When to Start Antibiotics in Acute Wheezy Bronchitis (LRTI)
In an otherwise healthy adult with acute wheezy bronchitis, antibiotics should generally NOT be started, as this condition is predominantly viral and self-limiting. 1, 2
Evidence Against Routine Antibiotic Use
The most compelling evidence comes from multiple high-quality sources demonstrating minimal benefit:
Acute bronchitis in healthy adults is rarely bacterial. The French guidelines explicitly state that bacteria (Mycoplasma pneumoniae, Chlamydia pneumoniae, Bordetella pertussis) are involved "on very rare occasion" in healthy adults with acute bronchitis 1
Antibiotics provide negligible clinical benefit. A large prospective study of 367 adults with lower respiratory tract infections found that over 50% had evidence of infection (bacterial or atypical), yet the outcome was unrelated to identified pathogens or antibiotic use—many patients improved without antibiotics 2
The benefit-to-harm ratio does not favor treatment. A meta-analysis of randomized controlled trials showed antibiotics decreased cough duration by only 0.5 days (not statistically significant) while causing side effects 3. The 2013 GRACE trial of 2,061 patients confirmed amoxicillin provided no significant benefit for symptom duration or severity in acute LRTI when pneumonia was not suspected 4
Official guidelines recommend against antibiotics. The French guidelines state: "As a rule, antibiotics should not be prescribed in the treatment of acute bronchitis in healthy adults" with Grade B evidence 1
When Antibiotics ARE Indicated
You should consider antibiotics only in these specific situations: 1
High-Risk Patient Factors
- Age >75 years with fever 1
- Cardiac failure 1
- Insulin-dependent diabetes mellitus 1
- Serious neurological disorder (stroke, etc.) 1
Clinical Features Suggesting Pneumonia (Not Simple Bronchitis)
- Fever >37.8°C persisting >4 days 1
- New focal chest signs on auscultation (crepitations, rales) 1
- Tachypnea >25 breaths/min 1
- Tachycardia >100 bpm 1
- Dyspnea or chest pain 1
If pneumonia is suspected based on these features, obtain a chest radiograph to confirm the diagnosis before starting antibiotics. 1
COPD Exacerbations (Not Simple Bronchitis)
Antibiotics are indicated only when all three cardinal symptoms are present: 1
- Increased dyspnea
- Increased sputum volume
- Increased sputum purulence
Recommended Antibiotic Regimen (When Indicated)
If you determine antibiotics are necessary based on the above criteria:
- First-line: Amoxicillin 500-1000 mg every 8 hours for 5-7 days 5
- Penicillin allergy: Doxycycline 100 mg twice daily OR macrolides (clarithromycin 250-500 mg twice daily) 5
- Treatment failures or high resistance: Consider fluoroquinolones (levofloxacin, moxifloxacin) 1
Critical Pitfalls to Avoid
Do not prescribe antibiotics based solely on purulent sputum. The onset of purulent sputum during acute bronchitis in healthy adults is NOT associated with bacterial superinfection 1
Do not assume fever alone warrants antibiotics. Fever persisting >7 days would be indicative of bacterial superinfection, but shorter durations are consistent with viral illness 1
Avoid NSAIDs or systemic corticosteroids. These are not justified in acute bronchitis 1
Recognize that wheezing suggests airway inflammation, not bacterial infection. Consider chronic airway disease if the patient has wheezing, prolonged expiration, smoking history, and allergy symptoms 1
Patient Counseling
Advise patients to return if: 1, 5
- Symptoms persist >3 weeks
- Fever persists >48 hours after initial assessment
- Clinical deterioration occurs at any time
Reassure patients that: 2
- Cough may persist for several weeks even without bacterial infection
- Most cases are viral and self-limiting
- Antibiotics will not significantly shorten symptom duration in uncomplicated cases