According to results of the AMAZES study, treatment with azithromycin over 48 weeks not only reduces the rate of asthma exacerbations, but also increases quality of life in patients with persistent asthma compared to placebo.

• Double-blind, placebo-controlled, parallel-group study evaluated the safety and efficacy of azithromycin “as add-on therapy in patients with uncontrolled persistent asthma on medium-to-high dose inhaled corticosteroids plus a long-acting bronchodilator”
• 420 patients were randomized (1:1) to receive 500mg oral azithromycin (n=213) or placebo (n=207) administered three times each week for 48 weeks
• Study excluded patients with hearing impairments or abnormal QT interval prolongation
• Primary endpoint: total rate of asthma exacerbations during the study period (moderate and severe), asthma quality of life
• Utilized an intention-to-treat analysis

• Asthma exacerbations: 1.07 per patient-year for azithromycin patients (95% CI: 0.85, 1.29) vs 1.86 per patient-year for placebo patients (95% CI: 1.54, 2.18) (incidence rate ratio: 0.59; 95% CI: 0.47, 0.74; P<0.0001)
• 44% of azithromycin patients experienced ≥1 asthma exacerbation vs 61% of placebo patients (P<0.0001)
• Asthma-related quality of life: significantly improved in patients who received azithromycin (adjusted mean difference: 0.36; 95% CI: 0.21, 0.52; P=0.001)
• The most common adverse event reported was diarrhea, which was experienced by 34% of azithromycin patients vs 19% of placebo patients (P=0.001)