Transcript Basic Asthma Management Principles

Asthma Primer
Wayne Kradjan, Pharm. D.
Definition of Asthma
•
•
A chronic inflammatory
disorder of the airways…
In susceptible individuals, this
inflammation causes episodes of
wheezing, breathlessness, chest
tightness and coughing, particularly
at night or early morning.
• Usually associated with widespread
but variable airflow obstruction
(bronchospasm) that is often
reversible, either spontaneously or
with treatment.
• Inflammation also causes an increase
in bronchial hyperresponsiveness to
a variety of stimuli (triggers)
Large, “central”
airways
Small,
“peripheral”
Airways
Only site of
gas exchange
Causes of Airflow
Obstruction
•
•
•
•
BronchospasmHyperresponsiveness and
narrowing of airways (bronchi)
due to muscle spasm.
Airway edema (swelling of
walls)
Mucous plugging
All made worse by airway
inflammation
Bronchial
Hyperresponsiveness
•
More easily induced
bronchospastic response to a
variety of stimuli that may not
otherwise cause a response in the
general population.
– Allergens
– Chemicals, irritants
– Exercise
•
•
Response may also be more
intense and prolonged
Non-asthma patients may develop
a transient BHR after viral upper
respiratory infection.
Asthma Triggers
•
Allergens (seasonal/ perennial)
– Grass, weeds, pollen, mold, mildew
– Animal dander, saliva, dust mites
•
Chemical irritants and fumes
– Cigarette smoke, pollution, perfume
– Household cleaners, occupational
•
•
•
•
•
Viral infections, rhinitis,
sinusitis, (“post nasal drip”)
Gastroesophageal reflux (GERD)
Exercise; cold, dry air
Extreme emotions
Drugs (aspirin, beta blockers)
Measuring
Airflow Obstruction
•
Assessing air outflow
– Peak flow: Maximum rate
(L/min) of airflow out of the lung
during a forced exhalation.
– FEV1: Forced expiratory volume
in one second. Actual volume
(L) of air expired in the first
second of a forced exhalation.
– FVC: Forced vital capacity.
Total volume of air expired
during a forced exhalation.
Peak Flow Meter
Obstructive Airways Disease:
Sequence of Events
Inflammation, nerve exposure
Hyperresponsiveness
“Trigger”: allergen or irritant exposure
(cold air, exercise)
Bronchospasm ( FEV1, peak flow)
mucous, edema, cough
OBSTRUCTION
Epidemiology
•
5% of US population
• 5,000 deaths per year in US
• Higher incidence in inner city,
especially African Americans
and Hispanic populations.
– Racial vs. socioeconomic?
Environmental Factors
•
Increased time spent indoors
– Indoor allergens (molds, mites,
cockroaches)
•
Tobacco smoke exposure
– maternal smoking risk for child
•
Increased childhood infections
associated with lower risk
– Having older or multiple
siblings or day care center
attendance may lower risk
(more childhood infection)
– Hygienic hypothesis
Childhood onset
•
Most common chronic disease of
children (6.9% of population)
– More likely to be allergic basis
– Common: child with positive
family history of asthma and
allergy to tree and grass pollen,
house dust mites, household pets
and molds.
– 30-70% markedly improve or
symptom free as adult
Adult onset
•
•
•
•
•
May be allergic or non-allergic
Often negative family history and
negative skin tests to common
allergens
Often history of nasal polyps,
aspirin sensitivity and chronic
sinusitis
Environmental exposure: wood
dust, chemicals, pollutants at
workplace or in air
Chemical sensitizers: viral
infection, tobacco smoke, diet,
perfume
Expert Panel 2 Report
Guidelines for the Diagnosis
and Management of Asthma
NIH Publication #97-4051A
National Institutes of Health.
National Heart, Lung and Blood Institute
May 1997
http://www.nhlbi.nih.gov/
guidelines/index.htm
Schering, Astra-Zeneca,
or Glaxo-Wellcome
Update on Selected
Topics 2002
Guidelines for the Diagnosis
and Management of Asthma
NIH Publication #02-5075
National Institutes of Health.
