Asthma - Core Drugs

Question 1

List drugs used to treat asthma.

Answer 1

salbutamol, fluticasone, mometasone, budesonide, montelukast

Question 2

What is the drug target of salbutamol?

Answer 2

beta 2 adrenergic receptor

Question 3

Describe the mechanism of action of salbutamol.

Answer 3

agonist at receptor on airway smooth muscle cells > activation reduces Ca2+ entry > prevents muscle contraction

Question 4

Side effects of salbutamol

Answer 4

palpitations, agitation, tachycardia, arrythmias, hypokalaemia at higher doses

Question 5

Is salbutamol a SABA or LABA?

Answer 5

SABA (short acting)

Question 6

Half life of salbutamol

Answer 6

2.5-5 hours

Question 7

Why are cardiac effects possibly seen in those that take salbutamol?

Answer 7

the beta 2 selectivity is not absolute

Question 8

How does salbutamol cause hypokalaemia? This can be exacerbated by?

Answer 8

via an effect on sodium/ potassium ATPase > can be exacerbated by co-administration with corticosteroids

Question 9

Outline the mechanism of action of fluticasone.

Answer 9

directly decreases numbers of inflammatory cells and their cytokines eg eosinophils, monocytes, mast cells, macrophages, dendritic cells

Question 10

What is the drug target of fluticasone?

Answer 10

glucocorticoid receptor

Question 11

What are local side effects of fluticasone?

Answer 11

Sore throat, hoarse voice, opportunistic oral infections

Question 12

What are systemic side effects of fluticasone?

Answer 12

Growth retardation in children, hyperglycaemia, decreased bone mineral density, effects on mood, immunosuppression

Question 13

Does fluticasone have a greater or lesser affinity for the glucocorticoid receptor than cortisol?

Answer 13

greater affinity

Question 14

What is the oral bioavailability of fluticasone?

Answer 14

<1%

Question 15

Outline the mechanism of action of mometasone.

Answer 15

directly decreases numbers of inflammatory cells and their cytokines eg eosinophils, monocytes, mast cells, macrophages, dendritic cells

Question 16

What is the drug target of mometasone and budesonide?

Answer 16

glucocorticoid receptor

Question 17

Outline drug mechanism of action of budesonide.

Answer 17

directly decreases numbers of inflammatory cells and their cytokines eg eosinophils, monocytes, mast cells, macrophages, dendritic cells

Question 18

Oral bioavailability of budesonide?

Answer 18

> 10%

Question 19

Is budesonide more or less potent than mometasone and fluticasone?

Answer 19

less potent

Question 20

What is the drug target of montelukast?

Answer 20

CysLT1 leukotriene receptor

Question 21

Outline the mechanism of action of montelukast.

Answer 21

Antagonism of CysLT1 leukotriene receptor on eosinophils, mast cells, ASMC > decreases eosinophil migration, broncho-constriction and inflammation induced oedema

Question 22

Mild side effects of montelukast

Answer 22

Diarrhoea, fever, headaches, nausea or vomiting

Question 23

Serious side effects of montelukast

Answer 23

Mood changes, anaphylaxis

Question 24

For prophylaxis of exercise-induced bronchoconstriction, when should montelukast should be administered?

Answer 24

at least 2 hours before initiating exercise