What is the appropriate use of antibiotics, such as penicillin (Penicillin) or amoxicillin (Amoxicillin), for upper respiratory tract infections (URTI) in patients with suspected bacterial infections, considering factors like local resistance patterns and patient medical history?

Antibiotics for Upper Respiratory Tract Infections

Do Not Prescribe Antibiotics for Most URTIs

Most upper respiratory tract infections are viral and antibiotics should not be prescribed—they cause more harm than benefit and do not hasten recovery or prevent complications. 1, 2, 3

The vast majority of URTIs (common cold, acute bronchitis, viral pharyngitis, laryngitis) resolve spontaneously within 10 days regardless of antibiotic use. 4, 1 Antibiotics do not prevent bacterial superinfection in healthy patients, and purulent sputum during acute bronchitis does not indicate bacterial infection requiring treatment. 4

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When Antibiotics ARE Indicated

Antibiotics should be reserved for these specific bacterial infections only:

Acute Bacterial Rhinosinusitis (ABRS)

Prescribe antibiotics ONLY when patients meet one of these three criteria: 1, 2

• Persistent symptoms ≥10 days without improvement (most common indication)
• Severe symptoms: fever >39°C with purulent nasal discharge or facial pain for ≥3 consecutive days
• "Double sickening": worsening after initial improvement following typical viral URI

First-line treatment: Amoxicillin-clavulanate 4, 1, 2

• Adults: 875 mg/125 mg every 12 hours for 7-10 days 2
• Children: 80-100 mg/kg/day (of amoxicillin component) in 3 divided doses 2

Alternative options (if amoxicillin-clavulanate contraindicated): 1

• Doxycycline
• Respiratory fluoroquinolones (levofloxacin, moxifloxacin)
• Second-generation cephalosporins (cefuroxime-axetil)
• Third-generation cephalosporins (cefpodoxime-proxetil, cefotiam-hexetil)

Critical pitfall: Cefixime, ciprofloxacin, ofloxacin, and first-generation cephalosporins (like cephalexin) are NOT appropriate due to inadequate pneumococcal coverage. 1

Streptococcal Pharyngitis

First-line: Amoxicillin for 10 days to prevent acute rheumatic fever 1, 5

• Penicillin V is also acceptable 6
• Must have confirmed diagnosis (rapid strep test or culture)

Acute Otitis Media (AOM)

Immediate antibiotics indicated for: 1, 5

• All children <2 years with confirmed AOM
• Children ≥2 years with severe symptoms (high fever, intense earache, bilateral AOM, or purulent conjunctivitis)

Watchful waiting appropriate for: 5

• Children >2 years with uncomplicated AOM without severe features
• Reassess at 48-72 hours; prescribe antibiotics if no improvement

First-line: High-dose amoxicillin (80-90 mg/kg/day for children) 5

Frontal, Ethmoidal, or Sphenoidal Sinusitis

These require immediate antibiotic therapy due to risk of serious complications. 4

• Consider fluoroquinolones (levofloxacin, moxifloxacin) for frontal/sphenoidal involvement 4

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What NOT to Prescribe

Never use these antibiotics for respiratory infections: 1

• First-generation cephalosporins (cephalexin) - inadequate pneumococcal coverage
• Cefixime - inadequate pneumococcal coverage
• Ciprofloxacin or ofloxacin - inadequate pneumococcal coverage
• Trimethoprim-sulfamethoxazole - resistance concerns

Plain amoxicillin alone is inferior to amoxicillin-clavulanate for sinusitis due to beta-lactamase-producing H. influenzae and M. catarrhalis. 4, 2

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Monitoring and Treatment Failure

Assess response within 48-72 hours: 4, 1

• Fever should resolve within 24 hours (pneumococcal) to 2-4 days (other bacteria) 1
• Cough may persist longer and does not indicate treatment failure 1

If no improvement after 72 hours: 1, 5

• Switch amoxicillin to amoxicillin-clavulanate
• Re-examine to confirm diagnosis
• Consider imaging or specialist referral for recurrent failures

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Supportive Care (Always Appropriate)

Regardless of antibiotic decision, provide: 1, 2

• Analgesics (acetaminophen, ibuprofen) for pain/fever
• Intranasal saline irrigation
• Intranasal corticosteroids for symptom relief
• Decongestants as needed

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Key Considerations for Local Resistance

While the question mentions considering local resistance patterns, the guidelines prioritize amoxicillin-clavulanate specifically because it covers beta-lactamase-producing organisms and penicillin-resistant S. pneumoniae. 4, 2 In areas with high amoxicillin resistance in H. influenzae, amoxicillin-clavulanate is preferred over amoxicillin alone. 2

Common pitfall: Prescribing antibiotics "just in case" or for patient satisfaction contributes to resistance and causes unnecessary adverse events (particularly GI side effects with amoxicillin-clavulanate). 2, 3