| What is aspirin induced asthma? | acute idiosyncratic rxn leading to acute bronchospasm or angioedema (and rarely both)
Evolves over decades, begins as chronic rhinitis (recurrent sinusitis and polyposis)
Then asthma appears severe and requiring steroids
We note brochospasm after 30 min to hour of admin of aspirin, maybe cross sensitivity with NSAIDs (PG synthesis inhibitors), blocking cyclooxygenase pathway thus producing more LTs which are potent inflammatory mediators inducing asthma pathophysio
3-5% of asthmatics hospitalized as aspirin reaction.
Treatment avoidance/ desensitization by increasing dose of aspirin/ LT inhibitors and receptor antagonists |
| What is exercise induced asthma? | Nearly all asthmatics experience bronchospasm after exercise, 70-80% show decreased PF and FEV1 after 6 minute exercise challenge, during exercise they seem protected due to bronchodilation mechanism by catecholamines.
Cough and SoB parallel to decreased LF, symptoms abate without treatment, but can return immediately to normal function after admin of b-agonist.
Risk factors: poor control os asthma, exercise in cold (mast cell producing mediators), greater exercise intensity, bronchoconstriction is less in a second challenge after a first one in an hour, so warmup is helpful
Pretreatment can reduce it 90% (by b-agonist) |
| What are the objective measures of asthma? | PFT, spirometry, challenge testing, ABG.
portable monitoring can be useful
Challenge testing with aeroallergens, histamine and metacholine (20% drop in FVC indicates BHR)
Exercise testing helpful for children (15% decrease FEV1 is diagnostic and 20% decrease in PEFR from baseline 5-15 min as well) |
| Describe in general pharmacologic management of asthma? | Both short-term and long term.
Short term immediate relief of symptoms (relievers - bronchodilators), long term prevent disease (controlers -anti inflammatory) + avoidance |
| How is beta-agonist used in management of asthma? | Used for thousands of years (herb Ma Huang), relief symptoms of acute airway obstruction, smooth muscle relaxation by activating PKA, delivered by inhaler/ pouder/ nebulizer, but we are concerned of receptor desensitization so we use long-acting beta agonists (LABA) for long term maintenance and control (better than doubling dose of ICS or adding theophylline or LPM for example) |
| How are anti-cholinergics used in asthma management? | Compete with Ach blocking bronchoconstriction, Tiatropium benificial in severe asthma (admin with ICS/LABA), but some phenotypes are more likely to respond (fixed airway obstruction/ advanced age/ longer duration of disease) |
| How is theophylline used in asthma management? | Adjunct for pt with failed corticosteroid treatment, weak bronchodilation and anti-inflammatory effect, inhibit phosphodiesterase increasing cAMP.
We should monitor blood levels to avoid toxicity (especially elderly - GI side effects 20-30 microg/ml, cardiac arrhythmias, seizures, blood glucose 8-15 therapeutic) |
| How are anti-inflammatory agents used in asthma management? | Effective in reducing inflammation, improving lung function, decreasing BHR, reducing symptoms and improving QoL.
Cotricosteroids most effective |
| How is use of glucocorticoids in asthma management? | Improve symptoms and LF, decrease BHR, and mortality.
oral, PRL or inhaled.
oral prednisone used for acute exacerbation unresponsive for bronchodilators
Safe and effective for moderate-severe cases used for years ICS (inhaled corticosteroids)
Beclomethasone, triamcinolone, fluticasone, budesonide, mometasone... (ICS)
impaired effect for smokers, and long term use is good safety profile
Recommended low dose in asthma symptoms (more than twice a week), waking due to asthma more than once in a month and any asthma symptom + any risk factor for exacerbation)
We should make sure right dx, symptom monitored, LFT, train pt to use drug, and follow up
High dose can cause Hypophyseal adrenal axis supression, local effects (horseness, dysphonia, cough and candidiasis) |
| How do we achieve control for asthmatics who remain symptomatic even after ICS? | add-on high dose ICS, theophylline, anti-LTs, LABA. |
| How are LT antagonists used in asthma management? | Effective controllers of inflammation, improve symptoms LF and decrease exacerbations.
Imp in exercise and aspirin induced
Used alone, less effective than ICS, safe-drugs, can be add-ons, improve control for pt not controlled by med-high dose of ICS
Inferior to LABA as add-ons to ICS |
| What is step 3 pharmacologic management of asthma? | Maintenance tx of Low dose ICS/LABA + SABA (when needed) or ICS/formoterol maintenance as relievers
Pt with >1 exacerbations Maintenance BDP/ BUD reliever more effective than the one up |
| How is omalizumab used in asthma management? | monoclonal Ab inhibiting IgE of mast cells complexating with them, tx of atopic asthma, reduction of exacerbation rate and reduce steroid use, improve QoL and symptom scores, administerd by injection, well-tolerated rarely causes anaphylaxis (only rarely) |
| How is allergen specific immunotherapy? | limited role of immunotherapy (requires identification of a small allergen very hard)
Improves symptoms, reduces requirements of meds, improves allergen specific ones
Considered only after failure of avoidance and mainstay of pharmacotherapy |
| Describe management of asthma in general. | Individualized, symptoms vary overtime, exacerbations determinant of long-term control
challenges include over reliance on rescue meds, suboptimal control, poor adherence to therapy, complexity of current treatments and lack of education.
So we need pt-dr partnership to get good self-management of pt. |
