Study objectives: To investigate whether erythromycin therapy lowers the frequency of the common cold and subsequent exacerbation in patients with COPD.
Design: Prospective, randomized, controlled, but not blinded, trial.
Patients: One hundred nine patients with COPD were enrolled into the study. Patients were randomly assigned to erythromycin therapy or to no active treatment in September 1997. Patients then were observed for 12 months, starting in October, during which time the risk and frequency of catching common colds and COPD exacerbations were investigated. Fifty-five patients received erythromycin at study entry (erythromycin group). The remaining 54 patients received no active treatment (control group).
Measurements and results: The mean (+/- SE) number of common colds for 12 months was significantly lower in the erythromycin group than in the control group (1.24 +/- 0.07 vs 4.54 +/- 0.02, respectively, per person; p = 0.0002). Forty-one patients (76%) in the control group experienced common colds more than once, compared to 7 patients (13%) in the erythromycin group. The relative risk of developing two or more common colds in the control group compared with that in the erythromycin group was 9.26 (95% confidence interval [CI], 3.92 to 31.74; p = 0.0001). Thirty patients (56%) in the control group and 6 patients (11%) in the erythromycin group had one or more exacerbations. The relative risk of experiencing an exacerbation in the control group compared with that in the erythromycin group was 4.71 (95% CI, 1.53 to 14.5; p = 0.007). Significantly more patients were hospitalized due to exacerbations in the control group than in the erythromycin group (p = 0.0007).
Conclusion: Erythromycin therapy has beneficial effects on the prevention of exacerbations in COPD patients.