Combination Therapy for Respiratory Diseases

Evidence for Combination Therapy

The American College of Chest Physicians and Canadian Thoracic Society guidelines recommend combining inhaled corticosteroids like budesonide with long-acting bronchodilators for patients with moderate to severe COPD, improving lung function, symptoms, and quality of life 1, 2
Each agent (inhaled corticosteroids, long-acting β-agonists, and long-acting muscarinic antagonists), whether used alone or in combination, improves lung function, relieves symptoms, and enhances health-related quality of life in patients with COPD 1
For patients with COPD categories C and D, GOLD guidelines recommend combination therapy with an inhaled corticosteroid plus a long-acting β-agonist to reduce exacerbations and improve symptoms 1, 2
A Cochrane meta-analysis of 14 studies (11,794 patients) found that budesonide plus formoterol combinations reduced exacerbations, improved lung function, quality of life, and dyspnea compared to bronchodilator monotherapy in patients with COPD 1, 2

The Canadian Thoracic Society recommends LAMA/LABA/ICS triple therapy over dual therapy due to greater reduction in mortality, improved lung function, and better quality of life in patients with severe COPD 3
Start with combination therapy for patients with FEV₁ <80% predicted, moderate-to-high symptom burden, and history of exacerbations, as recommended by clinical guidelines 3
For patients with blood eosinophil counts ≥300 cells/mL, the addition of inhaled corticosteroids to bronchodilators is particularly beneficial in reducing inflammation and improving symptoms 3

There is a 4% increased risk of pneumonia with inhaled corticosteroid-containing regimens compared to bronchodilators alone, with a number needed to harm of 33 patients treated for one year 1, 2, 4
Monitor regularly for pneumonia, especially in patients who are current smokers, age ≥55 years, have prior exacerbations/pneumonia, BMI <25 kg/m², or severe airflow limitation 3, 4

The American Thoracic Society recommends combination therapy with budesonide and bronchodilators for patients with moderate to severe COPD, as it demonstrates incremental benefit compared to multiple-inhaler triple therapy 5

The ETHOS trial demonstrated that budesonide 320 mcg in triple combination therapy reduced exacerbations by 24% compared to LAMA/LABA alone, with a mortality benefit favoring the moderate dose 5
Single-inhaler triple therapy (containing budesonide, a long-acting beta-agonist, and a long-acting muscarinic antagonist) demonstrates incremental benefit compared to multiple-inhaler triple therapy, with a 24% lower annual rate of moderate or severe exacerbations compared with LAMA/LABA dual therapy 5

The ETHOS study showed no significant difference in exacerbation reduction between moderate (320 mcg) and low (160 mcg) dose budesonide, though mortality benefit favored the moderate dose 5
High doses of inhaled corticosteroids are not typically necessary—the dose-response curve is relatively flat, and higher doses increase adverse effects without proportional benefit 5

Never step down from triple therapy to dual therapy in patients at high risk of exacerbations—withdrawing inhaled corticosteroids increases the risk of moderate-severe exacerbations, particularly in patients with blood eosinophils ≥300 cells/mL 5
Do not use inhaled corticosteroids as monotherapy—they should only be used in combination with long-acting bronchodilators 5
Do not use systemic oral corticosteroids like prednisone for maintenance treatment 5

The Canadian Thoracic Society guidelines confirm that no significant difference in annual rate of moderate or severe exacerbations exists between LAMA/LABA/ICS groups with differing ICS doses, with a rate ratio of 1.00 (95% CI, 0.91-1.10) 6, 7
High doses of ICS are not typically necessary to achieve optimum benefit in COPD, as the dose-response curve is relatively flat 6
Both budesonide/formoterol and fluticasone/salmeterol combinations reduce moderate-to-severe exacerbations compared to monotherapy, with the number needed to treat being 4 patients for 1 year to prevent one moderate-to-severe exacerbation with triple therapy 6

In symptomatic patients with FEV1 <80% predicted, high symptom burden, and history of ≥2 moderate exacerbations or ≥1 severe exacerbation requiring hospitalization, initiate LAMA/LABA/ICS triple therapy 6, 8
Budesonide 160 mcg in triple combination therapy is sufficient—the ETHOS trial showed no significant difference in exacerbation reduction between 160 mg and 320 mg doses (rate ratio 1.00; 95% CI, 0.91-1.10) 6, 7
Single-inhaler triple therapy demonstrates incremental benefit compared to multiple-inhaler triple therapy 6

The number needed to harm is 33 patients treated for 1 year to cause one pneumonia with ICS-containing regimens, while the number needed to treat is 4 patients for 1 year to prevent one moderate-to-severe exacerbation 6
Advise patients to rinse mouth with water without swallowing after inhalation to reduce risk of oral candidiasis 9

Never use ICS monotherapy in COPD—ICS should only be used in combination with long-acting bronchodilators 6
Do not step down from triple therapy to dual therapy in patients at high risk of exacerbations—withdrawing ICS increases moderate-severe exacerbation risk, particularly in those with blood eosinophils ≥300 cells/μL 6, 7
Do not use systemic oral corticosteroids like prednisone for maintenance treatment in COPD 6