Asthma Flashcards
Name the fast onset b agonist drugs, which ones are short duration and which are long duration?
Inhaled terbutaline and inhaled salbutamol - short duration
Inhaled formoterol - long duration
Name the slow onset b agonists, which are short duration and which are long duration?
Oral salbutamol - short duration
Inhaled salmeterol, oral bambuterol - long duration
What are the main ADRs of b agonists?
Skeletal muscle tremor (b2 activity)
Tachycardia, palpitations and dysthymia (b1 activity)
What is the main DDI concerning b agonists?
b antagonists - bind to both b1 and b2 receptors which could be dangerous for severe asthma
Describe the pharmacokinetics of b agonists
Inhalation as aerosol, powder/nebulised/IV
90% deposited in upper airway/swallowed
How are the oropharyngeal effects of corticosteroids reduced?
By using a spacer (slows down aerosol entry)
Name 2 methylxanthine drugs and how they are thought to work
Theophylline, aminophylline - thought to antagonise adenosine receptors
What are the main ADRs of methylxanthines?
Psychomotor agitation
Tachycardia
NARROW THERAPEUTIC WINDOW
Name 2 anticholinergics and explain how they work
Ipratroprium and tiotropium
Used in COPD, additionally for b agonists, where b agonists are contraindicated e.g. IHD
Binds to and block M3 receptors preventing bronchoconstriction and inhibiting mucus secretion
What is the main contraindications for b agonists?
IHD
What other class of drugs can be used as add on therapies in addition to b agonists and corticosteroids?
Methylxanthines
Anticholinergics
Leukotrine receptor antagonists
What are the 5 steps of asthma management?
1 - inhaled short acting b agonist reliever therapy (as and when needed) e.g. Salbutamol
If using b agonist 3 x per week or waking in the night once a week:
2 - addition of inhaled corticosteroid (twice daily and titrate to lowest dose when controlled) e.g. Budesonide
3 - addition of long acting b agonist e.g. Salmeterol
4 - increase corticosteroid/ addition of leukotrine receptor agonist/anticholinergic/methylxanthine/oral b2 agonist
5 - addition of oral corticosteroid/anti IgE therapy
What non-pharmacological measures can be taken in the management of asthma?
Avoid trigger
Check inhaler technique
How would you manage acute severe asthma?
In ITU: oxygen (intubate), nebulised salbutamol, nebulised ipratropium, prednisolone oral tablet/hydrocortisone IV, magnesium sulphide
What is the optimum size of particles in aerosol?
1-5 microns
