Martin Asthma Lecture Flashcards
beta agonist Bronchodilators
Short-acting b agonists (SABA)
Albuterol, others
Long-acting b agonists (LABA)
Salmeterol, formoterol
Emergency, non-selective b agonist
Epinephrine
Muscarinic Antagonists
Ipratropium, tiotropium
Methylxanthine
Theophylline
Inhaled Corticosteroids (ICS)
Beclomethasone Budesonide Ciclesonide Flunisolide Fluticasone Mometasone Triamcinolone
Oral Corticosteroids
Methylprednisolone
Prednisone
Leukotriene Receptor Antagonist (LTRA)
Montelukast
Zafirlukast
Cromolyn compounds
Cromolyn sodium
Anti-IgE Antibody
Omalizumab
Bronchospasm
In allergic asthmatics patients, immediate hypersensitivity-type reactions can be continuously present at a sub-threshold level, resulting in mild-to-moderate inflammation without overt bronchoconstriction.
Overt bronchospasm then occurs upon exposure to a specific allergen or to a variety of nonspecific stimuli, e.g., cold air, dust, air pollution, exercise, etc.
Inflammatory Mediators in Asthma
Enormous variety of mediators are released. Thus, blocker of a single mediator, e.g., antihistamine, is unlikely to be effective in alleviating the symptoms or the progression of asthma.
Corticosteroids, which are capable of blocking many key steps in the inflammatory process, come closest to this ideal therapy.
Mast Cell Mediators of Inflammatory Processes
Preformed (immediate): Histamine, TNF-alpha, Proteases, Heparin –> Bronchoconstriction,
itch, cough, vasodilation, edema
Lipids (minutes): leukotrienes, prostaglandins –> bronchoconstriction, chemotaxis, mucus secretioin
cytokines (hours): interleukins, GM-CSF –> bronchoconstriction, chemotaxis, inflammatory cell proliferation
Aerosol Delivery of Drugs
Particle size of aerosol is important.
Rate of breathing and breath holding.
Even under ideal conditions, 90% of inhaled drug is swallowed.
Therefore, ideally the best drugs also have poor absoption from the GI tract and/or rapid first-pass metabolism in the liver.
Aerosol Delivery of Drugs
Metered Dose Inhalers (MDI)
with spacer device
Nebulizers
Dry powder inhalers
classification of pts who are not taking long-term control meds
intermittent FEV1 > 80%
mild FEV1 > 80% and minor limitation to normal activity
moderate FEV1 60-80
severe FEV1 less than 60
Stepwise treatment kids 5-11
Step 1: SABA PRN
Step 2: low dows ICS (alternative: cromolyn, LTRA, nedacromil, oro theophylinie)
Step 3: lowdose ICS + either LABA, LTRA, or theophylline OR medium dose ICS
Step 4: medium dose ICS + LABA. Alternative: ;med dose ICS + either LTRA or theophyline
Step 5: High-dose ICS + LABA . alternative: High-dose ICS + either LTRA or theophyline
Step 6: high dose ICS + LABA + oral systemic corticosteroid. alternative: high-dose ICS + either LTRA or theophylline + oral systemic corticosteroid
beta Adrenergic Agonists use in asthma and COPD
Therapeutic Use in Asthma and COPD:
Drug of choice for rapid relief of bronchospasm
Highly effective and safe for intermittent, prophylactic treatment of asthma.
Current Emphasis:
Intermittent use on an as-needed basis for relief of acute, severe bronchospasm. Not general prophylaxis.
Overuse:
Side effects intensify will overuse, but a greater danger is the tendency to continue to self-medicate during periods when symptoms are escalating.
To avoid a medical emergency, patients should be encouraged to seek medical attention as soon as possible after they detect a decline in the efficacy of their usual therapeutic regimen.