Asthma Management for the PEBC Exam

This chapter is specifically designed for the PEBC (Pharmacy Examining Board of Canada) exam to help candidates understand the fundamentals of asthma management.

Introduction

Asthma is a chronic respiratory disorder characterized by the following key features:

• Symptoms: Patients experience episodic or persistent symptoms such as difficulty breathing (dyspnea), chest tightness, wheezing, sputum production, and cough.

• Variable Airflow Limitation: Airflow obstruction in the lungs that can fluctuate over time.

• Airway Inflammation: Chronic inflammation within the airways that contributes to symptoms.

• Airway Hyperresponsiveness: Heightened sensitivity of the airways, causing them to constrict more easily in response to various triggers.

According to the 2023 Global Initiative for Asthma (GINA) guidelines, asthma is a heterogeneous disease primarily defined by chronic airway inflammation that leads to airflow limitation. Patients often present with a combination of wheezing, shortness of breath, chest tightness, and cough. These symptoms can vary significantly over time and in severity, depending on the degree of airway inflammation and obstruction.

Goals of Asthma Control

The Global Initiative for Asthma (GINA) and the Canadian Thoracic Society (CTS) have outlined specific goals for effective asthma control:

• Symptom Frequency: Symptoms should occur fewer than 3 days per week.

• Reliever Use: Use of reliever medication (e.g., short-acting beta-agonists like salbutamol) should be limited to fewer than 3 doses per week.

Scope of the Chapter

This chapter covers the clinical presentation, diagnostic criteria, and treatment strategies for asthma, focusing on adolescents and adults. For management of asthma in younger patients (ages 13–17) who require caregiver supervision, refer to the section on Asthma in Infants and Children.

This structured approach to asthma management will assist PEBC candidates in understanding current best practices and clinical guidelines, with a focus on evidence-based strategies for optimizing asthma control and improving patient outcomes.

Goals of Therapy for Asthma

The primary goals in asthma management are focused on preventing complications, maintaining control, and optimizing treatment. These goals include:

1. Preventing Asthma-Related Mortality: Minimize the risk of severe, life-threatening asthma episodes.

2. Preventing Exacerbations: Reduce the frequency of asthma flare-ups or attacks.

3. Maintaining Asthma Control:

• Normal Activity Levels: Ensure patients can maintain regular daily activities, avoid absences from work or school, and exercise without limitations.

• Controlling Symptoms: Limit daytime symptoms (e.g., cough, wheeze, shortness of breath) to ≤ twice per week, and aim to eliminate nighttime symptoms like waking due to asthma.

• Minimizing Reliever Use: Aim to restrict the use of quick-relief (rescue) medications to ≤ twice per week.

4. Optimizing Pharmacotherapy: Provide effective asthma medications while minimizing side effects.

Diagnosis of Asthma

A comprehensive diagnosis is essential to confirm asthma, assess its severity, and guide treatment. Key diagnostic steps include:

1. Detailed Medical History:

• Family History: Look for a family history of asthma or allergic conditions (atopy).

• Symptoms: Assess the frequency, severity, and timing of symptoms. For instance, note if symptoms occur after exposure to triggers or differ between day and night.

• Symptom Patterns: Identify if symptoms follow a seasonal pattern, are present year-round, or vary throughout the day.

• Trigger Factors: Evaluate for potential triggers like environmental allergens, occupational exposures, smoke, certain medications (e.g., ASA or beta-blockers), preservatives (e.g., sulfites), viral infections, exercise, rhinitis, sinusitis, gastroesophageal reflux, obesity, and psychological factors (e.g., anxiety, depression).

• Previous Medical Interventions: Document any history of prednisone use, hospitalizations, emergency room visits, or intensive care admissions due to asthma.

2. Physical Examination:

• Signs of Asthma: Check for wheezing, nasal polyps, nasal congestion, or voice changes.

• Absence of Certain Findings: Ensure that signs like crepitations (crackling sounds in the lungs), unilateral wheeze, or fingernail clubbing are absent, as these may indicate other respiratory conditions.

3. Objective Measurements:

• Spirometry: This is the preferred diagnostic test for asthma, measuring lung function and showing reduced expiratory flow rates with reversibility after using a bronchodilator.

• Home Peak Flow Monitoring: Useful for diagnosing asthma in some cases and for monitoring severe asthma or patients with poor awareness of airway obstruction.

• Bronchoprovocation Challenge Test: Conducted in lung function labs, often using methacholine or histamine, to confirm asthma when the diagnosis is uncertain.

