Antibiotics for Bronchial Asthma

Antibiotics should NOT be routinely prescribed for patients with bronchial asthma unless there is clear evidence of bacterial infection. 1

Assessment for Bacterial Infection

Antibiotics should only be considered if fever (>38°C) persists for more than 3 days, suggesting bacterial infection 1
Purulent sputum or change in sputum color (green or yellow) alone does not necessarily indicate bacterial infection and is not sufficient justification for antibiotic therapy 1
Consider antibiotics only when at least two of the three Anthonisen criteria are present: increased sputum volume, increased sputum purulence, and increased dyspnea 1, 2
Obtain sputum culture and sensitivity to identify potential pathogens, especially looking for Pseudomonas aeruginosa in patients with severe or recurrent infections 2

Amoxicillin is recommended as the first-line treatment for bronchial asthma with suspected bacterial infection 1
First-generation cephalosporins are an alternative option for first-line treatment 1
For patients with penicillin allergy, macrolides (such as azithromycin), pristinamycin, or doxycycline can be considered 1

Amoxicillin-clavulanate is the reference second-line therapy when first-line antibiotics fail 1, 2
Second-generation (cefuroxime-axetil) or third-generation (cefpodoxime-proxetil) oral cephalosporins are also second-line options 1
Respiratory fluoroquinolones (levofloxacin, moxifloxacin) can be used as second-line treatment, particularly for patients with frequent exacerbations 1, 2

Inhaled colistin is recommended as the first-line inhaled antibiotic for patients with bronchiectasis and chronic P. aeruginosa infection 2, 3
Inhaled gentamicin is considered a second-line alternative to colistin for P. aeruginosa infection 2, 3
Consider azithromycin or erythromycin as an alternative if a patient does not tolerate inhaled antibiotics 3

Antibiotic therapy should be active against common respiratory pathogens:
- Streptococcus pneumoniae 1
- Haemophilus influenzae 1, 4
- Moraxella catarrhalis (formerly Branhamella catarrhalis) 1, 4
- Atypical organisms such as Mycoplasma pneumoniae and Chlamydia pneumoniae may be considered in specific cases 5, 6

Traditional courses of antibiotics (7-10 days) are appropriate for acute bacterial infections 4
For chronic infections, particularly with atypical organisms, longer courses (≥6 weeks) of doxycycline or macrolides may be needed 5

Most acute exacerbations of asthma are triggered by viral respiratory pathogens, not bacteria 7, 5
Administration of antibiotics for acute exacerbations of asthma without evidence of bacterial infection has been shown to be ineffective 5
Recent research suggests that antibiotic treatment in acute exacerbation of asthma might actually lead to longer asthmatic symptoms, particularly in patients with pharyngeal S. pneumoniae colonization 8
Macrolides may have additional non-antimicrobial anti-inflammatory effects that could be beneficial in asthma management 6

Prescribing antibiotics for acute asthma exacerbations in healthy adults without clear indications of bacterial infection 1
Assuming purulent sputum indicates bacterial infection 1
Failing to distinguish between viral and bacterial triggers of asthma exacerbations 7
Using antibiotics with inadequate coverage against common respiratory pathogens 1
Using fluoroquinolones inactive against pneumococci (ofloxacin, ciprofloxacin) or cefixime 1

Review patients on long-term antibiotics every 6 months to assess efficacy, toxicity, and continuing need 2
Monitor for adverse effects, particularly with fluoroquinolones (tendon issues) and aminoglycosides (renal and ototoxicity) 2
Regularly obtain sputum cultures in patients with recurrent infections to guide antibiotic selection 2