Asthma Pharmacotherapy Flashcards
Asthma stats
1/11 US kids has asthma
1/12 US adults has asthma
Females>males
Young>old
Black children>white children
Low education/income>high ed/income
Asthma Characteristics
* Chronic inflammatory disorder of the airway
* many cells and cellular components play a role (mast cells, eosinophils, neutrophils, macrophages, epithelial cells)
* Inflammation leads to recurrent episodes of cough, wheezing, breathlessness, chest tightness
* Widespread, variable, reversible airflow obstruction
Pathophysiology of asthma
* Bronchoconstriction
* Airway hyperreactivity
* Edema
* airway obstruction/inflammation
Symptoms of Asthma
* wheezing
* cough
* difficulty breathing/SOB
* chest tightness
* worse sx @ night or certain situations
* exercise, viral infection, allergens, irritants, weather changes, emotions, stress, menstrual
Medical history
- -symptoms -pattern of symptoms
- -development of disease and treatment
- -family history
- -social history
- -history of exacerbations
- -impact of asthma on patient & family
- -assessment of patient perceptions of disease
- -precipitating and/or aggravating factors
Asthma Triggers
* Respiratory infections
* Environmental allergens (mold, house dust, cockroaches, animal dander, pollen)
* Smoking
* Exercise
* Occupational chemical
* Environmental changes
Physical Exam
Upper Respiratory tract
-increased nasal secretions, mucosal swelling, nasal polyps
Chest
-wheezing, hyperexpansion of thorax, use of accessory muscles (work hard to breathe)
Skin (atopic dermatitis, eczema)
Spirometry: FEV-1 & FVC
* FEV-1 = forced expiratory volume in 1 second
* FVC = forced vital capacity
* the amount of air which can be forcibly exhaled from the lungs after taking the deepest breath possible
Spirometry: FEV-1/FVC
FEV-1/FVC
* reduced in asthma ( 0.75-0.8 in adults and >0.9 in children
Spirometry: Positive bronchodilator reversibility test
increase from baseline in:
* FEV-1 > 200 mL
* FEV-1 increases > 12%
* after short acting beta agonist
* reversibility component is hallmark of asthma
Spirometry
* initial assessment
* after treatment has been started and symptoms have stabilized
* loss of asthma control
* every 1-2 years
Goals of Asthma Treatment
* Reduce impairment
-reduced symptoms, minimal need of rescue inhaler, few nighttime awakenings, optimal lung function, maintain normal daily activity
* Reduce Risk
-prevent exacerbations/need for hospitalization, prevent reduced lung growth in children/loss of lung fx in adults, optimize medications & minimize adverse effects
4 Components of Asthma Management
1) Assessment & monitoring
2) Medications (initiated based on severity, adjusted based on control)
3) Patient education
4) Control environmental factors & comorbid conditions
Routine Assessment/ Monitoring
1) Severity
- impairment, risk
2) Control
- impairment, risk
3) Responsiveness
- ease with which asthma control is achieved by therapy
Severity
* intensity of disease process
* used to initiate therapy
* severity is best measured in a patient NOT receiving long term control medication
* (ok if on SABA)
Assessment of Severity
* Impairment
-symptoms in the past week, nighttime awakenings, use of rescue medication, interference with physical activity, lung function
* Risk
-unexpected visits to doctor, emergency department, or hospitalizations
Medications: Quick relief medication
* Short acting beta agonists (SABAs)
* Short acting anticholinergics
* Systemic corticosteroids
Medications: Long term control meds
* Inhaled corticosteroids (ICS)
* Long acting beta agonists (LABAs)
* Cromolyn
* Leukotriene Modifiers
* Methylxanthines
* Immunomodulators
Asthma medication terminology
MDI = metered dose inhaler
HFA = hydrofluoroalkane (propellant)
DPI = dry powder inhaler
-spacer -nebulizer
Short acting beta-agonists (SABAs)
role in therapy:
- drug of choice for acute bronchospasm
- sole treatment for intermittent asthma
- therapy of choice for exercise induced bronchospasm (EIB) (Albuterol, Levalbuterol)
SABAs: adverse effects/ considerations
* Adverse effects :
- tachycardia, tremor, hypokalemia, hyperglycemia
- in general, inhaled route leads to few systemic side effects
* Therapeutic considerations:
-increase in use or lack of effect indicates diminished control of asthma, not for long term daily use, inhalation route is preferred, (some oral available), all patients with asthma should have SABA available
Anticholinergics
Role in therapy:
- drug of choice for bronchospasm due to beta-blocker medication
- alternative for patients intolerant to SABA
- used in combination w/ SABA during acute exacerbation (Ipatropium)
Anticholinergics: Adverse effects/ therapeutic considerations
* Adverse Effects:
- drying of mouth and respiratory secretions, blurred vision in eyes
- less cardiac stimulation than SABAs
* Therapeutic Considerations:
-increase in use or lack of effect indicates diminished control of asthma, not for long term daily use in asthma , does NOT work for EIB
Oral corticosteroids