• Future Testing Options: Office-based mannitol challenge testing may become available as another diagnostic option.

• Additional Biomarkers:

• Blood Eosinophil Count: A high count may predict a good response to certain asthma treatments.

• FeNO (Fractional Exhaled Nitric Oxide): Elevated levels indicate airway inflammation.

• Serum IgE Levels: May help guide treatment, especially if allergy-related.

• Sputum Eosinophil Counts: Used in specialized centers to monitor response to anti-inflammatory therapy and adjust treatment in moderate to severe asthma.

Therapeutic Choices for Asthma Management

This guide provides an overview of nonpharmacologic and pharmacologic choices in asthma management, including specific medications, recommended doses, durations, and cautions based on current guidelines.

Nonpharmacologic Choices

1. Avoidance of Triggers:

• Identify and Avoid: Patients should avoid known asthma triggers like environmental allergens (e.g., pollen, pet dander) and occupational irritants.

2. Smoking and Vaping Cessation:

• Complete Cessation: Advise quitting smoking and vaping (not just tobacco) to improve asthma control. Also, avoid exposure to secondhand smoke.

3. Manage Comorbid Conditions:

• Obesity: Encourage healthy eating and weight loss strategies, both through diet and physical activity. Provide guidance on managing exercise-induced asthma symptoms with pre-exercise relievers.

• Other Comorbidities: Address chronic rhinosinusitis, gastroesophageal reflux (GERD), sleep apnea, anxiety, and depression to help reduce asthma symptoms.

4. Allergen Immunotherapy (Hyposensitization):

• Consider for Specific Allergies: Use immunotherapy as an adjunct for patients with a confirmed link between allergen exposure and asthma symptoms. Avoid in patients with poorly controlled asthma due to the risk of severe reactions.

5. Environmental Modifications:

• Air Purifiers: Although HEPA filters may reduce allergen levels, general use of home air purifiers lacks robust evidence for asthma control.

Pharmacologic Choices

Asthma Medication Strategy

• Initial Assessment: Tailor treatment to asthma severity and past treatment response.

• Review Every 3–6 Months: If asthma control is achieved, consider reducing therapy gradually (stepwise reduction).

• Inhaled Therapy: Inhaled medications are preferred as they deliver drugs directly to the lungs and reduce systemic side effects. Use metered dose inhalers (pMDIs), dry powder inhalers (DPIs), or soft-mist inhalers (SMIs) depending on patient preference and environmental considerations.

Medication Classes and Recommendations

1. Inhaled Corticosteroids (ICS)

• Medications: Beclomethasone, budesonide, ciclesonide, fluticasone furoate, fluticasone propionate, mometasone.

• Dosage:

• Mild Asthma: Use low-dose ICS or ICS/LABA (e.g., budesonide/formoterol) as both controller and reliever.

• Moderate to Severe Asthma: Daily low-dose ICS or ICS/LABA with as-needed ICS/formoterol for symptom relief.

• Side Effects: To reduce the risk of oral thrush, rinse the mouth after inhalation and consider using a spacer device.

• Special Notes: Beclomethasone and ciclesonide are prodrugs activated in the lungs, potentially minimizing side effects.

2. Short-Acting Beta2-Agonists (SABA)

• Medications: Salbutamol (albuterol), terbutaline.

• Role: Traditionally used for quick relief of asthma symptoms.

• Recommendation: Avoid SABA monotherapy due to increased risks of severe exacerbations. SABA should be combined with low-dose ICS.

• Special Notes: Avoid older agents like isoproterenol and epinephrine due to lower beta2-selectivity and higher risk of cardiac side effects.

3. Long-Acting Beta2-Agonists (LABA)

• Medications: Formoterol, salmeterol, vilanterol.

• Dosage:

• Formoterol: Rapid onset, used in combination with budesonide for both maintenance and rescue therapy.

• Salmeterol: Slower onset, not suitable for quick relief.

• Vilanterol: Used in combination inhalers (e.g., with fluticasone) for once-daily dosing.

• Guidance: LABAs should always be combined with ICS to prevent increased risk of asthma-related death.

• Combination Inhalers: ICS/LABA combinations improve adherence and prevent LABA monotherapy. Products include fluticasone/salmeterol (BID), fluticasone furoate/vilanterol (once daily), and budesonide/formoterol (for maintenance and rescue therapy).

