Pharma - Asthma Flashcards
List 5 drugs that can treat asthma.
→ Salbutamol → Fluticasone → Mometasone → Budesonide → Montelukast
What is the primary mechanism of action for salbutamol?
→ Agonist at the β2 receptor on airway smooth muscle cells
→ Activation reduces Ca2+ entry and this prevents smooth muscle contraction.
What is the drug target for salbutamol?
Beta 2 (β2) adrenergic receptor
What are the main side effects of salbutamol?
→ Palpitations/ agitation
→ Tachycardia/ Arrythmias
→ Hypokalaemia (at higher doses)
What type of drug is Salbutamol? What’s its half life?
→ Salbutamol is a short acting beta agonist (SABA).
→ It’s half life is 2.5-5hours
Why can salbutamol have effects on the heart?
→ Beta 2 selectivity is not absolute
→ as a result, cardiac (beta 1) effects can be seen.
Why can salbutamol cause hypokalaemia?
caused via an effect on sodium/ potassium ATPase
How is the salbutamol effect on hypokalaemia exacerbated?
co-administration with corticosteroids
What is the primary mechanism of action for Fluticasone / Mometasone?
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
What is the drug target of Fluticasone / Mometasone?
Glucocorticoid receptor
What are the side effects of Fluticasone / Mometasone?
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
Which one has greater affinity for a glucocorticoid receptor? Fluticasone / Mometasone or Cortisol?
Fluticasone + Mometasone
What is the predominant method of delivery for Fluticasone / Mometasone? Why?
→ inhaled route
→ predominately through the pulmonary vasculature
→ oral bioavailability <1%
What is the mechanism of action of Budesonide?
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
What is the drug target for Budesonide?
Glucocorticoid receptor
What are the main side effects of Budesonide?
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
How potent is Budesonide in comparison to Fluticasone or Mometasone?
→ Less potent than fluticasone and mometasone
→ Oral bioavailability >10%.
→ Therefore, inhaled budesonide will still result in some systemic absorption through the gastro-intestinal tract
What is the primary mechanism of action for Montelukast?
Antagonism of CysLT1 leukotriene receptor on → eosinophils → mast cells → airway smooth muscle cells decreases: → eosinophil migration → broncho-constriction → inflammation induced oedema
What is the drug target of Montelukast?
CysLT1 leukotriene receptor
What are the main side effects of Montelukast?
Mild side effects: → Diarrhoea → Fever → Headaches → Nausea or vomiting
Serious side effects:
→ Mood changes
→ Anaphylaxis
When should Montelukast be taken before exercise?
administered at least 2 hours before initiating exercise.
Why is Montelukast taken before exercise?
For prophylaxis of exercise-induced bronchoconstriction
