Asthma Flashcards
B agonists - short acting
Albuterol, levalbuterol, pirbuterol, terbutaline, bitolterol
- used to stop an asthma attack in progress
- Albuterol, pirbuterol, terbutaline, bitolterol have a half life of 4-8hrs
- Levalbuterol- l-isomer of albuterol, more bronchodilation with few side effects
- alberterol and terbutaline: inhaled and oral
- albuterol and levalbuterol: nebulizers
B-agonists - long acting
Salmeterol, salmeterol/fluticasone (advair), formoterol, formoterol/mometasone (dulera), aformoterol, indacaterol, olodaterol, vilanterol/fluticasone
- last for 12hrs
- bronchoselective, given prophylactically, takes 20mins to take effect, not effective for relief of an asthma attack in progress
- arformoterol, indacaterol, olodaterol: COPD use
** should always be given with a corticosteriod
SE: see handout!!!
Ipratropium, Tiotropium (spiriva)
- Muscarinic Antagonist
- Quaternary ammonium compounds, not absorbed systematically- stay in lung,
- tiotropium longer duration of action than ipratropium- 1 day admin, for pts who don’t respond to ipratroprium - Indications
- used for COPD
- used in conjunction with B2 agonist when B2 agonist alone is not sufficient
- bronchodilation occurs more slowly - SE:
- Cough, dry mouth, nausea, paradoxical bronchoconstriction
- inc intra-ocular pressure
Theophylline
- Asthma drug - CNS stimulant which acts like caffeine, dec. fatigue and elevating mood
- MOA:
- Blocks adenosine receptors which normally cause bronchoconstriction and cause release of inflammatory mediators in the lung
- also a Phosphodiesterase inhibitor, inc. amount of cAMP- which mimics the effects of bronchodilating NT - Indications
- very effective bronchodilator: relaxes SM esp bronchioles,
- stimulates cardiac muscle
- acts as a diuretic
- used in pts who do not respond to B2 agonists alone and in COPD
- Low therapeutic index - oral drug, rate of absorption varies from pt to pt, don’t switch btw brands- generic drug issues,
Metabolized in liver:
- clearance inc. 2x by phenytoin, smoking, rifampin, and oral contraceptives also inc. clearance
- Cimetidine and erythromycin: dec clearance
- Elimination slowed in pts with cirrhosis, CHF, and acute pulmonary congestion - SE
- CNS: nervousness, insomnia, similar to caffeine
- Cardiac: inc. rate and force of contraction, higher doses: tachycardia, and may predispose to arrhythmia
- Muscle: inc. contractility of the diaphragm, and dec. fatigue
- weak diuretic effect - Toxicity
- Overdose can be fatal, usually due to arrhythmia,
moderate toxicity: HA, palpitations, dizziness, nausea, hypotension,
higher doses: tachycardia, severe restlessness, agitation, emesis
- focal and generalized seizures can also occur
Oral steroid
Methylpredisolone, Prednisone
- used in severe cases of asthma when inhaled and other will not work
- Also used prophylactically if pts go into situations where asthma could worsen
- used for short periods of time to bring sx under control therefore limited side effects
SE with long term use:
- same as with glucocorticoid activity: thinning of skin, osteoporosis, hyperglycemia, truncal obesity,
SE with short term use:
- hyperactivity, GI disturbances, restless, psychotic events- resolve when drug stopped
Omalizumab
- monoclonal ab targeted to IgE, prevents binding to mast cells and basophils
- Used to prevent allergic rxns in pts w/moderate to severe asthma
- may decrease need for steroids and reduce exacerbations
- being used for food allergies as well
- SC injections every 2-4 wks, may cause serious allergic skin rxns
Cromolyn sodium, Nedcromil
- not bronchodilators; inhibit release of histamine from mast cells
- used to tx asthma, especially children
- inhaled admin
- used several times/day, chronically for prophylaxis
- 2-3 months for effect to be seen
- can prevent development of asthma in response to allergens and induced by exercise
- SE: bad taste is most common complaint
Zafirlukast, Montelukast, Pranlukast
Block leukotriene receptor
Zileuton
Blocks 5-lipoxygenase and dec synthesis of leukotrienes, may dec asthmatic rxn to aspirin and NSAIDs
Roflumilast
Inhibits PDE4; dec inflammation
B2 agonist
MOA: activate AC –> Inc cAMP –> dec. Ca2+ –> muscle relaxation
- also stabilization of the mast cells
- generally inhaled: localizes the activity and dec. the side effects
- intensity and duration are dose dependant
Side effects:
- inhaled: tachycardia, nervousness, and tremor (ppl will become tolerant the side effects)
- oral: more side effects- HA, nervousness, anxiety, and muscle tremor - tolerance will develop
- Long term use causes B2 receptor down-regulation- administer inhaled steroid to prevent down-regulation
Additional:
- a CORTICOSTERIOD should alway be prescribed with long acting b-agonists
- Pts. should be given a rescue inhaler (short acting) in addition to the long term b-agonist
Corticosteroids in Asthma (oral and inhaled)
Purpose: dec inflammation
- inhaled CS should always be prescribed with a long acting B2 agonist
- Improve the sx and dec the requirement for B-agonists
- beneficial effects begin in 1 wk
Corticosteriods in asthma (inhaled)
- beclomethasone, budesonide, fluticasone, flunisolide, triamcinolone
SE:
thrush, voice hoarseness, modest dec in bone density - reduce SE by using a spacer: dec the amount that is swallowed
