What is the antibiotic of choice for acute bronchitis?

Antibiotics Are Not Recommended for Acute Bronchitis

Antibiotics should not be prescribed for the treatment of acute bronchitis in otherwise healthy adults, as the condition is primarily viral in etiology and antibiotics provide minimal clinical benefit while increasing the risk of adverse effects. 1, 2

Etiology and Pathophysiology

• Acute bronchitis is predominantly caused by respiratory viruses (89-95% of cases), including influenza, rhinovirus, coronavirus, and adenovirus 2
• Non-viral pathogens are rarely involved (<10% of cases) and include Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Bordetella pertussis 1, 2
• The clinical course is generally self-limiting with spontaneous improvement after about 10 days, although cough may persist longer 1
• Purulent sputum or change in sputum color (green/yellow) does not indicate bacterial infection but is due to inflammatory cells or sloughed mucosal epithelial cells 1, 2

Evidence Against Antibiotic Use

• Multiple guidelines and systematic reviews demonstrate that antibiotics provide minimal benefit in acute bronchitis 1, 2
• The benefit of antibiotic therapy on clinical course or prevention of complications has not been confirmed in clinical trials versus placebo (Grade B evidence) 1
• Meta-analyses show antibiotics reduce cough duration by only about half a day, which is not clinically significant 2, 3
• Antibiotics are associated with increased adverse events compared to placebo (16% vs. 11%) 2
• As a rule, antibiotics should not be prescribed in the treatment of acute bronchitis in healthy adults 1

Distinguishing Acute Bronchitis from Pneumonia

• Pneumonia should be ruled out in patients with:
  • Tachycardia (heart rate >100 beats/min)
  • Tachypnea (respiratory rate >24 breaths/min)
  • Fever (oral temperature >38°C)
  • Abnormal findings on chest examination (rales, egophony, or tactile fremitus) 1, 2
• Fever persisting more than 7 days may indicate bacterial superinfection 1

Exception for Pertussis

• For confirmed or suspected pertussis (whooping cough), a macrolide antibiotic such as azithromycin should be prescribed 2
• Early treatment (within the first few weeks) helps prevent disease spread rather than to resolve symptoms 2

Recommended Symptomatic Management

• Consider symptomatic relief with:
  • Cough suppressants (dextromethorphan or codeine)
  • Expectorants (guaifenesin)
  • First-generation antihistamines (diphenhydramine)
  • Decongestants (phenylephrine) 1, 2
• β-agonist bronchodilators are not recommended for routine use in patients without asthma or COPD 1, 2
• Over-the-counter symptomatic treatments may cause minor adverse effects including nausea, vomiting, headache, and drowsiness 1, 2
• For influenza-related bronchitis, antiviral medications may be considered if within 48 hours of symptom onset 2

Patient Communication Strategies

• Inform patients that cough typically lasts 10-14 days after the office visit 2
• Refer to the condition as a "chest cold" rather than bronchitis to reduce antibiotic expectations 2
• Explain that patient satisfaction depends more on physician-patient communication than whether an antibiotic is prescribed 2
• Discuss the risks of unnecessary antibiotic use, including side effects and contribution to antibiotic resistance 2

Special Considerations

• These recommendations do not apply to elderly patients or those with comorbid conditions such as COPD, congestive heart failure, or immunosuppression 2
• The prescription of NSAIDs at an anti-inflammatory dose level or systemic corticosteroids is not justified for acute bronchitis 1