National Heart, Lung and Blood Institute
November 2002
http://www.nhlbi.nih.gov/
guidelines/asthma/asthsumm.htm
J Allergy Clin Immunol.
2002;110:S1-S219 (Nov supplement)
Step Approach to
Classification
•
Mild Intermittent
– Sxs <2/week, PM sxs < 2/month
– PFTs >80%, < 20 variability
•
Mild Persistent
– Sxs 3-6x/ week; PM sxs 3-4/month
– PFTs >80%, 20-30% variability
•
Moderate Persistent
– Sxs daily; PM sxs > 5 per/month
– PFTs 60-80%, >30% variability
•
Severe Persistent
– Sxs continual; PM sxs frequent
– PFTs <60%, >30% variability
•
Acute exacerbations
Staging:
Further Considerations
•
•
•
•
•
•
•
Seasonality
Nocturnal symptoms
Exercise induced
Peak flow monitoring
Daily fluctuations
Cough variant
“Wheezy bronchitis” in
children
“Reliever”, “Rescue”
Drugs
•
Rapid acting bronchodilators
– beta adrenergic agonists
– intermediate duration (3-6 hrs)
» Often called “short acting”
– metered dose inhaler (MDI),
dry powder inhaler (DPI, breath actuated),
solution for nebulization
• Albuterol (salbutamol) (Proventil, Ventolin)
•
•
Levalbuterol (Xopenex)
Bitolterol (Tornalate)
Metaproterenol (Alupent, Metaprel)
Pirbuterol (Maxair)
Terbutaline (Bricanyl, Brethine)
•
(Epinephrine, isoproterenol, isoetharine)
•
•
•
Metered Dose Inhaler
Albuterol (Proventil HFA)
Air Jet Nebulizer
Anticholinergic
bronchodilators
•
Ipratropium (Atrovent)
Tiotropium (Spiriva)
•
MDI (Atrovent and Spiriva)
– Also combination with albuterol: Combivent
•
Solution for nebulization (Atrovent)
– Also combination with albuterol:
DuoNeb (500 mcg/2.5 mg)
•
Slower onset, longer acting than
albuterol
– Atrovent QID; Spiriva QD
•
Dry mouth and blurred vision
• Greater role in COPD than in asthma
“Controller” Drugs:
Antiinflammatory
•
Inhaled corticosteroids
– Beclomethasone (Beclovent, Vanceril)
– Budesonide (Pulmicort)
(Turbuhaler, and Respules)
– Flunisolide (Aerobid, Aerobid M)
– Fluticasone (Flovent)
(Advair = combo with salmeterol)
– Triamcinolone (Azmacort)
• Important to note
– Low, intermediate, high dose
– dosage form and strengths
Non-Steroid “Controllers”
Antiinflammatory
•
Mast cell stabilizers
(inhaled: MDI or nebs)
– Cromolyn (Intal)
– Nedocromil (Tilade)
• Leukotriene modifiers
(Oral)
– Lipooxygenase inhibitor:
Zileuton (Zyflo)
– Receptor blockers:
Zafirlukast (Accolate)
Montelukast (Singulair)
Long acting
bronchodilators
•
Inhaled beta agonist
– Salmeterol (Serevent MDI and
Diskus)
– Formoterol (Foradil Aerolizer)
– Night time, exercise or adjunct to
anti-inflammatory drugs
•
Oral beta adrenergic agonists
– albuterol, metaproterenol,
terbutaline
– sustained release for night time
Proventil Repetabs, Volmax
– syrups for children (albuterol,
metaproterenol
Salmeterol (Serevent) Diskus
50 mcg/dose; 60 doses
Open door to
reveal mouthpiece
Slide lever.
“Click” indicates
dose in place.
Dose counter
advances.
Hold level to hold
powder in place.