4. Muscarinic Antagonists (Anticholinergics)

• Short-Acting: Ipratropium - Useful for acute exacerbations, especially in patients sensitive to beta2-agonists.

• Long-Acting: Tiotropium (once daily) - Beneficial for patients with symptomatic asthma despite ICS/LABA therapy.

• Usage: Effective add-on therapy for patients with beta-blocker–induced bronchospasm or those experiencing side effects from beta2-agonists.

5. Leukotriene Receptor Antagonists (LTRAs)

• Medications: Montelukast.

• Role: Anti-inflammatory; second-line monotherapy or add-on therapy for asthma control, especially useful in patients with concurrent allergic rhinitis.

• Warnings: Montelukast carries a risk of neuropsychiatric side effects (e.g., mood changes, suicidal thoughts).

• Usage: Not as effective as ICS but may benefit patients who cannot tolerate ICS or have specific allergy triggers.

6. Systemic Corticosteroids

• Medication: Prednisone.

• Dosage: 25–50 mg daily for 7–14 days during acute exacerbations.

• Guidance: Limit to short-term use due to significant side effects (e.g., weight gain, mood changes, hypertension) with long-term administration.

• Chronic Use: Rarely used for long-term control due to severe side effects; alternative treatments should be prioritized.

7. Biologic Therapy

• Medications: Omalizumab (IgE blocker), Mepolizumab, Benralizumab, Reslizumab (IL-5 inhibitors), Tezepelumab (TSLP inhibitor), Dupilumab (IL-4/IL-13 inhibitor).

• Indications: Severe asthma with specific biomarkers (e.g., high eosinophil count, IgE levels) and poor control on standard therapy.

• Administration: Subcutaneous injections every 2–8 weeks depending on the agent.

• Effectiveness: Biologics reduce exacerbations, improve lung function, and may reduce reliance on oral corticosteroids.

8. Triple Therapy (ICS/LABA/LAMA)

• Combination Inhalers: Mometasone/glycopyrronium/indacaterol, fluticasone/umeclidinium/vilanterol.

• Indications: Used for adults with asthma not controlled on ICS/LABA alone.

Other Inhaled and Oral Agents

• Mast Cell Stabilizers: Rarely used due to limited efficacy.

• Methylxanthines (e.g., theophylline): Limited use due to side effects (e.g., nausea, arrhythmias) and need for monitoring.

• Oral Beta2-Agonists: Less effective and more side effects than inhaled versions; not recommended.

• Immunotherapy: Sublingual and subcutaneous options available for allergic asthma, though risks include anaphylaxis.

Key Takeaways from 2019 GINA Guidelines

1. Avoid SABA Monotherapy: SABA monotherapy is discouraged due to an increased risk of exacerbations.

• Recommended Alternative: Low-dose budesonide/formoterol (ICS/LABA) is preferred for both daily control and as-needed relief for mild asthma.

2. ICS as Foundation: Inhaled corticosteroids remain the foundation of asthma treatment, with stepwise addition of LABA, LTRA, or LAMA based on severity.

3. Environmental Impact of Inhalers: Use DPIs or SMIs when possible to reduce environmental impact associated with pMDI propellants.

Prevention of Asthma Exacerbations

To prevent asthma exacerbations, it is essential to implement strategies such as vaccinations, correct inhaler techniques, and ensuring medication adherence. This guide provides details on recommended vaccines, inhaler optimization, and methods to improve adherence for individuals with asthma.

1. Influenza Vaccine

• Recommendation: Annual influenza vaccination is recommended for everyone over 6 months of age without contraindications, especially individuals with asthma who are at higher risk of complications from influenza.

• Benefits: Reduces the incidence of febrile illness and asthma exacerbations that may lead to urgent care visits or hospitalizations.

• Contraindications: The live-attenuated influenza vaccine (LAIV) is not recommended for:

• Pregnant individuals.

• Those with severe asthma (defined as needing high-dose inhaled corticosteroids, recent use of oral corticosteroids, active wheezing, or medical visits for wheezing within 7 days of vaccination).

• Why Use: Prevents flu-related complications, which can be more severe in asthma patients.

2. Pneumococcal Vaccine

• Vaccine Types in Canada:

• PNEU-C-13: 13-valent conjugate vaccine.

• PNEU-C-15: 15-valent conjugate vaccine.

• PNEU-C-20: 20-valent conjugate vaccine.

• PNEU-P-23: 23-valent polysaccharide vaccine.

