Asthma Flashcards
how is asthma characterized?
paroxysmal or persistent symptoms
dypsnea, chest tightness, wheezing, sputum production & cough
airway hyper-responsiveness to a variety of stimuli
does asthma alter lifespan?
no
in children is there more males or females with asthma?
males
environmental factors contributing to asthma
tobacco smoke
allergen exposure
infections in infancy
environment
occupational sensitizers
exercise
drugs/preservatives
diet
atopic vs non-atopic asthma
atopic - extrinsic - allergy to antigens
non-atopic - intrinsic - secondary to chronic/recurrent infections
effect of age on asthma
most diagnosed by age 5
predictors of persistent adult asthma include:
atopy
onset during school age
presence of BHR
pathophysiology of asthma
bronchial hyper-reactivity of airways to physical, chemical & pharmacologic stimuli is the hallmark of asthma
bronchospasm
constriction of the muscles in the walls of the bronchioles
hyper-reactivity
an exaggerated response of bronchial smooth muscles to trigger stimuli
airway remodeling
refers to structural changes leading to airway obstruction, may eventually become only partially reversible
what causes airway inflammation?
CD4+, T lymphocytes, eosinophils, mast cells
types of asthma
early asthmatic response - minutes
late asthmatic response - hours
chronic asthma - days
asthma phenotype 1
obesity-related
very late onset
smoking related
comorbidities
asthma type 2
early onset allergic asthma
later onset eosinophilic asthma
aspirin exacerbated respiratory disease
exercise induced asthma
elements of asthma diagnosis
medical history
physical exam
pulmonary function test
other lab tests
symptoms of asthma
intermittent episodes of expiratory wheezing, coughing and dypsnea
chest tightness and chronic cough in some
triggers of asthma
exercise-induced bronchospasm
time of day
aero-allergens
irritants
respiratory tract infections
weather
psychological factors
hormonal fluctuations
GERD
medications
preservatives
why id a physical exam a poor indicator of asthma?
because asthma is a disease of exacerbation and remission, so the patient may not have any signs or symptoms at the time of the exam
what may be observed during a physical exam?
expiratory wheezing on ausculation
dry hacking cough
signs of atopy (allergic rhinitis and/or eczema)
why is a pulmonary function test necessary for asthma diagnosis?
to establish diagnosis, assess severity and treatment response
adult criteria of pulmonary function in asthma
FEV1/FVC < 75-80% predicted
12% improvement in FEV1 & at least 200ml from baseline 15 minutes post quick acting 2-agonist challenge or after a course of controller therapy
preferred criteria for a diagnosis of asthma
spirometry showing reversible airway obstruction
lab tests for asthma diagnosis
CBC, eosinophil count, IgE concentration, FeNO
allergy skin tests
sputum eosinophils
what is the Canadian thoracic society? (CTS)
Canada professional organization which promotes lung health and provides best respiratory practices
what is global initiative for asthma? (GINA)
developed in collaboration with experts from many countries
NOT a guidline, but a practical approach to managing asthma in clinical practice - updated yearly
what is the CTS definition of asthma control for each:
daytime symptoms
night symptoms
physical activity
exacerbations
absence from work or school
need for a reliever
FEV1 or PEF
PEF diurnal variation
sputum eosinophils
daytime symptoms </= 2 days/week
nighttime symptoms < 1 night/week and mild
physical activity - normal
exacerbations - mild and infrequent
absence from work or school due to asthma - none
need for a reliever - </= 2 doses per week
FEV1 or PEF >/= 90% of personal best
PEF diurnal variation < 10-15%
sputum eosinophils < 2-3%
asthma is well controlled when a patient can:
avoid symptoms during the day and night
need little or no reliever mediaction
have productive, physically active lives
have normal or near-normal lung function
avoid serious asthma flare-ups
goals of therapy for asthma
prevent asthma-related mortality
maintain normal activity levels
prevent daytime and nocturnal symptoms
maintain normal spirometry
prevent exacerbations
provide optimal pharmacotherapy and avoid side effects
principles of asthma treatment
environmental control
pharmacologic treatment
appropriate use of inhalation therapy
regular consultation with certified asthma educator
graduated approach to therapy
regular follow-up
types of asthma triggers
endogenous stimuli - stimuli generated inside the body
exogenous stimuli - stimulie generated outside the body
what is the reliever?
short-acting beta-adrenergic agonists (SABA)
what is the controller?
long-acting beta-2 agonists (LABA)
MOA of SABAs
selective beta 2 adrenergic agonists
- smooth muscle relaxation
onset within 5 minutes peak effect on FEV within 30 minutes
indication of SABAs
prevention of exercise-induced or cold air induced bronchospasm
treatment of intermittent episodes of bronchospasm
what does the structure of a SABA determine?
the selectivity, potency, duration of action and oral activity
what are the SABAs?
salbutamol
terbutaline
metaproterenol
isoproterenol
epinephrine
which two SABAs are preferred due to their selectivity for B2?
salbutamol and terbutaline
adverse effects of SABAs
tachycardia, palpitations
skeletal muscle tremor
nervousness, irritability, insomnia, headache
BP changes
cardiac arrhythmias
increased BG
hypokalemia at high doses
tachyphylaxis
what drug interactions do SABAs have?
beta-blockers: oppose effect
loop or thiazide diretics: increase risk of hypokalemia
tricyclic antidepressants: may increase ADRs of SABA
how are SABAs usually dosed?
