For individuals with uncontrolled asthma, the risk of asthma attacks or exacerbations is a constant concern. A recent clinical trial reported a significant reduction in the rate of asthma exacerbation in patients treated with azithromycin.
It is estimated that over 50 million people around the world suffer from moderate to severe uncontrolled asthma. Chronic airway inflammation and an increased susceptibility to respiratory infections place a high burden on patients who must seek immediate medical attention when experiencing asthma exacerbations or attacks. Although inhaled corticosteroids and bronchodilators are commonly used to manage asthma, they are not enough to prevent exacerbations. For patients with moderate to severe uncontrolled asthma, there is a need for additional treatment.
Macrolide antibiotics such as azithromycin have broad antibacterial, antiviral, and anti-inflammatory properties. Previous systematic reviews report that macrolides can alleviate asthma symptoms, but their effect on the rate of exacerbations is not well known. A research team in Australia carried out a randomized clinical trial to determine whether azithromycin can reduce the rate of asthma exacerbations in patients who are currently on inhaled corticosteroid and bronchodilator therapy.
Their study, published in The Lancet, employed a multicenter, randomized, double-blind, placebo-controlled, parallel group design. Clinically stable non-smoking adults with a history of uncontrolled symptomatic asthma were recruited into the study. After randomization to either the placebo group or azithromycin group, patients were treated for a period of 48 weeks. Patients took either 500 mg oral azithromycin or placebo three times weekly in addition to their inhaled corticosteroid and bronchodilator medications. Follow-up assessments were carried out at weeks 6, 12, 24, 36, 48, and 52.
The primary outcomes measured were the total number of exacerbations over the 48 week period. Asthma exacerbations were well defined according to severity but generally involved a worsening of symptoms requiring increased corticosteroid therapy or hospitalizations and emergency room visits. Other measured outcomes included asthma control and quality of life questionnaires such as ACQ6 and AQLQ, lung function, microbial assessments, and adverse events.
A total of 334 patients completed the trial. The azithromycin group showed a significant reduction of asthma exacerbations compared to the placebo group, with an average of 1.86 exacerbations per person per year compared to 1.07 respectively. For patients in the placebo group, 61% experienced at least one asthma exacerbation compared to only 44% in the azithromycin group. Patients treated with azithromycin also showed improvement in the quality of life questionnaire scores. There was no significant difference between the two groups with regards to serious adverse events.
This study suggests that oral azithromycin can help lower the frequency of asthma exacerbations and improve quality of life in patients undergoing inhaled corticosteroid and bronchodilator therapy. The authors claim azithromycin therapy as a valuable new tool to add to the current repertoire of asthma treatments.
Written by Agustin Dominguez Iino, BSc
Gibson PG et al. Effect of azithromycin on asthma exacerbations and quality of life in adults with persistent uncontrolled asthma (AMAZES): a randomised, double-blind, placebo-controlled trial. The Lancet. 2017July 4. doi: http://dx.doi.org/10.1016/S0140-6736(17)31281-3