Pharmacology Of Asthma Flashcards
Salbutamol mechanism of action
Agonist at the β2 receptor on airway smooth muscle cells. Activation reduces Ca2+ entry and this prevents smooth muscle contraction.
Drug target of salbutamol
Beta 2 adrenergic receptor
Side effects of salbutamol
Palpitations/ agitation
Tachycardia/ Arrythmias
Hypokalaemia (at higher doses)
Extra info on salbutamol
Salbutamol is a short acting beta agonist (SABA). It’s half life is 2.5-5hours.
Beta 2 selectivity is not absolute – as a result, cardiac (beta 1) effects can be seen.
Hypokalaemia can be caused via an effect on sodium/ potassium ATPase. This effect can be exacerbated by coadministration with corticosteroids
In 2020, salbutamol was the 12th most commonly prescribed drug in the West London area
Fluticasone mechanism
Very powerful drugs. Multiple actions on many different cell types. Fluticasone directly decreases inflammatory cells such as eosinophils, monocytes, mast cells, macrophages, and dendritic cells. It reduces the number of these cells and also the number of cytokines they produce.
Fluticasone drug target
Glucocorticoid receptor
Fluticasone side effect
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
(Many others)
Fluticasone extra info
Greater affinity for the glucocorticoid receptor compared to cortisol.
Oral bioavailability <1%. Therefore, any systemic delivery via the inhaled route is predominantly through the pulmonary vasculature.
In 2020, fluticasone was the 72nd most commonly prescribed drug in the West London area
Mometasone mechanism of action
Very powerful drugs. Multiple actions on many different cell types. Mometasone directly decreases inflammatory cells such as eosinophils, monocytes, mast cells, macrophages, and dendritic cells. It reduces the number of these cells and also the number of cytokines they produce.
Mometasone target
Glucocorticoid receptor
Mometasone side effects
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
(Many others)
Mometasone extra info
Greater affinity for the glucocorticoid receptor compared to cortisol.
Oral bioavailability <1%. Therefore, any systemic delivery via the inhaled route is predominantly through the pulmonary vasculature.
In 2020, mometasone was the 62nd most commonly prescribed drug in the West London area
Budesonide mechanism of action
Budesonide Very powerful drugs. Multiple actions on many different cell types. Budesonide directly decreases inflammatory cells such as eosinophils, monocytes, mast cells, macrophages, and dendritic cells. It reduces the number of these cells and also the number of cytokines they produce.
Budesonide drug target
Glucocorticoids receptor
Budesonide side effect
Local side effects:
Hoarse voice, opportunistic oral infections
Systemic side effects:
Growth retardation in children
Hyperglycaemia
Decreased bone mineral density
Immunosuppression
Effects on mood
(Many others)
Extra info on Budesonide
Oral bioavailability >10%. Therefore, inhaled budesonide will still result in some systemic absorption through the gastro-intestinal tract.
Less potent than fluticasone and mometasone
In 2020, budesonide was the 71st most commonly prescribed drug in the West London area
Montelukast mechanism of action
Antagonism of CysLT1 leukotriene receptor on eosinophils, mast cells and airway smooth muscle cells decreases eosinophil migration, broncho-constriction and inflammation induced oedema
Montelukast target
CysLT1 leukotriene receptor
Side effects of Montelukast
Mild side effects:
Diarrhoea
Fever
Headaches
Nausea or vomiting
Serious side effects:
Mood changes
Anaphylaxis
Extra info of Montelukast
For prophylaxis of exercise-induced bronchoconstriction, montelukast should be administered at least 2 hours before initiating exercise.
In 2020, montelukast was the 95th most commonly prescribed drug in the West London area
Main bronchodilator
Salbutamol and leukotriene RA (montelukast)
Anti inflammatory
Corticosteroids
Fluticasone
Mometasone
Budesonide
Montelukast
