Amoxicillin Should Not Be Used for Acute Bronchitis
Amoxicillin is not effective for treating uncomplicated acute bronchitis and should not be prescribed, regardless of cough duration or sputum appearance. 1, 2
Why Antibiotics Don't Work
The overwhelming majority (89-95%) of acute bronchitis cases are caused by respiratory viruses, not bacteria. 2 The key bacterial pathogens that can cause acute bronchitis are limited to Bordetella pertussis, Mycoplasma pneumoniae, and Chlamydia pneumoniae—and amoxicillin is not the appropriate treatment for any of these organisms. 1
Multiple meta-analyses demonstrate that routine antibiotic treatment—including amoxicillin—reduces cough duration by only approximately half a day, a clinically insignificant benefit. 2, 3 This minimal benefit is far outweighed by the risks of adverse effects and contribution to antibiotic resistance. 2, 3
Common Pitfalls to Avoid
The Purulent Sputum Trap
Many clinicians mistakenly believe that green or yellow (purulent) sputum indicates bacterial infection requiring antibiotics. This is incorrect. Purulence occurs when inflammatory cells or sloughed mucosal epithelial cells are present, which happens with both viral and bacterial infections. 1, 2 Sputum color should never be used as justification for prescribing antibiotics in acute bronchitis. 2
Rule Out Pneumonia First
Before diagnosing acute bronchitis, you must exclude pneumonia by checking for: 1, 2
- Tachycardia (>100 beats/min)
- Tachypnea (>24 breaths/min)
- Fever (>38°C)
- Asymmetrical lung sounds or other abnormal chest examination findings
In healthy, non-elderly adults without these findings, chest radiography is usually not indicated. 1
The One Exception: Pertussis
If pertussis is suspected (not amoxicillin, but a macrolide like erythromycin should be prescribed). 1, 2 However, this is an unusual circumstance, typically occurring during known outbreaks with high probability of exposure. 1 Antibiotics for pertussis primarily decrease pathogen shedding rather than resolve symptoms, especially if started more than 7-10 days after illness onset. 1, 2
What to Do Instead
Symptomatic Management
Offer symptomatic relief with: 2
- Cough suppressants (dextromethorphan or codeine)
- Expectorants (guaifenesin)
- First-generation antihistamines (diphenhydramine)
- Decongestants (phenylephrine)
Do not routinely prescribe β-agonist bronchodilators unless the patient has underlying asthma or COPD. 2
Critical Patient Communication
Patient satisfaction depends on communication quality, not antibiotic prescription. 1, 2 You should: 1, 2
- Set realistic expectations: Explain that cough typically lasts 10-14 days after the visit
- Reframe the diagnosis: Call it a "chest cold" rather than "bronchitis" to reduce antibiotic expectations
- Explain antibiotic risks: Discuss side effects (nausea, vomiting, diarrhea) and contribution to antibiotic resistance
- Personalize the risk: Previous antibiotic use increases likelihood of carrying and being infected with antibiotic-resistant bacteria 1
Important Caveats
These recommendations apply only to uncomplicated acute bronchitis in otherwise healthy adults. 1, 2 They do not apply to: 2
- Elderly patients
- Patients with COPD exacerbations
- Patients with congestive heart failure
- Immunosuppressed patients
For cough lasting longer than 3 weeks, consider chest radiography to evaluate for other causes, as this exceeds the definition of acute bronchitis. 1