role in therapy:
- short courses “bursts” used to establish control with initiation of therapy or during exacerbation
- may be used daily in severe persistent asthma (Methylprednisolone, Prednisolone, Prednisone)
Oral corticosteroids: adverse effects/ therapeutic considerations
* Adverse effects:
-short term use : glucose abnormalities, increased appetite, fluid retention, weight gain, facial flushing, mood changes, HTN, adrenal suppression, osteoporosis, skin thinning, growth suppression
* Therapeutic Considerations:
-burst should be continued until patient achieves 80% of peak expiratory flow or symptoms resolve, diff. doses for daily use, tapering ONLY w/ daily use
Inhaled corticosteroids
role in therapy:
-drug of choice for persistent asthma, long term prevention of symptoms, suppression, control, and reversal of inflammation (Beclomethasone, Budesonide, Flunisolide, Fluticasone, Mometasone, Triamcinolone)
ICS: Adverse effects/ therapeutic considerations
* Adverse effects:
- cough, dysphonia, oral thrush
- at high doses, systemic side effects may occur
* Therapeutic considerations:
- reduce risk of thrush by use of spacer /holding chamber with MDI and rinsing mouth afterwards
- Dexamethasone is not used as ICS due to high absorption and long term suppressive side effects
Long acting beta agonist (LABAs)
Role in therapy:
- long term prevention of symptoms in addition to ICS
- prevention of exercise induced bronchospasm - do NOT use for acute symptoms
- potential for uncommon, severe, life threatening, or fatal exacerbation when used as monotherapy in asthma (Salmeterol, Formoterol)
LABA: adverse effects/ therapeutic considerations
* Adverse effects :
- tachycardia, tremor, hypokalemia, prolongation of QTc
* Therapeutic considerations:
- do not use for acute symptoms, do not use as monotherapy , may provide more control when added to ICS compared to increasing dose ICS
Advair
fluticasone/salmeterol
Symbicort
budesonide/formoterol
Dulera
mometasone/ formoterol
Cromolyn
role in therapy:
- long term prevention of symptoms in mild persistent asthma as an alternative to ICS
- preventive treatment prior to exposure to exercise or known allergen (not good data for efficacy, dosed QID–not good for pt adherence, minimal adverse effects)
Cromolyn: adverse effects/therapeutic considerations
* Adverse effects :
- cough, irritation
* Therapeutic Considerations
- safety is primary advantage of Cromolyn
- therapeutic response will typically occur in 2 weeks, max benefit 4-6 weeks (takes awhile)
- dose of MDI cromolyn may be inadequate, nebulizer may be preferred
Leukotriene Modifiers
role in therapy:
- alternative treatment for persistent asthma
- may be used in EIB , aspirin-induced asthma , and allergic asthma
Leukotriene Modifiers
Montelukast (LTRA)
Zarfirlukast (LTRA)
Zilueton (5-lipoxygenase inhibitor)
Leukotriene Modifiers: adverse effects/ therapeutic considerations
* Adverse effects:
- LTRA: headache
- 5-lipo: GI upset, HA, hepatoxicity
* Therapeutic considerations :
-monitor liver fxn w/ Zafirlukast & Zileuton, admin. Zafirlukast 1 hr before or 2 hrs after meals, drug int. w/ Zafir/Zilue, approved allergic rhinitis
Methylxanthines (theophylline)
role in therapy :
-long term control/prevention of sx of mild persistent asthma (as an alternative to ICS) or adjunctive therapy w/ ICS in mod-severe asthma (cheap & effective)
Theophylline adverse effects
- insomnia, gastric upset, aggravation of ulcer/GERD, increase in hyperreactivity in kids
- toxicities : tachycardia, N/V, tachyarrhythimias, CNS stimulation, HA, seizures, hematemesis, hyperglycemia, hypokalemia
Theophylline therapeutic considerations
* regular serum monitoring is necessary
* narrow therapeutic window
* severe toxicity steady-state concentrations= 5-15mcg/mL food affects absorption many drug-drug/drug-disease interactions
Immunomodulators
role in therapy :
- long term control/prevention of sx in adults ( > 12yr) who have mod-severe persistent allergic asthma inadequately controlled w/ ICS (only step 5 & 6 > 12 yrs old)
- Omalizumab
Omalizumab: adverse effects/ therapeutic considerations
* Adverse effects :
-pain/bruising at injection sites, anaphylaxis
* Therapeutic considerations:
-monitor following injections due to potential for anaphylaxis, admin. no more than 150mg in one injection, refrigerate
Tiotropium in asthma
* Long acting anticholinergic bronchodilator
* widely used for COPD, not included in asthma guidelines
* clinical studies: 5-10 mcg dose studied in patients w/ asthma sx despite ICS/LABA, improved FEV-1 and PEF w/ addition of tiotropium
* Reserve for poorly controlled asthma despite ICS/LABA
Choosing btwn tx options
* Patient level choices
-preferred treatment, patient characteristics, patient preferences, practical issues (inhaler technique, cost, adherence)
* Population level choices -formulary restrictions
Environmental Factors
- Reducing exposure to irritants or allergens reduces inflammation, symptoms, and need for medication.
