Physicians should also note the landmark trial of azithromycin in severe, smoking-associated COPD, which found a clinically significant benefit in reducing exacerbations and improving quality of life (NNT = 3, to prevent 1 exacerbation).18
Case series. In a prospective case series (Level 2 study: prospective cohort), 163 primary care outpatients (adolescents and adults) who had acute wheezing illnesses or chronic asthma were evaluated for C pneumoniae infection by serologic testing.19 A subgroup of this cohort also had nasopharyngeal cultures tested for C pneumoniae.
Rather than increasing the risk of asthma by disrupting the “healthy” microbiome, azithromycin might be helpful in treating an “unhealthy” microbiome.
Twenty patients (12%) were given a diagnosis of C pneumoniae infection defined by serology (n = 15), culture isolation (n = 3), or both (n = 2). Of the 20, 10 wheezed for the first time—6 of whom subsequently developed chronic asthma (n = 5) or chronic bronchitis (n = 1), with a serologic profile suggesting chronic infection. The other 10 patients who had a diagnosis of C pneumoniae infection already had a diagnosis of chronic asthma. In patients with established chronic asthma, initial serologic findings suggested chronic, rather than acute, C pneumoniae infection.
Tx recommendations: When to consider azithromycin
Randomized7 and nonrandomized15 evidence supports treating severely uncontrolled or refractory asthma (strength of recommendation [SOR], B); no comparable randomized trials of azithromycin have been conducted for new-onset asthma (SOR, C). Consider prescribing empiric azithromycin for patients with new-onset asthma in the context of shared decision making about potential benefits, harms, and consequences of chronic asthma (SOR, C).
It is important to note that wheezing is frequently associated with uncomplicated acute bronchitis that resolves spontaneously without antibiotic treatment.11 Azithromycin treatment for new-onset asthma should therefore be reserved for patients in whom apparent uncomplicated acute bronchitis fails to resolve after 3 to 6 months, and whose illness is diagnosable as asthma (see CASE 3).10
