ASTHMA Flashcards
Asthma basics (6 points)
- Affects the bronchi
- one of the most common chronic disease in children
- chronic airway inflammation + bronchoconstriction cause airway obstruction - expiratory airflow limitation
- results in recurrent episodes of (bcwc) breathlessness, cough, wheezing, chest tightness.
- most common complication - exacerbation - mild/severe/fatal
- there is no cure, can be controlled
diagnosis & assessment & asthma triggers
detailed history & physical examination
there is activation of inflammatory mediators (histamine, leukotrienes, cytokines) + increase in inflammatory cells (eosinopils, mast cells)
genetic predisposition - mediated by IgE or eosinophilic asthma
dx confirmed by spirometry & pft
triggers - genetics, smoke, dust, pollen, pet, cold air, pollution, perfume nd cosmetics, drugs (beta blockers, nsaids, aspirin)
spirometry - tests o well the lung works
FEV1 - how much air can be forcefully exhaled in 1 second
FVC - after a deep breath, the max volume of air that is exhaled
FEV1/FVC - % of total air capacity that can be forcefully exaled in 1 sec
treatment basics
- reduce impairment (night time symptoms, frequency of rescue inhaler use, limitation to normal activity) & reducing risk (exacerbations, hospitalizations & med averse events)
- avoid exposure to tobacco smoke, encourage quitting
- annual influenza vaccine is recommended
- rescue/relievers inhalers - rapid action - frequent use means worsening of symptom. can be used to prevent eib
- controllers/maintenance inhaler - taken chronically to maintain symptoms.
relievers
- Inhaled low dose ICS + formoterol
- inhaled SABA
- systemic steroids - during exacerbations
- inhaled epi
- inhaled SAMA - used in combination
relievers
- Inhaled low dose ICS + formoterol
- inhaled SABA
- systemic steroids - during exacerbations
- inhaled epi
- inhaled SAMA - used in combination
controllers
- ICS - first line
- inhaled LABA - used in combination
- oral leukotriene receptor antagonists - commonly used in children
- theophylline - monitor serum levels
- LAMA
- injectable monoclonal antibodies - omalizumab for severe allergic asthma, mepolizumab, reslizumab, benralizumab, dupilumab for severe eosinophillic asthma
inhaled corticosteroids
inhibit the inflammatory response
reduce symptoms, increase lung function, improve quality of life, reduce risk of exacerbations
1. budesonide - 90/180 mcg/inh
2. fluticasone
3. beclometasone
high doses for long term can cause adrenal suppression, risk of fractures increase, growth retardation, immunosuppression
beta 2 agonists
binds to beta 2 receptors in lungs causing relaxation of bronchial smooth muscle - bronchodilation
1. albuterol - 90 mcg/inh
SE - nervousness, tremor, palpitations, cough, hyperglycemia, hypokalemia
to prevent exercise induced bronchospasm use 2 inhalations 5 minutes prior to exercise.
2. salmeterol - 50mcg/inh
increased risk of asthma related deaths
Controller inhalers
- ICS - budesonide, beclomethasone, fluticasone
- LABA - salmeterol
- LAMA - tiotropium
- ICS/LABA - budesonide/formoterol, fluticasone/salmeterol
MDI vs DPI
MDI - aerosolized liquid, spacer is helpful, administration requires slow and deep inhalation at the same time as pressing the canister
DPI - fine powder, no propellant, do not shake, no need for spacer, administration requires quick and forceful inhalation
Leukotriene modifying agents
- LRA - inhibit leukotriene mediators of airway inflammation. Reduces airway edema, constriction and inflammation. Montelukast (LTD4I), zafirlukast (LTD4I & LTE4I)
Montelukast - 10mg daily eve, (6-14) 5mg od, 1-5 4mg od
Warnings - neuropsychiatric events (aggressive behavior, hostility, agitation, hallucination, depression, suicidal thinking). Systemic eosinophila with vasculitis like churg strauss syndrome
SE - headache, dizziness, abd pain - Zileuton - lipoxygenase inhibitor, inhibits leukotriene formation.
Theophylline
Blocks phosphodieterase - increase camp - increase release of epi from adrenal medulla - bronchodilation.
Also causes diuresis, cns & cardiac stimulation & gastric acid secretion.
Limited use due to decreased effectiveness and drug interactions and adverse events.
Active metabolites - caffiene, 3-methylxanthine
Signs of toxicity - persistent vomiting, arrhythmia, seizure
Drugs that can increase theophylline level (cyp1a2) - ciprofloxacin, propranolol, zafirlukast, zileuton
Conditions that can increase theophylline level - alcohol, allopurinol, disulfiram, oral contraceptive with estrogen, verapamil, mtx, pentoxifylline, propafenone
Drugs & conditions that can decrease theophylline level - carbamazepine, fosphenytoin, phenobarbital, phenytoin, primidone, rifampin, riyonavir, tobacco/marijuana smoking, high protein diet charboiled meals
Theophylline will decrease lithium by increasing renal elimination of lithium.
Anticholinergics
Inhibit muscarinic cholinergic receptors and reduce the intrinsic vagal tone of the airway - bronchodilation.
SAMA & LAMA
Omalizumab
Monoclonal antibody that inhibits igE binding to the ige receptor on mast cells and basophils. Indicated for moderate to severe persistent asthma in patients >6 yrs if a skin test to perennial allergen is positive and symptom control is inadequate with steroids.
Watch for anaphylaxis
