6.2: Asthma Pharmacology Flashcards
(23 cards)
Asthma is characterised by infiltration of which T cells?
Th2 cells
What are 2 examples of long acting beta agonists?
Salmeterol
Formoterol
Which drugs are in a Symbicort inhaler?
Budenoside (steroid)
Formoterol (LABA)
What is the pathophysiology of asthma in the bronchi?
1) bronchial smooth muscle contraction, due to stimuli
2) mucosal swelling caused by mast cell and basophils degranulation
3) increased mucus production that can cause mucus plugging
What is the first step is treating mild intermittent asthma?
SABA inhaler PRN
How does a SABA for asthma work?
Works on beta 2 receptors to reverse bronchoconstriction (activates Gas -> adenylyl cyclise -> cAMP -> PKA)
What are 2 examples of SABAs?
Salbutamol
Terbutaline
What are some side effects of beta 2 agonists?
Adrenergic so tachycardia
Palpitations
Tremor
When should inhaled corticosteroids be added to asthma managerment?
When using SABA or have symptoms 3 or more times per week
How do corticosteroids relive symptoms in asthma?
Bind to glucocorticoid receptor in the cell for transrepression of inflammatory mediators which reduces inflammation in the bronchi
What is the first choice add on therapy for a px with symptomatic asthma already on SABA + ICS?
LABA
What must a LABA always be prescribed in conjunction with?
Inhaled ICS
as LABA is not anti-inflammatory
What are leukotreiene receptor antagonists and when are they indicated?
Leukotrienes induce bronchoconstriction, oedema and mucus so LRAs reduce these symptoms (but only work in approx 15% of px)
What type of drug is tiotropium?
Long acting muscarinic antagonist
What are some side effects of toptropium?
Dry mouth
Urinary retention
Glaucoma
How do drugs such as theophylline and aminophylline exert their action?
Antagonise adenosine receptors and inhibit phosphodiesterase (which breaks down cAMP7
What is the final step in asthma management?
Daily oral steroid e.g. prednisone
Deliver a higher and more efficacious dose when oral but more side effects as systemic effects
What is the PEFR for someone with moderate asthma?
50-75% predicted
What factors are typical of a diagnosis of severe acute asthma?
Unable to complete sentences
RR > 25
HR > 110
PEFR 33-50% predicted
What treatments are needed in acute asthma attack?
High flow O2
Nebulised salbutamol 5mg (can repeat after 15 minutes)
Oral prednisolone 40mg for 5-7 days
Which muscarinic receptor is tiotropium selective for?
M3
What are features of life-threatening asthma?
PEFR <33% predicted Cyanosis Fatigued Silent chest Hypotension Low pH Sats <92%
What factor indicates near fatal asthma?
When CO2 is rising
