Physicians who prescribe long-term azithromycin should instruct patients to report any hearing loss.
Drug–drug interactions. Azithromycin is free of the drug–drug interactions characteristic of conventional macrolides, such as clarithromycin.40 Nevertheless:
Caution is advised when giving azithromycin in conjunction with coumadin or theophylline.
Giving azithromycin with antacids that contain aluminum or magnesium salts can reduce the rate, although not the extent, of the absorption of azithromycin.
The serum concentration of azithromycin is markedly increased when it is given with nelfinavir.40
Microbiome effects. The host microbiome can have a significant effect on the risk of asthma.2 A cross-sectional study indicated that lower respiratory bacterial burden is greater in patients with asthma, compared with that of healthy control subjects, and correlates with bronchial hyperresponsiveness.41 Early colonization of the infant nasopharynx, particularly with Streptococcus spp, is a predictor of asthma risk.42,43 Bacterial pathogens in the nasopharyngeal biome at the time of upper respiratory viral infection are significant determinants of risk for the spread of infection to the lower airways, suggesting that these microorganisms contribute to the risk of persistent asthma.41
In the long run, azithromycin was 10 to 20 times as cost effective as the other 3 therapeutic options for improving asthma qualityof-life outcomes.
Investigators have speculated that, rather than increasing the risk of asthma by disrupting the “healthy” microbiome, azithromycin might be helpful in treating an “unhealthy” microbiome.42,43 Recently, it was shown in a randomized trial that azithromycin induced a perturbation in the gut microbiota of children 14 days after randomization, although the drug did not have a long-lasting effect on the composition of gut microbiota.44
Consider a trial of azithromycin for patients who have new-onset asthma.
What about cost?
Inhaled corticosteroids and combination formulations of an ICS and a LABA are expensive and must be taken for the long term. A 3-month course of generic azithromycin—comparable to what was used in the OL subgroup of AZMATICS15—costs about as much as 1 ICS and LABA combination inhaler. Using published results,15,45 a pilot cost-effectiveness analysis in patients with persistent asthma compared doubling the ICS dosage, adding salmeterol, adding tiotropium, or prescribing 3 months of azithromycin. In the long run, azithromycin was 10 to 20 times as cost-effective as the other 3 therapeutic options for improving asthma quality-of-life outcomes.* However, reliable cost-effectiveness analyses require more, and better, evidence.
Continue to: Recommendations to reflect on for your practice
