Drugs Used in Obesity Flashcards Preview

MD1 Metabolism > Drugs Used in Obesity > Flashcards

Flashcards in Drugs Used in Obesity Deck (36):
1

What are the limitations of body mass index (BMI)?

Doesn't take lean muscle mass into account
Age/gender/ethnicity differences

2

What are the weight classifications of BMI?

Underweight 30
Morbid obese >40

3

What are some factors contributing to the increasing incidence of obesity?

Susceptibility genes
Decline in physical activity
Eat more
Energy dense food
Sleep deprivation
Cultural and SE status

4

What causes obesity to be the second most common cause of preventable death?

Co-morbidities

5

What are the co-morbidities of obesity?

Diabetes
Sleep apnoea
Osteoarthritis
Cancer
Non-alcoholic fatty liver disease
Coronary heart disease
Hypertension

6

What are the long-term mechanisms for control of appetite?

Adiposity signals
- Insulin
- Leptin

7

How does leptin affect appetite?

Accesses hypothalamus
Changes expression and release of various neuropeptides

8

What are the short-term mechanisms for control of appetite?

Satiety signals
- Nerve input
- CCK
- Other hormones and neurohormones

9

Where is short-term satiety regulated in the brain?

Medulla

10

Which hormone increases hunger and how?

Ghrelin released from stomach when its empty > goes to medulla > hunger

11

What does it mean for drug therapy design since it's a complex system of peptides that regulates food intake?

Need cocktail of drugs with multiple targets for successful treatment

12

Which cells predominantly secrete leptin?

Fat cells

13

What are plasma levels of leptin proportional to?

BMI
Fat

14

Where are the receptors for leptin located?

Hypothalamus

15

Are leptin defects relevant to human obesity?

Only in very small number of patients

16

Why may leptin insensitivity develop in obesity?

Trouble crossing BBB
Down-regulation of leptin receptors

17

What do beta3-adrenergi receptor agonists do?

Increase thermogenesis > increase energy expenditure

18

What do all obesity treating drugs need to be combined with?

Very low calorie diet
Increased exercise

19

What is phentermine?

Amphetamine derivative that increase noradrenaline availability to bind to receptors
Suppresses appetite

20

How is phentermine used?

BMI >30
Only useful in short-term
- Usually for 4-6 weeks
- Up to 12 weeks

21

How does phentermine work?

Competes with noradrenaline for neuronal re-uptake receptors > taken up
Displaces noradrenaline from vesicles
Increased noradrenaline intracellularly > Ca-independent release
More noradrenaline binds to post-synaptic receptors

22

What are the adverse effects of phentermine?

Increased BP and HR
Insomnia
Nervousness
Headache
Dry mouth

23

Does tolerance and dependenc develop to phentermine?

Some dependence
Tolerance, yes > why used in short term

24

What are the contra-indications for phentermine?

Other weight loss dugs
MAO inhibitors
Pregnancy

25

What is orlistat?

Gastric and pancreatic lipase inhibitor
Decreases dietary fat absorption

26

When is orlistat used?

BMI >30

27

How does orlistat work?

Covalently binds to lipases in gut to inhibit their activity

28

What does orlistat reduce?

Body weight
Waist circumference
Blood glucose
Insulin
Dyslipidaemia
Blood pressure

29

What are the adverse effects of orlistat?

Mainly GI > controlled if adhere to low fat diet
- Explosive diarrhoea
- Faecal fat leakage

30

What must orlistat be combined with?

Low fat diet
Vitamin E and D supplementation

31

What is liraglutide?

Glucagon-like peptide-1 (GLP-1) receptor agonist

32

What are the adverse effects of liraglutide?

Nausea
Diarrhoea
Rare: pancreatitis

33

What are the actions of GLP-1 agonists?

Increase
- Neuroprotection
- Insulin
- Insulin biosynthesis
- Glucose uptake and storag
Decrease
- Appetite
- Gastric emptying
- Glucagon secretion
- Glucose production

34

What is topiramate?

Used for epilepsy and migraine
Off-label use for weight loss

35

What does topimarate do?

Energy expenditure
Appetite suppression

36

What are the adverse effects of topimarate?

Dizziness
Taste alteration
Teratogenic