• Recommendations:

• Adults: 1 dose of PNEU-P-23, especially for those with an asthma exacerbation requiring medical care in the past year. Some experts suggest a booster at age 65 (and at least 5 years after the initial dose), though evidence for this is mixed.

• Children 5–18 Years: 1 dose of PNEU-C-13, followed by 1 dose of PNEU-P-23 after eight weeks.

• Considerations:

• PNEU-C-13 may be beneficial for asthma patients at increased risk of pneumococcal illness, though it may not be covered by all provincial health plans.

• Administration Sequence: If both PNEU-C-13 and PNEU-P-23 are needed, give PNEU-C-13 first and wait at least 8 weeks before PNEU-P-23. If PNEU-P-23 is given first, delay PNEU-C-13 for 1 year.

• Why Use: Prevents pneumococcal infections that could worsen asthma or lead to severe respiratory complications.

3. COVID-19 Vaccine

• Recommendation: Asthma patients should stay up-to-date with COVID-19 vaccinations, including boosters.

• Benefits: While controlled mild to moderate asthma does not increase the risk of COVID-19–related death, individuals with severe asthma, especially those who have needed oral corticosteroids recently, are at higher risk of severe outcomes.

• Why Use: Reduces risk of severe COVID-19 complications, particularly in patients with more severe asthma.

4. RSV Vaccine

• Recommendation: Recommended for adults aged 60 and older, who are at higher risk for severe respiratory syncytial virus (RSV) infections.

• Why Use: Helps prevent RSV-related complications, which can be severe in older adults with asthma.

5. Other Vaccinations

• General Recommendation: Individuals with asthma should stay up-to-date on all age-appropriate vaccinations, such as Tdap (tetanus, diphtheria, pertussis), MMR (measles, mumps, rubella), and zoster (shingles), as they are at higher risk for complications from vaccine-preventable diseases.

• Why Use: Prevents hospitalizations and severe outcomes from other infections that can exacerbate asthma.

Additional Considerations for Asthma Management

6. Inhaler Technique

• Importance: Proper inhaler technique is crucial to ensure effective drug delivery and improve asthma control.

• Common Errors: Many patients make inhaler technique errors, which can worsen asthma control and increase the likelihood of hospitalizations.

• Best Practices:

• pMDI (Pressurized Metered-Dose Inhaler): Requires a slow, deep breath.

• DPI (Dry Powder Inhaler): Requires a quick, deep breath.

• Recommendation: Avoid prescribing different types of inhalers (e.g., pMDI and DPI) to reduce technique errors. Review inhaler technique at every visit, and provide educational resources like instructional videos.

• Why Optimize: Ensures that patients receive the full benefit of their inhaled medications and reduces the risk of exacerbations due to poor technique.

7. Medication Adherence

• Challenge: Adherence to inhaled corticosteroids (ICS) is often low after the first prescription, with refill adherence rates as low as 36%.

• Strategies to Improve Adherence:

• Integrated care programs and regular follow-ups can help improve adherence.

• Asthma education during routine visits can reinforce the importance of medication adherence.

• Asthma Educators: Certified Asthma Educators are available in Canada and provide structured education programs. Evidence shows that patients who participate in these programs have better asthma control and outcomes.

• Why Encourage: Consistent medication use is essential for controlling asthma symptoms and preventing exacerbations. Higher adherence leads to better overall asthma management and reduces the need for emergency care.

Step-Up and Step-Down Therapy for Asthma Management

1. Step-Up Therapy

• Purpose: Increase asthma treatment when current therapy does not provide adequate control after 6–12 weeks.

• Medication Adjustments:

• ICS/LABA: Step up from low-dose inhaled corticosteroids (ICS) to an ICS/long-acting beta2-agonist (LABA) combination.

• Example: Budesonide/formoterol 100–200 mcg twice daily.

• Add-on Options:

• LABA: Add salmeterol 50 mcg twice daily.

• LTRA: Montelukast 10 mg daily, useful if allergic rhinitis is present.

• LAMA: Tiotropium 1.25 mcg once daily as an add-on for patients with exacerbations.

• Theophylline: Limited use due to narrow therapeutic window; start with 200 mg daily, monitor blood levels.

• Biologic Therapies: For severe cases with eosinophilic asthma, consider biologics like omalizumab or mepolizumab.

• Considerations: Ensure confirmed diagnosis, check adherence, optimize inhaler technique, address comorbidities (e.g., GERD), and minimize exposure to triggers.

2. Step-Down Therapy

• Purpose: Reduce treatment when asthma control is well maintained to minimize medication use.

