What is the recommended treatment for a patient with mild to moderate bronchitis who is allergic to amoxicillin (amoxicillin)?

Medication Management for Bronchitis with Amoxicillin Allergy

Direct Answer

For patients with mild to moderate acute bronchitis who are allergic to amoxicillin, antibiotics should NOT be prescribed at all, as bronchitis is viral in 89-95% of cases and antibiotics provide no clinical benefit regardless of which agent is chosen. 1

Clinical Decision Algorithm

Step 1: Confirm the Diagnosis is Actually Bronchitis (Not Pneumonia)

Before considering any treatment, you must exclude pneumonia by evaluating: 1

• Heart rate >100 beats/min 1
• Respiratory rate >24 breaths/min 1
• Oral temperature >38°C 1
• Abnormal chest examination findings (rales, egophony, tactile fremitus) 1

If any of these are present, obtain chest radiography—this is pneumonia, not bronchitis, and requires different management. 1

Step 2: Provide Symptomatic Treatment Only

The cornerstone of acute bronchitis management is patient education and symptomatic treatment, not antibiotics. 1 Inform patients that: 1

• Cough typically lasts 10-14 days after the visit, even without antibiotics 1
• The condition is self-limiting and resolves within 3 weeks 1
• Patient satisfaction depends more on physician-patient communication than whether an antibiotic is prescribed 1

Symptomatic options include: 1

• Codeine or dextromethorphan for bothersome dry cough, especially when sleep is disturbed 1
• β2-agonist bronchodilators (albuterol) ONLY in select patients with accompanying wheezing 1
• Elimination of environmental cough triggers and vaporized air treatments 1

Step 3: The Exception—Pertussis (Whooping Cough)

If pertussis is confirmed or strongly suspected, prescribe a macrolide antibiotic immediately (erythromycin or azithromycin), as this is the ONE indication for antibiotics in acute bronchitis. 1 Patients must be isolated for 5 days from the start of treatment. 1

Step 4: When to Reassess

Instruct patients to return if: 1

• Fever persists >3 days (suggests bacterial superinfection or pneumonia) 1
• Cough persists >3 weeks (consider other diagnoses: asthma, COPD, pertussis, GERD) 1
• Symptoms worsen rather than gradually improve 1

Special Consideration: Chronic Bronchitis Exacerbations

If the patient has chronic bronchitis or COPD (not simple acute bronchitis), the approach differs entirely. 1 Consider antibiotics only if the patient has: 1

• Chronic respiratory insufficiency (dyspnea at rest and/or FEV1 <35% with hypoxemia PaO2 <60 mmHg) 1
• At least 2 of 3 Anthonisen criteria: increased sputum volume, increased sputum purulence, increased dyspnea 1
• Fever >38°C persisting for more than 3 days 1

Antibiotic Selection for Chronic Bronchitis Exacerbations (When Indicated)

For patients allergic to amoxicillin with chronic bronchitis exacerbations requiring antibiotics: 1, 2

First-line alternatives: 1

• Azithromycin 500 mg once daily for 3 days 3, 4, 5
• Clarithromycin extended-release 1000 mg once daily for 5-7 days 2
• Clarithromycin immediate-release 500 mg twice daily for 7-14 days 2
• Doxycycline 100 mg twice daily for 7-10 days 1

Second-line for severe exacerbations or FEV1 <35%: 1

• Respiratory fluoroquinolones (levofloxacin) 1
• Second or third-generation cephalosporins (if no cross-reactivity concern with penicillin allergy) 1

Critical Pitfalls to Avoid

Do NOT assume bacterial infection based on: 1

• Purulent sputum or sputum color—this occurs in 89-95% of VIRAL bronchitis cases 1
• Duration of cough alone—viral bronchitis cough normally lasts 10-14 days 1
• Patient expectation for antibiotics—explain the risks of unnecessary antibiotic use 1

Do NOT prescribe antibiotics before the 3-day fever threshold, as most cases are viral and will resolve spontaneously. 1

For children under 3 years with pneumonia (not bronchitis) and beta-lactam allergy, hospitalization is preferable for appropriate parenteral antibiotic therapy, as oral alternatives are not recommended. 6

Evidence Quality Note

The most recent and highest-quality evidence from multiple medical societies (American Academy of Family Physicians, American College of Chest Physicians, American Thoracic Society, Infectious Diseases Society of America) published in 2024-2026 is conclusive: antibiotics do not improve clinical outcomes in uncomplicated acute bronchitis, showing only a reduction of approximately half a day in cough duration while significantly increasing adverse events (RR 1.20; 95% CI 1.05-1.36). 1 The amoxicillin allergy is therefore irrelevant in most cases, as no antibiotic should be prescribed at all.