What are safe antibiotic (abx) options for an 8-year-old with streptococcal pharyngitis (strep) or sinusitis?

Safe Antibiotic Options for an 8-Year-Old with Strep Pharyngitis or Sinusitis

For streptococcal pharyngitis, prescribe penicillin V (250 mg twice or three times daily) or amoxicillin (25 mg/kg twice daily, maximum 500 mg per dose) for 10 days; for acute bacterial sinusitis, prescribe amoxicillin (45 mg/kg/day in 2 divided doses) or high-dose amoxicillin-clavulanate (80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses) for 10-14 days. 1

Streptococcal Pharyngitis Treatment

First-Line Options

• Penicillin V remains the treatment of choice due to proven efficacy, safety, narrow spectrum, and low cost 1
• Dosing for children: 250 mg twice or three times daily for 10 days 1
• Amoxicillin is equally effective and often preferred in young children due to better palatability of the suspension 1
• Dosing: 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 1

Penicillin-Allergic Patients

• First-generation cephalosporins (e.g., cephalexin 20 mg/kg per dose twice daily, maximum 500 mg per dose) for 10 days 1
• Cefadroxil 30 mg/kg once daily (maximum 1 g) for 10 days 1
• Clindamycin 7 mg/kg per dose three times daily (maximum 300 mg per dose) for 10 days 1
• Azithromycin 12 mg/kg once daily (maximum 500 mg) for 5 days 1
• Clarithromycin 7.5 mg/kg per dose twice daily (maximum 250 mg per dose) for 10 days 1

Critical Caveat for Strep Throat

• Cephalosporins should not be used in patients with immediate hypersensitivity (anaphylaxis, urticaria) to β-lactam antibiotics 1
• Erythromycin resistance remains less than 5% in the United States, making macrolides acceptable alternatives 1

Acute Bacterial Sinusitis Treatment

Diagnosis Criteria (Must Meet One)

• Persistent illness: nasal discharge or daytime cough lasting >10 days without improvement 1
• Worsening course: new fever ≥38°C or increased nasal discharge/cough after initial improvement 1
• Severe onset: fever ≥39°C with purulent nasal discharge for ≥3 consecutive days 1

First-Line Antibiotic Selection

• Standard-dose amoxicillin 45 mg/kg/day in 2 divided doses for uncomplicated cases 1, 2, 3
• High-dose amoxicillin 80-90 mg/kg/day in 2 divided doses for areas with high prevalence of resistant S. pneumoniae 1, 2
• High-dose amoxicillin-clavulanate 80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses for children with risk factors 1, 2

Risk Factors Requiring High-Dose or Amoxicillin-Clavulanate

• Age <2 years 1, 2
• Daycare attendance 1, 2
• Recent antibiotic use within 4-6 weeks 1, 2
• Geographic areas with high prevalence of resistant S. pneumoniae (>10-15% nonsusceptible) 1, 3

Penicillin-Allergic Patients with Sinusitis

• Cefdinir, cefuroxime, or cefpodoxime are appropriate alternatives 1, 4, 3
• Cefpodoxime proxetil: 8 mg/kg/day in two doses 2
• Ceftriaxone 50 mg/kg (maximum 2 grams) as single intramuscular or intravenous dose for children unable to tolerate oral medication 1, 4

Treatment Duration

• 10-14 days for sinusitis, or until symptom-free for 7 days 1, 2, 3
• 10 days for strep pharyngitis 1

Critical Pitfalls to Avoid

Do NOT Use Azithromycin for Sinusitis

• Azithromycin should not be used for acute bacterial sinusitis due to 20-25% resistance rates among S. pneumoniae and H. influenzae 2, 5
• The FDA label indicates azithromycin is approved for sinusitis in adults but resistance patterns make it unsuitable 5
• French and American guidelines explicitly exclude macrolides from recommended therapy for sinusitis 2

Reassessment Timing

• Reassess at 72 hours if no improvement in children with sinusitis 1, 4
• Switch to second-line therapy (amoxicillin-clavulanate or cephalosporins) if worsening or no improvement 1, 2

When to Use Parenteral Therapy

• Child unable to tolerate oral medication (vomiting) 1, 4
• Failure of initial oral antibiotic therapy after 72 hours 4
• Ceftriaxone 50 mg/kg as single dose, then reassess at 24 hours 4

Microbiologic Coverage

The major pathogens in both conditions are 1, 3:

• Streptococcus pneumoniae (30% of sinusitis cases)
• Haemophilus influenzae (20% of sinusitis cases, 10-42% β-lactamase positive)
• Moraxella catarrhalis (20% of sinusitis cases, nearly 100% β-lactamase positive)
• Streptococcus pyogenes (strep pharyngitis)

Adjunctive Therapy for Sinusitis

• Intranasal corticosteroids may be beneficial as adjunct to antibiotics 2, 4
• Analgesics/antipyretics (acetaminophen, ibuprofen) for symptom control 1
• Avoid aspirin in children 1