Pharma - Asthma

Question 1

List 5 drugs that can treat asthma.

Answer 1

→ Salbutamol
→ Fluticasone
→ Mometasone
→ Budesonide
→ Montelukast

Question 2

What is the primary mechanism of action for salbutamol?

Answer 2

→ Agonist at the β2 receptor on airway smooth muscle cells

→ Activation reduces Ca2+ entry and this prevents smooth muscle contraction.

Question 3

What is the drug target for salbutamol?

Answer 3

Beta 2 (β2) adrenergic receptor

Question 4

What are the main side effects of salbutamol?

Answer 4

→ Palpitations/ agitation
→ Tachycardia/ Arrythmias
→ Hypokalaemia (at higher doses)

Question 5

What type of drug is Salbutamol? What’s its half life?

Answer 5

→ Salbutamol is a short acting beta agonist (SABA).

→ It’s half life is 2.5-5hours

Question 6

Why can salbutamol have effects on the heart?

Answer 6

→ Beta 2 selectivity is not absolute

→ as a result, cardiac (beta 1) effects can be seen.

Question 7

Why can salbutamol cause hypokalaemia?

Answer 7

caused via an effect on sodium/ potassium ATPase

Question 8

How is the salbutamol effect on hypokalaemia exacerbated?

Answer 8

co-administration with corticosteroids

Question 9

What is the primary mechanism of action for Fluticasone / Mometasone?

Answer 9

directly decreases inflammatory cells such as:
→ eosinophils
→ monocytes
→ mast cells
→ macrophages
→ dendritic cells
reduces the number of these cells + also number of cytokines they produce

Question 10

What is the drug target of Fluticasone / Mometasone?

Answer 10

Glucocorticoid receptor

Question 11

What are the side effects of Fluticasone / Mometasone?

Answer 11

local side effects:
→ Sore throat
→ hoarse voice
→ opportunistic oral infections

systemic side effects:
→ Growth retardation in children
→ Hyperglycaemia
→ Decreased bone mineral density
→ Immunosuppression
→ Effects on mood, etc

Question 12

Which one has greater affinity for a glucocorticoid receptor? Fluticasone / Mometasone or Cortisol?

Answer 12

Fluticasone + Mometasone

Question 13

What is the predominant method of delivery for Fluticasone / Mometasone? Why?

Answer 13

→ inhaled route
→ predominately through the pulmonary vasculature
→ oral bioavailability <1%

Question 14

What is the mechanism of action of Budesonide?

Answer 14

directly decreases inflammatory cells such as:
→ eosinophils
→ monocytes
→ mast cells
→ macrophages
→ dendritic cells
reduces the number of these cells + also number of cytokines they produce

Question 15

What is the drug target for Budesonide?

Answer 15

Glucocorticoid receptor

Question 16

What are the main side effects of Budesonide?

Answer 16

local side effects:
→ hoarse voice
→ opportunistic oral infections

systemic side effects:
→ Growth retardation in children
→ Hyperglycaemia
→ Decreased bone mineral density
→ Immunosuppression
→ Effects on mood, etc

Question 17

How potent is Budesonide in comparison to Fluticasone or Mometasone?

Answer 17

→ Less potent than fluticasone and mometasone
→ Oral bioavailability >10%.
→ Therefore, inhaled budesonide will still result in some systemic absorption through the gastro-intestinal tract

Question 18

What is the primary mechanism of action for Montelukast?

Answer 18

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

Question 19

What is the drug target of Montelukast?

Answer 19

CysLT1 leukotriene receptor

Question 20

What are the main side effects of Montelukast?

Answer 20

Mild side effects:
→ Diarrhoea
→ Fever
→ Headaches
→ Nausea or vomiting

Serious side effects:
→ Mood changes
→ Anaphylaxis

Question 21

When should Montelukast be taken before exercise?

Answer 21

administered at least 2 hours before initiating exercise.

Question 22

Why is Montelukast taken before exercise?

Answer 22

For prophylaxis of exercise-induced bronchoconstriction