What are the differences in treatment between Chronic Obstructive Pulmonary Disease (COPD) and asthma?

COPD vs Asthma: Key Treatment Differences

Start with inhaled corticosteroids (ICS) as first-line controller therapy for asthma, but use long-acting bronchodilators (LAMA or LABA) as first-line therapy for COPD—this fundamental difference in initial treatment reflects the reversible inflammatory nature of asthma versus the largely irreversible airflow limitation in COPD. 1, 2

Diagnostic Differentiation Drives Treatment

COPD Diagnosis

• Confirm with post-bronchodilator spirometry showing FEV1/FVC <0.70 with minimal reversibility (<10% predicted improvement or <12% and <200 mL change in FEV1) 2, 3
• Typically occurs in patients >40 years with significant smoking history (≥10 pack-years) or occupational exposures 2
• Symptoms worsen gradually over time rather than episodically 2

Asthma Diagnosis

• Requires significant reversibility (>10% predicted improvement) with bronchodilators, or peak flow variability >15% over 2 weeks 4, 2
• Alternatively, bronchial challenge test showing PC20 <2 mg/mL histamine or methacholine confirms diagnosis 4
• Often begins in childhood or adolescence, associated with atopy and allergic conditions 1, 2

COPD Treatment Algorithm

Mild COPD (FEV1 ≥70% predicted)

• Start with LAMA or LABA monotherapy as first-line treatment 1, 2
• Examples include tiotropium (LAMA) or salmeterol (LABA) 4, 5

Moderate to Severe COPD

• Add a second long-acting bronchodilator (LAMA + LABA combination) if symptoms persist on monotherapy 1
• Add ICS only if the patient has frequent exacerbations despite optimal bronchodilator therapy, blood or sputum eosinophilia (≥3%), or features of asthma-COPD overlap 1, 6
• This is critical: approximately 20-30% of COPD patients with elevated eosinophils respond better to ICS therapy 6

Alternative Therapies for COPD

• Consider theophylline (adjusted to peak serum level 5-15 μg/L) if bronchodilators are insufficient 4
• If theophylline not tolerated, use long-acting oral or inhaled β2-agonists 4

Asthma Treatment Algorithm

First-Line Asthma Treatment

• Start with low-dose ICS as controller medication for all persistent asthma 1, 2
• Provide short-acting beta-agonists (SABA) as needed for symptom relief 1

Step-Up Therapy for Asthma

• Add LABA to ICS (ICS/LABA combination) if symptoms persist on ICS alone 1
• Consider higher dose ICS or add-on therapies (leukotriene modifiers, tiotropium) for difficult-to-control asthma 1
• Adjust ICS dose based on symptom control and exacerbation frequency 1

Asthma-COPD Overlap: Special Considerations

Diagnostic Criteria for Overlap

• Post-bronchodilator FEV1/FVC <0.70 (persistent airflow limitation) PLUS significant bronchodilator reversibility (≥12% and ≥200 mL improvement in FEV1) 1, 3
• Approximately 20% of patients with obstructive airway disease have features of both conditions 4, 6
• These patients have increased morbidity, more frequent exacerbations, and possibly higher mortality (HR 1.45) compared to COPD alone (HR 1.28) or asthma alone (HR 1.04) 4, 6

Treatment for Overlap

• Start with ICS/LABA combination therapy as first-line treatment—this is mandatory, not optional 1, 2
• Add LAMA (triple therapy: ICS/LABA/LAMA) if symptoms persist or exacerbations continue 1
• The ICS component is essential because these patients have features of asthma and require anti-inflammatory therapy 1

Critical Monitoring Parameters

For All Patients

• Check medication dose, frequency, and inhaler technique at every visit 4, 2
• Assess symptom relief and reinforce smoking cessation 4
• Measure FEV1 and vital capacity regularly to monitor disease progression 4, 2

COPD-Specific Monitoring

• Monitor for pneumonia risk, especially in patients on ICS (increased risk in COPD) 5
• Assess for fast decline in FEV1 (>50 mL/year), which indicates need for ICS consideration 4
• Evaluate exercise capacity and respiratory muscle function to identify candidates for pulmonary rehabilitation 4

Asthma-Specific Monitoring

• Monitor peak flow variability and symptom patterns 4
• Assess for triggers and allergen exposures 2

Important Caveats and Pitfalls

Common Prescribing Errors

• Never use LABA monotherapy in asthma—it increases risk of serious asthma-related events and death 5
• Do not combine Wixela Inhub (or similar ICS/LABA products) with additional LABA-containing medications due to overdose risk 5
• Avoid initiating ICS/LABA in acutely deteriorating asthma or COPD; these are not for acute symptom relief 5

Long-term ICS Risks

• Monitor for oral candidiasis—advise patients to rinse mouth with water after inhalation 5
• Assess bone mineral density initially and periodically, especially with high-dose ICS (≥1,000 μg/day) 4, 5
• Monitor pediatric growth in children on ICS 5
• Screen for glaucoma and cataracts with long-term use 5
• If using oral corticosteroids long-term, provide osteoporosis protection (calcium, vitamin D, bisphosphonates) 4

Inflammatory Pattern Considerations

• COPD primarily shows neutrophilic inflammation, while asthma typically shows eosinophilic inflammation 6
• However, both diseases can exhibit heterogeneous patterns—approximately 20-30% of COPD patients have eosinophilic inflammation and may benefit from ICS 6
• Overlap patients show mixed patterns: 35% eosinophilic, 19% neutrophilic, 10% mixed inflammatory pattern 6

Device and Dosing Specifics

• For high-dose ICS (≥1,000 μg/day), use large-volume spacer or dry-powder system 4
• Objective response to therapy is defined as FEV1 improvement ≥10% predicted and/or >200 mL 4