Macrolides May Help Asthma Patients Battle Chronic Cough

Greater than 10% of referrals to respiratory specialists are for chronic cough, given the condition’s persistent, refractory nature.

Chronic cough, which is a cough lasting longer than 8 weeks, adversely affects patients' quality of life and is often described as nagging or hacking in nature. Asthma, gastroesophageal reflux disease (GERD), and rhinitis are common noninfectious triggers of chronic cough, yet clinicians can find no known etiology in 20% of cases.

However, researchers know a few things about chronic cough. For instance, patients with chronic cough usually have elevated neutrophil counts.

By nature of their ability to suppress neutrophils, macrolides have anti-inflammatory properties independent of their antibacterial effects. In light of this, a recent article published in the journal Chest indicated that the macrolide azithromycin could clinically improve chronic cough.

The study authors conducted a randomized, double-blind, placebo-controlled trial in which 44 participants with chronic and longstanding cough received 250 mg azithromycin 3 times daily for 8 weeks. The study authors used the Leicester Cough Questionnaire to measure the enrolled participants’ clinical responses.

In most participants, clinically relevant and statistically significant improvement in the questionnaire scores occurred within the first 4 weeks, but overall, it was statistically insignificant. The study authors discovered greater improvement in patients with comorbid asthma (a neutrophilic disorder) and suggested that macrolides may have a place in treatment for these patients.

Those with asthma had failed to improve previously, despite changes in their regular asthma medication, a trial of prednisolone, and empirical treatment with non-macrolide antibiotics. In these patients, macrolides may correct the imbalance in airway bacterial flora caused by inhaled corticosteroid use, the researchers hypothesized.

Their study has strong external validity because they included patients with asthma, GERD, and rhinitis. The study authors maintained that their findings do not support the broad use of macrolides, but further study in asthma patients is worthwhile.