A Cochrane review of available data has concluded that there is considerable uncertainty around the effects of different prophylactic antibiotics in the management of COPD.
The review, carried out by researchers at the University of London, analysed data from two randomised clinical trials (RCTs), both published in 2015, involving a total of 391 participants, with treatment duration of 12 to 13 weeks.
One RCT compared a quinolone (moxifloxacin pulsed for 5 days every 4 weeks), with a tetracycline (doxycycline continuous) or a macrolide (azithromycin intermittent); the second compared a tetracycline (doxycycline continuous) plus a macrolide (roxithromycin continuous), with roxithromycin (continuous) alone.
There was no clear difference in improvement in quality of life as assessed by the Chronic Respiratory Questionnaire between macrolide + tetracycline versus macrolide.
For serious adverse events, it was uncertain if there was a difference between combined roxithromycin and doxycycline versus roxithromycin alone at 48 weeks of follow-up. At the same timepoint, five deaths had been reported in the combined treatment arm, versus three in the single treatment arm.
There was no clear difference for the number of participants experiencing one or more exacerbations at 13 weeks between moxifloxacin and doxycycline, moxifloxacin and azithromycin and azithromycin and doxycycline. There were no serious adverse events or deaths reported in any of these treatment groups.
Previous studies have shown a reduction of exacerbations with antibiotics in comparison to placebo in people with COPD, but there are concerns about antibiotic resistance and safety. However, this review could not find any head-to-head evidence for the impact of antibiotics on drug resistance.
The authors stress that the evidence is of very low certainty.