1-2 puffs every 4-6 hours as needed
how do LABAs work?
work slowly over a 12-hour period to keep airways open and muscles relaxed
what are the LABAs?
salmeterol - partial agonist
formoterol - full agonist
vilanterol - full agonist
indacaterol - full agonist
which LABA is approved for rescue therapy?
formoterol
which LABAs are available in combo products only?
vilanterol
indacaterol
what are the DOAs of the LABAs?
> 12 hours: salmeterol, formoterol
24 hours: vilanterol, indacaterol
what are the most effective anti-inflammatory drugs available for asthma?
corticosteroids
what is the most common type of controller medication?
inhaled corticosteroids
how do ICSs work?
improve lung function
decrease frequency /severity of attacks
increase QOL
decrease asthma mortality
MOA of ICSs
inhibit inflammatory response at all levels
inhibits the late asthmatic response & decreases bronchial hyper-responsiveness in asthma
what are the ICS drugs?
fluticasone propionate
fluticasone furoate
budesonide
ciclesonide
beclomethasone
mometasone
when are ICSs preferred?
in pregnancy
which ICSs are approved for use in all ages?
fluticasone propionate
which ICSs are approved for use in 6-11 years of age?
beclomethasone dipropionate (low)
budesonide (low)
ciclesonide (low)
fluticasone propionate (low and meddium)
mometasone furoate (low)
which ICS is only approved for adults 12 and older?
fluticasone furoate
side effects of ICSs
dysphonia, hoarseness, throat irritation, cough
candida oral infections (thrush)
growth retardation in kids
adrenal axis suppression if high doses
education points for ICSs
regular, daily use; delayed onset
rinse mouth & spit
address steroid phobia
wash face after use if using spacer with mask
efficacy reduced in patients who smoke
what drug do ICSs interact with?
desmopressin: highly increased risk of hyponatremia
when would oral/IV CSs be used?
for short periods of time in ACUTE, SEVERE asthma
short term effects of oral/IV CS
insomnia
increased activity
mood changes
water retention
hyperactivity in children
long term effects of oral/IV CS
increased appetite
weight gain
stomach irritation
cataracts osteoporosis
HPA axis supression
MOA of leukotriene receptor antagonists (LTRA)
antagonizes the effects of leukotrienes, which are formed by the breakdown of arachidonic acid in mast cells, eosinophils and other inflammatory cells
- reduces airway inflammation, small variable bronchodilator
side effects of LTRAs
headache
dizziness
heartburn
nausea
drowsiness
what drug is a LTRA
montelukast
when are LTRA given?
at night because their peak activity can occur at night
what are the advantages to combo products?
more convenient
enhanced adherence
ensures the patient receives their dose of inhaled corticosteroid
avoids SABA dependence
can you use a LABA alone?
no must be used with a corticosteroid
what combo product is for maintenance or relief?
symbicort - formoterol + budesonide
MOA of methylxanthines (theophylline)
non-specific inhibition of phosphodiesterase, which causes mild bronchodilation
increases diaphragmatic contractility and enhances mucociliary clearance
when is theophylline used?
as an ‘add on’ in patients that require high dose corticosteroid
used only in severe asthma cases
no role is rescue therapy
side effects of theophylline
diarrhea
nausea
heartburn
anorexia
headaches
nervousness
tachycardia
upset stomach
what is omalizumab?
a biologic that is an anti-immunoglobulin E antibody
it inhibits inflammatory response
when is omalizumab used?
when atopic asthma is poorly controlled despite high-dose inhaled steroids and appropriate add-on therapy, with or without oral prednisone
what are the new IL-5 inhibitors?
mepolizumab (>6)
reslizumab (>18)
benralizumab (>18)
what is the IL 4 and 13 inhibitor?
dupilumab (>12)
what are two other therapies for severe asthma?
tiotropium (>12)
macrolides - azithromycin (>18)
a higher risk for an exacerbation is defined by any of the following:
history of a previous severe asthma exacerbation
poorly-controlled asthma as per CTS criteria
overuse of SABA
current smoker
in what order are the drugs used to treat asthma?
start with SABA and ICS
increase ICS
add LABA
add LTRA
very mild asthma is well controlled on:
PRN saba only
mild asthma is well controlled on:
low dose ICS (or LTRA) + prn SABA OR
PRN bud/form (symbicort)
moderate asthma is well controlled on:
low dose ICS + second controller + prn SABA OR
moderate doses of ICS +/- second controller and PRN SABA OR
low-moderate dose bud/form + prn bud/form
severe asthma is well controlled on:
high doses of ICS + second controller for the previous year or systemic steroids for 50% of the previous year to prevent it from becoming uncontrolled, or is uncontrolled despite therapy
what is the difference between uncontrolled asthma and severe asthma?
anyone can have uncontrolled asthma and it is when a previously asymptomatic patient intermittently develops symptoms and can be addressed with self-management education and an action plan. severe asthma remains poorly controlled despite best practices.
how often should asthma be reviewed?
1-3 months after starting treatment and then every 3-12 months
when can you consider stepping down treatment?
in stable patients
>3 months of control
goal is to find the lowest effective dose
what should be included in an asthma action plan?
how to monitor and measure their symptoms
daily preventative management strategies
when and how to adjust medications
when to seek urgent care
when is a peak expiratory flow meter used?
for moderate-severe asthmatics or asthmatics who are poor perceivers of airway obstruction
when following an action plan when should someone seek emergency medical care?
when their expiratory flow is <60% of best
risk factors of exacerbations
poor adherence
suboptimal ICS use
high SABA use
obesity
GERD
pregnancy
Low FEV
what is the first line treatment for ASA/NSAID induced asthma
leukotriene antagonists
if a b-blocker must be used which one should you choose?
a cardio-selective
