Hypoglycaemics

Question 1

Metformin:

Undergoes liver metabolism

Answer 1

False. Metformin is not metabolised and is excreted unchanged in the urine. It is undetectable in plasma at 24 hours after a single dose.

Question 2

Metformin:

Is effective in overweight diabetics

Answer 2

True. It does not cause weight loss but decreases weight gain in combination with lifestyle modifications.

Question 3

Metformin:

Overdose can lead to lactic acidosis

Answer 3

True

Question 4

Metformin:

Has a half life of 6 hours

Answer 4

True. Peak concentrations are reached within one to three hours, but it’s duration of action is between 8 & 12 hours, and is therefore administered up to 3 times a day.

Question 5

Metformin:

Causes ketonuria

Answer 5

True

Question 6

Biguanides:

Stimulate pancreatic insulin secretion

Answer 6

False. Biguanide action involves decreased gluconeogenesis, increased glycolysis & decreased intestinal glucose reabsorption.

Question 7

Biguanides:

Are teratogenic

Answer 7

False. They are not recommended in pregnancy, though are not teratogenic.

Question 8

Biguanides:

Are used in all ages of diabetics

Answer 8

False. Ketonuria can occur in young diabetics treated with Insulin & Biguanides, and so Metformin is usually only used in adult onset diabetes.

Question 9

Biguanides:

Metformin has an oral bioavailability of 50-60%

Answer 9

True

Question 10

Biguanides:

Metformin is highly protein bound

Answer 10

False. Metformin has negligible protein binding.

Question 11

Sulphonylureas:

Are used in adult onset diabetes

Answer 11

True

Question 12

Sulphonylureas:

Can cause hypoglycaemia

Answer 12

True. Sulphonylureas, such as Gliclazide, unlike Metformin, can cause hypoglycaemic episodes and blood sugars must be checked regularly.

Question 13

Sulphonylureas:

Cause lactic acidosis in toxicity

Answer 13

False. Unlike Metformin, they do not cause lactic acidosis.

Question 14

Sulphonylureas:

Act by increasing insulin release

Answer 14

True. They also enhance Insulin’s effect of taking up glucose into muscle & fat. Other examples include glibenclamide, tolbutamide &, the older preparation, chlopropramide.

Question 15

Sulphonylureas:

Act by increasing insulin production

Answer 15

False. They act by increasing insulin release (not production) from the pancreatic beta cells, by binding to specific receptors.

Question 16

Sulphonylurea hypoglycaemics:

Tend to cause weight loss

Answer 16

False
They act by binding to a receptor coupled to increased Calcium entry into the pancreatic beta cells, which enhances Insulin secretion.

Question 17

Sulphonylurea hypoglycaemics:

Can be used to treat ketoacidosis

Answer 17

False. Oral hypoglycaemics have no role in the management of acute diabetic ketoacidosis.

Question 18

Sulphonylurea hypoglycaemics:

Are safe for use in pregnancy

Answer 18

False

Question 19

Sulphonylurea hypoglycaemics:

Are potentiated by Sulphonamides

Answer 19

True

Question 20

Sulphonylurea hypoglycaemics:

Have shorter half lives than Biguanides

Answer 20

False

Question 21

Sulphonylureas:

Have a hypoglycaemic effect potentiated by thiazide diuretics

Answer 21

False. Sulphonylureas’ hypoglycaemic effect is antagonised by thiazide diuretics.

Question 22

Sulphonylureas:

Are highly protein bound

Answer 22

True

Question 23

Sulphonylureas:

Displace bound Insulin from pancreatic islet 13 cells

Answer 23

True. Act by displacing bound Insulin from the pancreas &, therefore, they are only effective if endogenous insulin still exists (i.e. not absolute insulin loss/pancreatic beta cell destruction, as in type 1 DM).

Question 24

Sulphonylureas:

Include the drug Phenformin

Answer 24

False. Phenformin is a Biguanide similar to Metformin.

