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Flashcards in Oral Hypoglycaemic Agents Deck (37):
1

Chronic disturbed carbohydrate and lipid metabolism results from

absolute and relative lack of insulin

2

What is meant by 'relative' lack of insulin?

Insulin is present but doesn't work as effectively (resistance)

3

T/F Insulin levels are always abnormal in T2D

False; early stages insulin levels can be normal or slightly elevated; they fall as the disease progresses

4

Early in T2D, insulin levels are __________ or _________; as the disease progresses, insulin levels __________ and can resemble T1D

normal, slightly elevated; decrease

5

What causes insulin resistance?

decreased numbers and/or impaired function of insulin receptors

6

Pharmacotherapy in T2D needs to target

impaired secretion of insulin and receptor responsiveness (dysfunctional)

7

How do sulphonylureas (oral hypoglycaemics) stimulate insulin release?

Inhibit ATP-sensitive K+ channel (normally hyperpolarizes B cell, powered by ATP from glucose metabolism in mitochondria) causing depolarization and Ca2+ influx that triggers exocytotic release of insulin

8

Sulfonylureas

chlorpropramide, glibenclamide, glipizide

9

What is the action of sulfonylureas?

Increase in insulin secretion from B cells by inhibiting Katp channels - restores phase 1 insulin secretion

10

What are the adverse effects of sulfonylureas?

hypoglycaemia and weight gain; cross BBB so can't be used in pregnancy; nephropathy needs to be monitored bc excreted by kidney

11

What type of receptor is the insulin cell surface receptor?

Tyrosine kinase

12

What is the action of the insulin receptor?

Insulin binds the tyrosine kinase receptor that switch on protein and glycogen synthesis, glucose transport, and translocation of the GLUT4 transporter to cell surfaces to take up glucose for metabolic pathways

13

Metformin is what class of drug?

Biguanide

14

What are the actions of metformin for tx in T2D?

increase insulin-mediated peripheral glucose uptake; reduce hepatic glucose production; decrease carbohydrate absorption; reduce LDL and TAG levels

15

What is the mechanism of metformin?

Activation of AMP kinase

16

What are the adverse effects of metformin?

GI disturbances: diarrhoea, nausea, abdominal discomfort, anorexia; lactic acidosis; weight loss; contraindicated in impaired renal function

17

In treatment of T2D, sulfonylureas target

insulin secretion - stimulate secretion from pancreas to restore phase 1 insulin spike

18

In treatment of T2D, biguanides (metformin) target

insulin resistance - sensitize the body to insulin and/or control hepatic glucose production

19

Acarbose

alpha-glucosidase inhibitors

20

What is the mechanism of alpha-glucosidase inhibitors?

block the enzymes that digest and promote absorption of starches in the SI

21

What are the adverse effects of alpha-glucosidase inhibitors?

flatulence, abdo discomfort, loose stools, abdo pain, contraindicated in IBD or cirrhosis

22

In tx of T2D, alpha-glucosidase inhibitors target

glucose absorption

23

Incretins target

insulin secretion and glucagon secretion

24

Incretins __________ insulin and _________ glucagon

increase; decrease

25

Dipeptidyl peptidase-4 inhibitors target

DPP4 which breaks down GLP-1

26

What is the action of DPP4 inibitors?

Increase GLP-1 levels which increase insulin and decrease glucagon

27

Sitagliptin

DPP4 inhibitor

28

What are the adverse effects of DPP4 inhibitors?

URT infections; headaches; hypoglycaemia in combo with insulin; allergic/hypersensitivity reactions; pancreatitis

29

Exenatide

GLP-1 receptor agonist

30

How is exenatide administered?

subcutaneous injection

31

What are the actions of exenatide?

potentiate glucose-mediated insulin secretion (GLP-1 action); suppress glucagon release; slow gastric emptying; decrease appetite

32

What are the adverse effects of exenatide (GLP-1R agonist)?

Nausea, vomiting, diarrhoea; weight loss; Ab formation, immune reactions, pancreatitis; endocrine neoplasias

33

In the tx of T2D, incretins, incretin mimetics and enhancers target

incretins - GLP-1, GIP; increase insulin and decrease glucagon

34

In the tx of T2D, SGLT2 inhibitors target

sodium glucose cotransporter 2 to slow renal glucose reabsorption

35

What is the treatment progression in T2D?

diagnosis; therapeutic lifestyle change; monotherapy (metformin); combo therapy - oral only (until renal effects; also SC exenatide soon); combo therapy - oral with insulin

36

Target glucose homeostasis in diabetes treatment are

4-8mmol/L

37

Target HbA1c levels in diabetes treatment are

6%