Asthma and drugs Flashcards
asthma mechanism
bronchial hyperresponsiveness causes reversible bronchoconstriction
asthma can be triggered by
- viral URI
- allergens
- stress
- exercise
- tobacco
test asthma with
metacholine challenge
asthma symptoms and clinical findings
- cough 2. wheezing 3. tachypnea 4. dyspnea
- hypoxemia 6. decreased inspiratory/expiratory ratio
- puslus paradoxous 8. mucus plugging
pulsus paradoxus - seen in
- cardiac teponade 2. asthma 3. obstructive sleep apnea
4. pericarditis 5. croup
pulsus paradoxus - definition
decreased in amplitude of systolic BP by >10 during inspiration
inspiratory/expiratory ratio in asthma
and why
decreased
expiration is prolonged
asthma - histology
- smooth muscle hypertrophy
- Curschmann spirals
- Charcot - Leyden crystals
Curschmann spirals
shed epithelium forms whorled mucus plugs (IN ASTHMA)
Charcot - Leyden crystals
eosinophilic, hexagonal, double-pointed, needle-like crystal from breakdown of eosinophils in sputum (IN ASTHMA)
Charcot - Leyden crystals - seen in
asthma
asthma bronchoconstriction is mediated by
- inflammatory process
2. parasympathetic tone
asthma drugs
- β2 agonists (albuterol, salmeterol, formoterol)
- corticosteroids (fluticasone, budesonide)
- Muscarinic antagonists (ipratropium)
- Antileukotrienes (montelukast, zafirlukast, zileuton)
- omalizumab
- Methylxanthines (theophylline)
- Metacholine
asthma - β2 agonists drugs
- albuterol
- saleterol
- formoterol
asthma - albuterol mechanism of action
β2 agonists–> relaxes bronchial smooth muscle
asthma - albuterol used in
during acute exacerbation
asthma - salmeterol mechanism of action
β2 agonists–> relaxes bronchial smooth muscle
asthma - formoterol mechanim of action
β2 agonists–> relaxes bronchial smooth muscle
asthma - β2 agonists mechanim of action
relaxes bronchial smooth muscle (increase cAMP)
asthma - salmeterol side adverse effects
- tremor
2. arrhythmia
asthma - formoterol side adverse effects
- tremor
2. arrhythmia
asthma - corticosteroids drugs
- fluticasone
2. budesonide
role of corticosteroids (fluticosine, budesonide) in asthma therpay
1st line therapy for chronic asthma
asthma - corticosteroids (fluticosine, budesonide) - mechanism of action
Inhibit the synthesis of virtually ALL CYTOKINES. Inactivate NF-kB, the transcription factor that induces production of TNF-a and other inflammatory agents
asthma - muscarinic antagonists drugs
- ipratropium
2. Tiotropium
asthma - muscarinic antagonists (ipratropium, tiotropium) mechanism of action
competitively blocks muscarinic receptors, PREVENTING BRONCHOCONSTRICTION
lung - muscarinic antagonists (ipratropium, tiotropium) -
used in
- athma
2. COPD
asthma - muscarinic antagonists (ipratropium, tiotropium) - except asthma is used in
COPD
asthma - ipratropium vs tiotropium according to action
tiotropium is long acting
metacholine mechanism of action
Muscarinic receptor M3 agonist –> bronchoconstriction
metacholine - used in
used in bronchial challenge test to help diagnose astma
asthma challenge test can also be with
histamine
omalizumab - mechanism of action
Monoclonal anti-IgE antibody. It binds mostly unbound serum IgE and blocks binding to FcεRI
omalizumab used in
allergic asthma resistant to inhaled steroids and long-acting β2-agonist
omalizumab binds mostly
unbound serum IgE
athma - antileukotrienes drugs
- montelukast
- zafirlukast
- Zileuton
montelukast, zafirukast mechanism of action
block leukotriene receptor (CysLT1)
Zileuton mechanism of action
5-lipoxygenase pathway inhibitor. Block conversion of arachnoid acid to leukotrienes
montelukast, zafirukast - clinical use
asthma (especially aspirin-induced asthma)
zileuton side effect
hepatotoxicity
asthma - methylxanthines drugs
Theophylline
theophylline mechanism of action
inhibits phosphodiesterase –> increased cAMP –> BRONCHODILATION
theophylline is metabolized by
cytochrome P-450
theophylline block action of
adenosine
adenosine receptor antagonists
- theophylline
2. caffeine
theophilline usage in asthma is limited because
narrow therapeutic index
theophylline adverse effects
- cardiotoxicity
2. neurotoxicity
asthma related response to mediators (leukotrienes, histamine etc) is divided to
early response –> bronchoconstriction –> symptoms
late response –> inflammation –> bronchial hyperreactivity
late response in asthma?
inhibitors of this response?
inflammation
inhibited by steroids and abtuleukotrienes
early response in asthma?
inhibitors of this response?
bronchoconstriction
inhibited by β-agonists, theophylline, muscarinic, antagonists
cAMP in asthma therapy
it induces bronchodilation
adenosine in lungs
bronchoconstriction
ach in lungs
bronchoconstriction
asthma treatment for acute exaceberation
albuterol
1st line therapy for chronic asthma
corticosteroids (fluticasone, budesonide)
aspirin-induced asthma treatment
montelukast
zafirlukast
asthma drug with cardiotoxicity as a side effect
theophylline
asthma drug with hepatotoxicity as a side effect
zileuton
asthma drug with neurotoxicity as a side effect
theophylline
asthma drug with narrow therapeutic index
theophylline
allergic asthma resistant to inhaled steroids and long acting β-agonists
omalizumab
omalizumab binds mostly unbound serum IgE and blocks
binding to FcεRI
asthma’s symptoms vary over in time in their
- occurrence
- frequency
- intensity
causes of prolonged expiration
- bronchoconstriction (airway narrowing)
- airway wall thickening
- increased mucus
symptoms of asthma may be triggered or worsened by factors such as
- viral URI
- allergens
- stress
- exercise
- tobacco
asthma full treatment
there is not full treatment, only control
bronchial hyperresponsiveness in asthma is due to
inflammation
think asthma as a diagnosis when
- Recurrent episodes of wheezing
- Cough at night
- Coughing or wheezing after exercise
- Cough, wheezing, chest tightness after exposure to allergens or pollutants
- Colds “go down to the chest” or take longer than 10 days
