Asthma Core Drugs

Question 1

What is the primary mechanism of action of salbutamol?

Answer 1

Agonist at the β2 receptor on airway smooth muscle cells. Activation reduces Ca2+ entry and this prevents smooth muscle contraction

Question 2

What is the drug target of salbutamol?

Answer 2

Beta 2 (β2) adrenergic receptor

Question 3

What are the main side effects of salbutamol?

Answer 3

1. Palpitations/ agitation
2. Tachycardia/ Arrythmias
3. Hypokalaemia (at higher doses)

Question 4

How long action is salbutamol?

Answer 4

a short acting beta agonist (SABA). It’s half life is 2.5-5hours

Question 5

What is the selectivity of salbutamol to Beta 2 like?

Answer 5

Beta 2 selectivity is not absolute – as a result, cardiac (beta 1) effects can be seen

Question 6

How commonly prescribed are these drugs in the West London area in 2020?

Answer 6

1. Salbutamol: 12th
2. Fluticasone: 72nd
3. Mometasone: 62nd
4. Budesonide: 71st
5. Montelukast: 95th

Question 7

How can hypokalaemia happen with salbutamol?

Answer 7

• caused via an effect on sodium/ potassium ATPase

- effect can be exacerbated by coadministration with corticosteroids

Question 8

What is the primary mechanism of action of fluticasone?

Answer 8

1. Very powerful drugs
2. Multiple actions on many different cell types
3. Fluticasone directly decreases inflammatory cells such as eosinophils, monocytes, mast cells, macrophages, and dendritic cells
4. It reduces the number of these cells and also the number of cytokines they produce

Question 9

What is the drug target of fluticasone?

Answer 9

Glucocorticoid receptor

Question 10

What are the local side effects of fluticasone?

Answer 10

1. Sore throat
2. hoarse voice
3. opportunistic oral infections

Question 11

What are the systemic side effects of fluticasone?

Answer 11

1. Growth retardation in children
2. Hyperglycaemia
3. Decreased bone mineral density
4. Immunosuppression
5. Effects on mood
   (Many others)

Question 12

What receptor does fluticasone have a greater affinity for?

Answer 12

Greater affinity for the glucocorticoid receptor compared to cortisol.

Question 13

What is the oral bioavailability of fluticasone like?

Answer 13

• Oral bioavailability <1%

- Therefore, any systemic delivery via the inhaled route is predominantly through the pulmonary vasculature

Question 14

What the primary mechanism of action mometasone?

Answer 14

1. Very powerful drugs
2. Multiple actions on many different cell types
3. Mometasone directly decreases inflammatory cells such as eosinophils, monocytes, mast cells, macrophages, and dendritic cells
4. It reduces the number of these cells and also the number of cytokines they produce.

Question 15

What is the drug target of mometasone?

Answer 15

Glucocorticoid receptor

Question 16

What are the local side effects of mometasone?

Answer 16

1. Sore throat
2. hoarse voice
3. opportunistic oral infections

Question 17

What are the systemic side effects of mometasone?

Answer 17

1. Growth retardation in children
2. Hyperglycaemia
3. Decreased bone mineral density
4. Immunosuppression
5. Effects on mood
   (Many others)

Question 18

What receptor does mometasone have a greater affinity for?

Answer 18

Greater affinity for the glucocorticoid receptor compared to cortisol

Question 19

What is the oral bioavailability of mometasone like?

Answer 19

• Oral bioavailability <1%

- Therefore, any systemic delivery via the inhaled route is predominantly through the pulmonary vasculature.

Question 20

What is the primary mechanism of action of budesonide?

Answer 20

1. Very powerful drugs
2. Multiple actions on many different cell types
3. Budesonide directly decreases inflammatory cells such as eosinophils, monocytes, mast cells, macrophages, and dendritic cells
4. It reduces the number of these cells and also the number of cytokines they produce

Question 21

What is the drug target of budesonide?

Answer 21

Glucocorticoid receptor

Question 22

What are the local side effects of budesonide?

Answer 22

1. Hoarse voice

2. opportunistic oral infections

Question 23

What are the systemic side effects of budesonide?

Answer 23

1. Growth retardation in children
2. Hyperglycaemia
3. Decreased bone mineral density
4. Immunosuppression
5. Effects on mood
   (Many others)

Question 24

What is the oral bioavailability of budesonide like?

Answer 24

1. Oral bioavailability >10%

2. Therefore, inhaled budesonide will still result in some systemic absorption through the gastro-intestinal tract

Question 25

How potent is budesonide?

Answer 25

Less potent than fluticasone and mometasone

Question 26

What is the primary mechanism of action of montelukast?

Answer 26

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

Question 27

What is the drug target of montelukast?

Answer 27

CysLT1 leukotriene receptor

Question 28

What are the mild side effects of montelukast?

Answer 28

1. Diarrhoea
2. Fever
3. Headaches
4. Nausea or vomiting

Question 29

What are the serious side effects of montelukast?

Answer 29

1. Mood changes

2. Anaphylaxis

Question 30

When should montelukast be administered for prophylaxis of exercise-induced bronchoconstriction?

Answer 30

administered at least 2 hours before initiating exercise