucagon promotes glycogenolysis (glycogen to glucose, gluconeogenesis and lipolysis.

Question 12

What are sulphonylurea?

Answer 12

kATP channel inhibitors- insulin secretagogues.
Administered orally.
High risk of hypoglycaemia.

Question 13

What are short acting sulphonyreas

Answer 13

Gliclazine and tolbutamide.

Question 14

What are long acting sulphonylureas?

Answer 14

Chlorproamine.
Glibenclamine
Glimepridine

Question 15

What are meglitinides?

Answer 15

kATP antagonists- insulin secretagoues.
Prandial glucose relators.
A decreased risk of hypoglycaemia compared to sulphonylureas- therefore preferred.

Question 16

What are examples of meglitinides

Answer 16

Repaglinide and Nateglinide

Question 17

Why can’t GLP-1 be used as a secretagogue?

Answer 17

Because it has a very short half life and is rapidly broken down by DDP-4.

Question 18

Explain Incretin mimemtics.

Answer 18

Boost insulin release by enhancing the normal physiology of incretin-mediated insulin release.
Peptide agonists of GLP-1 however are not broken down by DDP-4.
Much reduced risk of hypoglycaemia compared to sulphonylureas.

Question 19

What are examples of incretin mimemtics?

Answer 19

Exenatide and Liraglutide.

Question 20

Explain DPP-4 inhibitors.

Answer 20

Incretin Mimemics

Raise the half life of serum GLP-1, increasing its effects.

Question 21

Give examples of DPP-4 inhibitors.

Answer 21

Stiagliptin.

Vildagliptin

Question 22

What are insulin sensitisers?

Answer 22

Improve sensitivity of a target organ to insulin.

E.g Biguanides and Thiazolidiendoines.

Question 23

Explain biguanidies.

Answer 23

A form of insulin sensitiser, activates enzymes.
Prevents hepatic production of glucose and overcomes insulin resistance by improving insulin sensitivity.
E.g metformin. Most widely used anti-diabetic drug- drug of choice for people with heart failure.

Question 24

Explain thiuazolidiendiones.

Answer 24

Insulin sensitizer.
Target adipocytes.
Activate PPARy- the protein involved in the transcription of insulin-sensitive genes that regulate glucose and fat metabolism.

Question 25

List some examples of thiazolidiendiones.

Answer 25

Glitazone and pioglitazone.

Question 26

Explain alpha glucosidase inhibitors.

Answer 26

Prevent oligosaccharides being converted into glucose by a-glucosidase.
Absorption of starchy foods is slowed, raising blood glucose after a meal.
Example is acarbose.

Question 27

Explain SGLT2 inhibitors.

Answer 27

SGLT2 stands for sodium-coupled glucose transported.

SGLT2 inhibitors causes excess glucose to be eliminated in urine, reducing hyperglycaemia.

Question 28

What are the advantages of SGLT2 inhibitors?

Answer 28

Weight loss, insulin independent, low risk of hypo, reduces hypertension.

Question 29

What are examples of SGLT2 inhibitors?

Answer 29

Dapagliflozin
Canagliflozin
Empagliflozin