When should antibiotics be prescribed for cough or common cold, and what are the recommended first‑line agents for bacterial pneumonia, acute bacterial sinusitis, streptococcal pharyngitis, or pertussis?

When to Prescribe Antibiotics for Cough and Colds

Antibiotics should NOT be prescribed for the common cold, acute bronchitis, or uncomplicated acute cough, as these conditions are viral and antibiotics provide no clinical benefit while causing significant adverse effects. 1

Conditions Where Antibiotics Are NOT Indicated

Common Cold (Viral Upper Respiratory Infection)

• Do not prescribe antibiotics for common cold symptoms including rhinorrhea, nasal congestion, sneezing, sore throat, cough, low-grade fever, headache, and malaise. 1, 2
• Antibiotics do not reduce symptom duration, prevent complications (bacterial sinusitis, otitis media, asthma exacerbation), or decrease work time lost. 1, 3
• The presence of purulent (green/yellow) nasal discharge does NOT indicate bacterial infection and should not trigger antibiotic therapy. 2, 3
• Number needed to harm from antibiotics is 8, while number needed to treat for rapid cure is 18. 1

Acute Bronchitis

• Routine antibiotic treatment of uncomplicated acute bronchitis is not recommended, regardless of cough duration. 1
• Antibiotics are not indicated for acute bronchitis, asthma, or mild exacerbations of chronic bronchitis related to smoking or environmental irritants. 1
• Most acute bronchitis is viral and self-limited, improving within 10-14 days. 1

Acute Cough (< 4 Weeks Duration)

• Cough will be worst during the first few days of a viral infection and should gradually improve over 1-2 weeks. 1
• Treat with first-generation antihistamine/decongestant (brompheniramine with sustained-release pseudoephedrine) or naproxen for symptomatic relief. 1
• Newer nonsedating antihistamines are ineffective and should not be used. 1

When Antibiotics ARE Indicated

Bacterial Pneumonia

• Antibiotics are appropriate when clinical findings suggest pneumonia (fever, tachypnea, rales, hypoxia, chest radiograph infiltrate). 1
• Amoxicillin is the first-line agent for community-acquired pneumonia. 3
• Macrolides (azithromycin) may be used for atypical pathogens (Mycoplasma, Chlamydia). 3

Acute Bacterial Sinusitis

• Reserve antibiotics for patients meeting ANY of these criteria: 1
  • Persistent symptoms for >10 days without improvement (most common presentation)
  • Severe symptoms: fever ≥39°C (102.2°F) AND purulent nasal discharge or facial pain for ≥3 consecutive days
  • "Double sickening": worsening symptoms after initial improvement (typically after 5-7 days)
• Do NOT diagnose bacterial sinusitis during the first week of symptoms, as viral rhinosinusitis causes sinus abnormalities in 87% of patients. 1
• Amoxicillin or amoxicillin-clavulanate are first-line agents. 1

Group A Streptococcal Pharyngitis

• Antibiotics are appropriate ONLY after laboratory confirmation (rapid antigen test or throat culture). 3
• Testing should be limited to patients with fever, anterior cervical adenitis, and tonsillar exudates. 3
• Penicillin or amoxicillin are first-line agents. 1

Pertussis (Whooping Cough)

• Antibiotics are effective if given early in the illness for Bordetella pertussis infection. 1
• Macrolides (azithromycin, clarithromycin) are first-line agents. 1

Severe Chronic Bronchitis

• Antibiotics may be beneficial for exacerbations of bronchiectasis and severe chronic bronchitis in current or previous smokers with severe airflow obstruction. 1

Clinical Algorithm for Decision-Making

If cough worsens (biphasic course) or does not steadily improve after the first week, consider bacterial complications such as sinusitis or pertussis. 1

Week 1 of Symptoms:

• Assume viral etiology
• Provide symptomatic treatment only
• Do NOT prescribe antibiotics 1, 2

Days 7-10:

• If symptoms are improving: continue supportive care
• If symptoms persist unchanged: continue observation, no antibiotics yet 1

Day 10+:

• Persistent symptoms without improvement → consider bacterial sinusitis, prescribe antibiotics 1

Any Time Point:

• Severe symptoms (fever ≥39°C + purulent discharge + facial pain ≥3 days) → prescribe antibiotics for bacterial sinusitis 1
• Worsening after initial improvement → prescribe antibiotics for bacterial sinusitis 1
• Clinical pneumonia suspected → prescribe antibiotics 1

Harms of Inappropriate Antibiotic Use

• Adult patients treated with antibiotics for common cold have 3.6 times increased risk of adverse effects (diarrhea, rash, nausea). 1
• Previous antibiotic use increases likelihood of carriage and infection with antibiotic-resistant bacteria. 1, 3
• Rare but serious reactions include anaphylaxis, Stevens-Johnson syndrome, and sudden cardiac death. 3
• Contributes to Clostridioides difficile infection (29,300 deaths annually in the U.S.). 3

Common Pitfalls to Avoid

• Do not prescribe antibiotics based solely on purulent nasal discharge – this occurs in the vast majority of viral URIs. 2, 3
• Do not diagnose bacterial sinusitis in the first 7 days of symptoms – viral infections cause identical sinus imaging abnormalities. 1
• Do not assume antibiotics will accelerate recovery – they provide no benefit for viral infections. 1, 3
• Do not use cough duration alone as an indication for antibiotics – viral coughs can persist 10-14 days normally. 1