- Identify potential role of allergens
- Work together to determine ways to avoid allergens
Comorbid conditions
* tx of comorbid conditions that impede asthma mgmt may improve asthma control
* common comorbid conditions that may affect asthma:
-GERD, obesity, obstructive sleep apnea, stress, depression
Patient education topics
* basic facts about asthma
* role of medication -diff. btwn rescue/maintence inhalers
* patient skills -inhaler technique, environmental exposures, self-monitoring, asthma action plan
Patient education
* self-management education
-improves patient outcomes, cost-effective
* how to integrate self-management -
active partnership, written asthma plan, repetition
Asthma action plan
* instructions for daily management
-long term medication, environmental control measures
* how to manage worsening asthma
-signs/symptoms, medications to take
* typically recommended for patients with:
-mod-severe persistent asthma, severe exacerbations, poorly controlled asthma
Green zone
doing well
-no cough, wheeze, chest tightness, or SOB during the day or night -can do usual activities
Yellow zone
asthma is getting worse
- cough, wheeze, chest tightness, or SOB, or
- waking at night due to asthma, or
- can do some, but not all, usual activities
Red zone
medical alert!
- very SOB, or
- quick-relief medicine have not helped, or
- cannot do usual activities, or
- symptoms are same or get worse after 24 hours in yellow zones
Exacerbation
* episodes of progressively worsening SOB, cough, wheezing, and/or chest tightness
* decreased lung function
* “flare up” or “episode”
Increased risk of asthma-related death
- hx of near-fatal asthma requiring intubation
- hospitalization or ED visit for asthma in past year
- currently using or having recently stopped using oral corticosteroids
- not currently using ICS
- over use of SABAs
- hx of psychiatric disease or psychosocial problems
- poor adherence w/ asthma meds/action plan
- food allergy in patient w/ asthma
Management
- self management with asthma action plan
- primary care office
- emergency department
Primary Care management: mild-moderate
* Mild or Moderate:
- talks in phrases, prefers sitting to lying down, not agitated
- increased respiratory rate
- no use of accessory muscles
- pulse = 100-120 bpm
- O2 saturation 90-95% -PEF > 50% predicted/best
Primary care management: Severe
* Severe:
- talks in words, sits hunched forward, agitated
- RR > 30 breaths/min
- accessory muscles in use
- Pulse > 120 bpm
- O2 saturation
* Life-threatening : drowsy, confused, silent chest
Mild-moderate treatment of exacerbation
* SABA 4-10 puffs by MDI + spacer, repeat Q20 mins for 1 hour
* Prednisolone : -adults: 1mg/kg, max 50 mg -children: 1-2mg/kg, max 40 mg
* Controlled oxygen -target 93-95% in adults, 94-98% in children
* Assess response at 1 hour
Discharge from PCP
* Discharge if: -sx improved, PEF improving, O2 saturation >94% on room air, adequate resources at home
* Arrange at discharge:
-SABA, controller (check inhaler technique, assess adherence), Prednisolone (adults 5-7 days, kids 3-5 days), Follow up in 2-7 days
Severe/Life threatening exacerbation
* transfer to acute care facility
* while waiting give:
* SABA * Oxygen * Systemic corticosteroids
Emergency department Management
* Assess: A irway, B reathing, C irculation
* if drowsiness, confusion, silent chest are present ⇒ transfer to Intensive Care Unit
* if above symptoms are not present:
* classify as mild/moderate vs. severe
ED management
* Mild/moderate
-SABA, consider Ipatropium, Oxygen, oral corticosteroids
* Severe -SABA, Ipatropium, Oxygen, oral or IV corticosteroids, consider IV magnesium, consider high dose ICS
Reassessment in ED
* measure lung function in all patients after 1 hour
* If FEV-1 or PEF is 60-80% of predicted or personal best AND symptoms have improved ⇒ consider discharge planning
* If FEV-1 or PEF <60% of predicted or personal best OR lack of clinical response ⇒ continue treatment and reassess frequently
Exercise induced bronchospasm (EIB)
- asthma symptoms occurring during or after exercise - warm up period before exercise
- if symptoms are only during/after exercise:
* SABA (tolerance may develop w/ regular use) or
* LTRA or Cromolyn
*if symptoms occur unrelated to exercise or risk of exacerbation: ICS or LTRA
Pregnancy
1:1:1 = ratio of patients whose asthma improves, worsens, and does not change during pregnancy -poor control can lead to worse outcomes for baby & mother
* Albuterol = rescue drug of choice *
Budesonide = control drug of choice/ICS of choice
* Formoterol = LABA of choice
* Ok to keep pt on ICS/LABA if well controlled
