Asthma Flashcards
State the sympathetic and parasympathetic innervation of the resp system and effects thereof
B2 adrenoceptors (cause relaxation of bronchial smooth muscle, leading to dilation)
M3 receptors: cause bronchial muscle contraction»_space; bronchoconstriction
Common symptoms of pulmonary disease
Wheezing
SOB
Cough (wet or dry), or hemoptysis
chest pain
What causes respiratiory conditions? (2)
Infection
Malignancy
What is asthma? Explain. (2)
Inflammatory condition with
recurrent reversible airway
obstruction in response to
irritant stimuli.
* Intermittent attacks
Common sysmptoms of asthma(4)
Symptoms include wheezing,
shortness of breath, difficulty
breathing out, sometimes cough
(worse at night)
Who mostly become affected by asthma?
Common in children with atopy
(allergic rhinitis and atopic
dermatitis) = allergic asthma
Asthma is characterised by: (3)
Inflammation of the
airways
* Bronchial
hyperreactivity
* Reversible airway
obstruction
What happens in the immediate phase of asthma?
Inciting agent: alletgen or non-specific stimulant» activation of mast cells and mononuclear cells»_space; release of H, cystLTs, and PGD2, AND release of chemokines and chemotaxins»_space; Bronchospasm
What is the treatment of immediate phase asthma?
M3 antagonists
B2 adrenoceptor agonists
cysLT antagonists
Theophylline
Explain the late phase of asthma
The chmokines released during the immediated phase will lead to the production of chemokine releasing Th2 cells, mononuclear cells and inflammatory cells esp eosinophils»_space; release of cysLT, NO, adenosine, neuropeptides, AND Eosinophil Major Basic Protein (EMBP) and Eosinophil Cationic Protein (ECP).
EMBP and ECP cause epithelial cell damage, which causes airway hyperactivity. Together with other secretions, also causes Airway inflammation.
All this ultimately leads to bronchospasm, wheezing, and coughing
Treatment of the late phase
Glucocorticoids
What does PEFR do? Why is it important?
Volume of air forcefully
expelled from the lungs in
one quick exhalation
* Reliable indicator of
ventilation adequacy as
well as airflow obstruction.
List 3 factors leading to differences in PEFR
Age, Height, Sex
How does one calculate predicted peak flow rate? (4)
CALCULATING % PREDICTED PEAK
FLOW RATE
* Take the best of 3 of the patient’s observed peak flow rate
* Find the patient’s sex, age and height predicted value from nomogram or table:
* Divide patient’s observed peak flow rate over their predicted peak flow.
rate
* Multiply by 100
List 5 drug classes used in the treatment of asthma
B2 agonists
M3 antagonists
Glucocorticoids
Xanthines
Leukotrine receptor antagonist
Examples of B2 adrenoceptor agonists. Classify into short acting and long acting
Salbutamol and fenoterol, terbutaline - SABA,
Salmeterol and Formoterol - LABA
Examples of M3 antagonists and ROA
iptratropium bromide, tiotropium (Inhaled)
Examples of Glucocorticoids and ROA
Beclomethasome, budesonide, fluticasone (INHALED)
Examples of Xanthines and ROA
Aminophylline, theophylline (IV, Oral)
Examples of Leukotriene receptor antagonists and ROA
Montelukast, ORAL
What is the MOA of B2 agonists?
β₂ activation causes relaxation of the bronchial smooth muscle
* May increase mucous clearance by an action on cilia
SABA clinical use/indication, ROA,
Onset of action (time),
Max effect (time),
overall duration of action (time)
Clinical use/indication: acute bronchospasm
* Inhaled (Onset of Action: 5-15 min)
* Max effect within 30 min
* Duration of Action: 4-6 hrs
Salbutamol dosage
1 or 2 puffs, prn as required
________________ can develop to bronchodilator effects
with continuous/inappropriate use.
Tolerance
Indication of LABA
COPD, Uncontrolled persistent asthma