Inhale quickly.
Close door to reset.
Long acting
bronchodilators (continued)
•
Theophylline
– rapid acting, sustained release
(many products recently removed
from the market)
– intravenous (aminophylline)
– Possibly mild anti-inflammatory
– Increased diaphragm contractility
(“diaphragmatic inotrope”)
– Primarily reserved for COPD
Other asthma
medications
•
•
•
•
•
Oral or injectable steroids
– Prednisone, prednisolone,
methylprednisolone
– “burst therapy” for rapid decline
– Emergency and hospital use
Methotrexate
Allergy desensitization
Soluble IL-4 receptor (IL4R) to bind
IL-4 and prevent binding of IL-4 to
tissue receptors.
3 mg Q week via inhalation
Olizumab: recombinant monoclonal
antibody to IgE
150-300 mg SC Q 2- 4 weeks
Therapeutic goals:
Individualize to patient
•
Minimal, infrequent episodes
– Freedom from symptoms;
Day and night.
•
•
Maintain normal activity
including exercise
Maintain best possible
pulmonary function
– Consider what is realistic
•
Prevent acute episodes
– < 3 beta agonist per week
– No emergency room visits or
hospitalizations.
Therapeutic goals (cont.)
•
•
•
•
Avoid medication adverse effects
Prevent asthma related death
Meet patient/family expectations
Patient/family education:
– symptoms
– triggers
– metered dose inhaler technique
(have patient demonstrate)
– “reliever” vs “controller” drugs
– peak flow meter monitoring
(Green, yellow and red zones)
Environmental Control
•
•
•
•
•
•
Same as for allergic rhinitis
Bedding
Carpets
Stuffed animals
Pets
Avoidance of allergens and
triggers
Step Approach to
Classification and Therapy
•
Mild Intermittent
– PRN bronchodilators
•
Mild Persistent
– Symptoms 3-6 times/ week
– Add antiinflammatory
•
Moderate Persistent
– Combinations of
antiinflammatories and
long acting bronchodilators
•
Severe Persistent
• Acute exacerbations
Staging:
Further Considerations
•
•
•
•
•
•
•
Seasonality
Nocturnal symptoms
Exercise induced
Peak flow monitoring
Daily fluctuations
Cough variant
“Wheezy bronchitis” in
children
COPD:
Chronic Obstructive
Pulmonary Disease
•
•
•
•
•
Any lung condition causing
longstanding airflow limitation with
impaired expiratory outflow…
…airflow obstruction due to chronic
bronchitis (and/or) emphysema
Generally progressive, may be
accompanied by airway
hyperreactivity, and may be partially
reversible
…caused by abnormal inflammatory
reaction to chronic inhalation of
particles
2-10% of US population over age 55
4th to 5th leading cause of death
Assessing Peak
Flow Rate
Pulmonary function:
Bronchodilator tone
•
Peak expiratory flow rate (PEFR) in
liters/ minute
• Forced expiratory volume in one
second (FEV1) in liters
• Normal values vary according to
sex, age, height
– Reported as absolute values or
– Percentage of normal or of
personal best
•
Establish patient zones
– Green = 80-100% of normal
– Yellow = 50-79% of normal
– Red = <50% of normal
Peak Expiratory Flow Rate
•
•
First blast of air exhaled by the
patient reaches this flow rate
almost immediately.
The flow rate quickly slows as
more air is exhaled.
– Less elastic recoil by lung
•
Indirect measure of lumen size
of large airways and strength of
expiratory muscles during
maximal effort.
True Zone Peak Flow Meter
Peak Flow Meter
Directions for use of
Peak Flow Meter
•
“zero the pointer”
– Move indicator to bottom of
numbered scale on meter.
•
•
•
Stand upright
Breathe in as deeply and
completely as possible
Close lips around mouthpiece to
form tight seal
– Do not put tongue in opening
•
•
Quickly blow out as hard and
fast as you can.
Note reading; repeat 3 times