• Criteria for Step-Down: Stable control with no exacerbations, minimal symptoms, and normal lung function.

• Medication Adjustments:

• ICS Dose Reduction: Lower the dose by 25–50% every 3 months.

• Example: If on high-dose budesonide/formoterol 200/6 mcg twice daily, reduce to 100/6 mcg.

• Bronchodilator Reduction: Gradually reduce the use of LABA or LAMA if stable.

• Cautions: Avoid complete discontinuation of ICS as this can lead to worsening asthma. Monitor closely during each step-down phase.

Asthma Action Plans

Purpose: A written action plan helps patients manage their symptoms and take appropriate action when asthma worsens.

Components:

• Medication Instructions: Include specific guidance on when to increase reliever (e.g., SABA) and controller (e.g., ICS) medications.

• Oral Corticosteroid (OCS) Use: Provide instructions for initiating OCS (e.g., prednisone 25–50 mg daily for 5–7 days) during exacerbations.

• When to Seek Medical Attention: Indications for seeking help, such as persistent symptoms or peak expiratory flow (PEF) drop >20% for over 2 days.

ICS Dosage Increase:

• The Canadian Thoracic Society suggests a temporary 4-fold increase in ICS for patients with a recent history of exacerbations.

• Example: Increase from budesonide 200 mcg to 800 mcg daily for 7–14 days.

• Limitations: This strategy has mixed evidence and may not benefit younger children.

Emergency Treatment of Asthma

1. Oxygenation

• Maintain oxygen saturation at 93–95% using pulse oximetry. Over-oxygenation is unnecessary.

2. Bronchodilation

• Inhaler with Spacer: Preferred for effective delivery, equivalent to nebulization.

• SABA + SAMA Combination: Ipratropium bromide (SAMA) with salbutamol (SABA) for severe exacerbations.

• Example: Ipratropium/salbutamol 0.5/2.5 mg nebulized every 20 minutes.

• Side Effects: Monitor for tremors, palpitations, and agitation.

3. Systemic Corticosteroids (OCS)

• Initiate Early: Prednisone 25–50 mg orally within 1 hour of presentation.

• When to Use: If symptoms persist despite SABA, if OCS was used within 3 months, or for patients with frequent exacerbations.

4. Avoidance of Antibiotics

• Empiric antibiotic use is generally discouraged as it does not shorten recovery time unless an infection is confirmed.

5. IV Therapy Options (for severe cases)

• Magnesium Sulfate: 2 g IV over 20 minutes for adults with FEV1 <25–35% or hypoxemia.

• Avoid Aminophylline: Due to potential side effects and limited benefit during initial treatment hours.

Special Populations and Unique Considerations

1. Adolescents

• Challenges: Adherence issues due to social stigma, forgetfulness, and introduction of substances like tobacco or cannabis.

• Strategies: Simplify regimens, reinforce education, switch from SABA to ICS/formoterol (PRN), and assess for mental health concerns.

2. Asthma with COPD Overlap

• Treatment: Combination of ICS/LABA ± LAMA tailored to symptoms and lung function. Follow COPD and asthma guidelines for best management practices.

3. Pregnancy and Asthma

• Treatment Goals: Maintain optimal asthma control to avoid poor pregnancy outcomes (e.g., preterm birth).

• Safe Medications: Budesonide (ICS) and short-acting beta2-agonists are preferred. Avoid theophylline if possible due to side effects.

• Biologics: Limited data on safety; weigh benefits against potential risks.

4. Breastfeeding

• Safe Options: Most bronchodilators and corticosteroids (inhaled or oral) are considered safe. Montelukast is transferred into breast milk but is approved for young children.

• Biologics: Lack of data; consider risks versus benefits of therapy.

Notes

1. Avoid Certain Medications:

• Aspirin & NSAIDs: Can trigger asthma in aspirin-sensitive patients; use with caution in high-risk individuals.

• Beta-Blockers: Avoid unless necessary; can worsen asthma.

2. Address Comorbidities:

• Conditions: GERD, obesity, anxiety, and rhinitis can worsen asthma control if untreated.

3. Patient Education:

• Inhaler Technique: Regularly review technique to prevent errors.

• Action Plan: Provide a written plan for symptom management, accessible through resources like the Canadian Lung Association or Family Physician Airways Group of Canada.

4. Vaccinations:

• Ensure patients are current with vaccines, including influenza, COVID-19, and RSV, to reduce infection-related exacerbations.