Session 4 - Drugabetes Flashcards Preview

Semester 5 - Farmocology > Session 4 - Drugabetes > Flashcards

Flashcards in Session 4 - Drugabetes Deck (41)
1

What is a first line pharmacological treatment for diabetes?

Sulphonylureas (insulin release stimulants)

2

Give three examples of suphonylureas (include half lives and duration of action)

 Tolbutamide (t½ ~ 4hrs, duration of action 6-12hrs)
 Glibencamide (t½ ~ 10hrs, duration of action 18-24hrs)
 Glipizide (t½ ~ 7hrs, duration of action 16-24hrs)

3

What are indications for sulphonylureas

 Diabetes mellitus, in patients with residual β-cell activity

4

Give four contraindications for suphonylureas

 Breastfeeding women, elderly, renal and hepatic insufficiency

5

What is the mechanism of action of sulphonylureas

 Sulphonylureas antagonise β-cell K+/ATP activity, resulting in depolarisation. Voltage gated Ca2+ channels open, Ca2+ entry causes insulin vesicle fusion with cell membrane

6

What adverse reactions can sulphonylureas cause? (3)

 Hypoglycaemia
 GI disturbance
 Weight gain

7

What drug-drug interactions can sulphonylureas cause?

Highly protein bound

8

What's one of the most important second-line treatments for T2 diabetes?

Biguanides (metformin)

9

What are the indications for metformin?

 Type II diabetes – Endogenous insulin presence required

10

What are the contraindications for metformin?

 Compromised Kidney, lung and liver function

11

What is the mechanism of action for metformin?

 Unclear – Precise actions under current study
 Increases insulin receptor sensitivity, enhancing skeletal and adipose glucose uptake
 Inhibits hepatic gluconeogenesis
 Reduces hyperglycaemia, but does not induce hypoglycaemia

12

What 2 adverse drug rections for metformin?

 GI disturbances – ameliorated by slow dose titration
 Lactic Acidosis

13

Give another two other types of insulin sensitiser, other than biguanide?

`Thiazolidinediones
Meglitidines

14

Give two examples of Thiazolidinediones

 Rosiglitazone
 Pioglitazone

15

What are the indications for Thiazolidinediones

 Uncontrolled non insulin dependant diabetes

16

What is the mechanism of action for Thiazolidinediones

 PPAR-γ agonist. Agonistically bind to a nuclear hormone receptor site.
 Reduction in gluconeogenesis and an increased glucose uptake into muscles

17

What are the adversereactions to the glitazones? (2)

 GI disturbance
 Weight gain

18

What are the drug drug interactions of glitazones complicated by?

 Very heavily protein bound (~99%)

19

Give two examples of meglitidines

 Repaglinide
 Nateglinide

20

What are the indications for meglitidines

 Uncontrolled non insulin dependant diabetes

21

What is the mechanism of action for meglitidine?

 K+/ATP channel antagonists on β-cells, resulting in depolarisation, calcium entry and fusion of insulin containing vesicles with membrane

22

What concerning adverse drug reactions mean it is good to treat with meglitidines? (2)

 Relatively lower risk of hypoglycaemia than Sulphonylureas
 Not associated with weight gain – useful in treating obese patients

23

Name four different types of insulins

Ultra Rapid
Short Acting
Intermediate
Intermediate/Long Acting

24

What are indications for short acting/rapid insulins

Meals/Acute Hyperglycaemia

25

What are indications for intermediate/long acting insulins

Basal Insulin/Overnight control

26

Give two different insulin regimes

Pre-mixed inssulin
Intermediate/long acting insulin + Fast or short acting insulin

27

What is involved in a pre-mixed insulin regime?

Pre-mixed insulin is given twice a day, with morning and evening meals.

28

What is involved in an intermediate/long acting insulin + Fast or short acting insulin regime

Intermediate/long lasting insulin provides a basal level that extends overnight, fast or short acting insulin is injected with meals to provide an acute response. This gives a better level of glycaemic control.

29

What are indications for insulin treatment?

Insulin dependent diabetes mellitus

30

What is the mechanism of action of insulin?

Acts like endogenous insulin

31

Give three adverse drug reactions to insulin

 Local reactions
 Hypoglycaemia (coma) (overdose)
 Rarely, immune resistance

32

Outline the process of T2 diabetes treatment

o Begin with no pharmacological intervention, therapy starting with Diet, Exercise and Lifestyle changes
o A Biguanide (Metformin) started when necessary
o Over time if HbA1c levels go above 7%, a Sulphonylurea (e.g. Tolbutamide) is added to therapy
o Over time if HbA1c levels go about 7.5% a Thiazolidinedione (e.g. Rosiglitazone) may be added, or a newer hypoglycaemic, or start insulin therapy
o If on this regime if HbA1c levels go above 7.5%, doses will be titrated upwards to regain adequate glycaemic control

33

How is insulin dosing determined

Blood glucose monitoring several times a day

34

What is HbA1c?

Glucose in the blood will react with the terminal valine of the haemoglobin molecule to produce glycosylated haemoglobin (HbA1c). The percentage of HBA1c is a good indicator of how effective blood glucose control has been.
As RBCs normally spend ~3 months in the circulation the %HbA1c is related to the average blood glucose concentration over the preceding 2-3 months.
Poorly controlled diabetics can have a HbA1c value above 10%. In combination therapy, new medications are added at HbA1c values of 7 or 7.5% (see above).

35

Give three anti-obesity agents

Orlistat
Sibutramine
Rimonabant

36

What is the mechanism of action of Orlistat

 Gastric and pancreatic lipase inhibitor
 Reduces the conversion of up to 30% of dietary fat to fatty acids and glycerol

37

What is the mechanism of action of Sibutramine

 Noradrenaline and serotonin re-uptake inhibitor
 Appetite suppression, increased thermogenesis

38

What is the mechanism of action of Rimonabant

 Endocannabinoid antagonist

39

What are adverse drug reactions of Orlistat

 Broad GI disturbances
 (Soft fatty stools, flatus, faecal discharge/incontinence)

40

What are adverse drug reactions of sibutramine

 Increased heart rate and blood pressure

41

What are adverse drug reactions of rimonabant

 Depression – currently withdrawn in the UK by NICE