The efficacy and safety of long-term add-on treatment of azithromycin in asthma: A systematic review and meta-analysis

AIM: Effects of azithromycin on asthma reported in clinical trials are less consistent. We aimed to further clarify the efficacy and safety of azithromycin in treatment of asthma. METHODS: The protocol registration number was CRD42017074318 (http://www.crd.york.ac.uk/Prospero). We searched PubMed, EMBASE, Cochrane databases, China National Knowledge Internet (CNKI), and Wanfang databases for the randomized controlled trials (RCTs) with prolonged treatment of azithromycin for more than 3 weeks. Random-effects or fixed-effects model was applied to calculate risk ratio (RR) and mean difference (MD) for dichotomous and continuous data respectively. RESULTS: A total of eight studies were included for analysis. The pooled result of adjunctive azithromycin therapy in asthma showed a small, but statistically significant increase in forced expiratory volume in one second (FEV(1)) (MD = 0.06, 95% confidence interval [CI]: 0.01–0.12, P = .02), but no significant differences in exacerbation frequency (MD = −0.42, 95%CI: −1.13 to 0.30, P = .25) and peak expiratory flow (PEF) (MD = 0.20, 95% CI: −0.05 to 0.44, P = .12), fractional exhaled nitric oxide (FeNO) (MD = 4.12, 95% CI: −2.06 to 10.30, P = .19), asthma quality of life questionnaire (AQLQ) (MD: 0.05, 95% CI: −0.17 to 0.28, P = .65), asthma control questionnaire (ACQ) (MD: −0.03, 95% CI: −0.21 to 0.15, P = .75). The subgroup analysis revealed that azithromycin could decrease FeNO among Asian asthma (MD = 15.04, 95% CI: 6.18–23.90, P = .0009). CONCLUSIONS: Add-on therapy of azithromycin in asthma patients could improve the FEV(1), but failed to improve asthma exacerbations, PEF, ACQ, AQLQ, and FeNO. Subgroup analysis indicated that azithromycin could improve FeNO in Asian group asthmatics.