Question 25

Sulphonylureas: | Include the drugs Chlorpropramide & Metoclopramide

Answer 25

False. Despite the identical suffix (-pramide), Metoclopramide is a Benzamide anti-emetic.

Question 26

Sulphonylureas: | Are effective orally & parenterally

Answer 26

False. Sulphonylureas are only effective when administered orally. There is no IV preparation.

Question 27

Sulphonylureas: | Can cause pancytopenia

Answer 27

True. Tolbutamide & Chlorpropramide can cause leucopenia, agranulocytosis and thrombocytopenia in rare cases.

Question 28

Sulphonylureas: | Chlorpropramide is metabolised & excreted by the kidneys

Answer 28

False. Chlorpropramide undergoes no significant metabolism & is excreted, very slowly, largely unchanged in the urine.

Question 29

Sulphonylureas: | Gliclazide protects pancreatic beta cells from hyperglycaemic damage

Answer 29

True

Question 30

Sulphonylureas: | Gliclazide reduces atheromatous build up

Answer 30

True

Question 31

Insulin: | Neutral insulin has a pH of 7

Answer 31

True

Question 32

Insulin: | Different preparations exist lasting from less than 2 hrs to more than 36 hours

Answer 32

True

Question 33

Insulin: | 60 - 80% of insulin can be lost due to binding to the IV fluid container & tubing

Answer 33

True

Question 34

Insulin: | 80% of the secreted insulin is degraded by the liver & kidneys

Answer 34

True. The liver enzyme, hepatic glutathione transhydrogenase breaks the insulin molecule down into it's constituent peptide chains.

Question 35

Insulin: | Half life of endogenous insulin is 45 mins

Answer 35

False. Endogenous insulin has a very short half life of 10 - 20 mins and is fixed to many tissues, except RBCs & brain.

Question 36

Regarding insulin: | It's action involves a second messenger system

Answer 36

True | Insulin decreases cAMP in the liver

Question 37

Regarding insulin: | It is a polypeptide formed of 4 chains

Answer 37

False. It is formed of 2 chains, A and B.

Question 38

Regarding insulin: | It increases cAMP levels in the liver

Answer 38

False | Insulin decreases cAMP in the liver

Question 39

Regarding insulin: | Insulin increases potassium uptake into cells

Answer 39

True

Question 40

Regarding insulin: | Insulin increases protein synthesis in ribosomes

Answer 40

True It also inhibits hormone sensitive lipase, increases protein synthesis in ribosomes and increases glucose uptake in the peripheral tissues.

Question 41

Insulin facilitates glucose uptake into: | The pituitary

Answer 41

True

Question 42

Insulin facilitates glucose uptake into: | Red Blood Cells

Answer 42

False

Question 43

Insulin facilitates glucose uptake into: | Peripheral tissues inc. muscle & fat

Answer 43

True

Question 44

Insulin facilitates glucose uptake into: | Fibroblasts

Answer 44

True

Question 45

Insulin facilitates glucose uptake into: | Intestinal mucosa

Answer 45

False. It decreases reabsorption in the intestine, which can lead to glycosuria.

Question 46

Insulin secretion: | Can be blocked by Atropine

Answer 46

True | whereas the anticholinergics, including Atropine, can block it's release.

Question 47

Insulin secretion: | Is inhibited by the hormone Somatostatin

Answer 47

True

Question 48

Insulin secretion: | Is inhibited by the phosphodiesterase inhibitor Theophylline

Answer 48

False. Theophylline stimulates Insulin secretion but Somatostatin opposes it's secretion.

Question 49

Insulin secretion: | Is stimulated by leucine

Answer 49

True

Question 50

Insulin secretion: | Is increased by Beta 2 adrenergic receptor activation

Answer 50

True. The Sympathetic nervous system has conflicting effects on Insulin release, Alpha 2 agonists decrease Insulin release, whilst Beta 2 agonists increase it's secretion.