Asthma Flashcards
Controllers
CLAS: ICS, Na cromoglycate, Leukotriene-receptor antagonist, mAb (Anti-IgE, anti-IL5, anti-IL4R)
Reliever
BMT: SABA, LABA, COPD LABA, Theophylline, SAMA, LAMA
Example of ICS
Fluticasone
MoA of ICS
Anti-inflammatory:
Decreased inflammatory cells in airways — T cells, mast cells, macrophages and especially eosinophils for allergic asthma but no effect on neutrophils
Increased Annexin-1 but decreased COX 2, 5-LOX, PLA2 expression
Decrease cytokines
Use of ICS
1st line prophylactic therapy, decrease nocturnal asthma
Efficacy of ICS
Do not relax airway directly
Decreased risk of death from asthma
Decrease airway hyperresponsiveness in a few weeks
Decreased frequency of asthma
SE of ICS
Oropharyngeal candidiasis, cough, throat irritation
Some systemic effects (easy bruising in elderly, osteoproosis, adrenal suppression for fluticasone) present but lower risk of these
MoA of Na Cromoglycate
Mast cell stabilizer —prevents degranulation of mast cells –> prevent histamine, PG, leukotriene release
Promotes annexin-A1 secretion –> blocks histamine release
Blocks inflammatory mediators release
SE of Na Cromoglycate
Thorat irritation, dry mouth, cough, unpleasant taste
MoA of LTRA
Montelukast: competitive antagonist of cysteinyl leukotriene (CysLT1) receptor
Use of LTRA
Exercise and aspirin-induced asthma
SE of LTRA
Rarely get psychological reactions such as agitation, depression, hallucination
Efficacy of LTRA
Less effective than ICS but reduces use of ICS, decrease frequency of asthma exacerbation
Use of Na cromoglycate
Controller of asthma, control allergic rhinitis/conjunctivitis
Omalizumab
Anti-IgE mAb —effective for allergic asthma & rhinitis
SQ injection every 2-4w, $$$
MoA of omalizumab/IgE mAb
Bind to free IgE, decreases cell-bound IgE
Decrease expression of FcERI receptors, decrease mediator release
Decrease allergic inflammation
Prevent exacerbation of asthma
Anti-IL-5(R) mAb
Inhibit eosinophil function by binding and neutralizing IL-5 or targets & blocks IL-5R
Expensive treatment
Examples of B2 agonist
Non-selective: Epinephrine
SABA: salbutamol
LABA: salmeterol, formoterol
LABA for COPD: indacaterol
Duration of action
SABA 4-6h
LABA: 12h
LABA COPD: 24h
Use of ICS-LABA
ICS-Formoterol as preferred reliever for Px not on ICS-maintenance
If on ICS-maintenance, use SABA salbutamol as reliever on PRN basis
ICS-LABA for LT maintenance of asthma including nocturnal asthma
SE of B2 agonist
FIne tremor of skeletal muscle, muscle cramps
Palpitations, tachycardia
HypoK/Hyperglycaemia
*** Black box warning for LABA: asthma-related death due to tolerance
MoA of Theophylline
Inhibit PDE, block adenosine receptor
Increased epinephrine release –> BD effect
Use of theophylline
Add=on therapy to B2 agonist and ICS
Slow-release for nocturnal bronchospasm
Improve COPD lung function
SE of theophylline
Narrow therapeutic range — caution for potential DDI
GI: N&V, anorexia
CNS: nervousness, headache, anxiety
CV: arrhythmias
Muscarinic antagonist
SAMA: ipratropium bromide
LAMA: tiotropium bromide
MoA of SAMA/LAMA
Inhibit M3 receptor activated bronchoconstriction
reverse vagal-induced bronchospasm and mucus secretion
Uses of SAMA/LAMA
Add-on to B2 agonist, ICS
Patients intolerant of B2 agonist
Greater BD effect in COPD — tiotropium > ipratropium
SE of SAMA/LAMA
Unpleasant taste
Dry mouth, urinary retention in elderly —muscarinic antagonism effect
Paradoxical bronchospasm
