Late Breaking Abstract - Prolonged azithromycin maintenance treatment in patients with COPD, a follow-up of the COLUMBUS trial

Introduction: Azithromycin maintenance therapy during one year resulted in a significant lower number of exacerbations as has been shown in the Columbus study. The aim of our current study is to investigate whether azithromycin treatment given for more than one year is equal effective in reducing exacerbation frequency. Method: This was a retrospective cohort study using data from the Columbus Trial cohort (N=92). In this study we compared data of patients still receiving macrolide treatment after finishing the Columbus trial with patients who stopped azithromycin treatment. In this population, we analyzed the number of exacerbations, time to first exacerbation and number of hospitalizations during one year after the Columbus trial. Results: Forty-one patients received macrolide treatment in the Columbus trial, of these 14 (34%) continued azithromycin treatment in the year after the Columbus trial. The exacerbation frequency in the maintenance group was not significantly higher (2.29 ±2.43) than in the non-maintenance group (1.67 ±1.69) p-value= 0.577. Also there was no significant difference in time-to-first exacerbation for the maintenance group compared to the non-maintenance group (respectively, 117 versus 164 days, p=0.11). The number of hospital admissions in the maintenance group versus the non-maintenance group was 0.56 ± 0.93 versus 1.36 ±1.91 respectively, not significant p=0.307. Conclusion: This is the first study which analyzed the long-term effect of azithromycin in COPD patients. Our data suggest that prolonged treatment with azithromycin for more than 1 year results in no further beneficial effect.