What antibiotics are used to treat common bacterial infections?

Antibiotics for Common Bacterial Infections

The most appropriate antibiotics for common bacterial infections are determined by the WHO's AWaRe framework, which categorizes antibiotics as Access, Watch, or Reserve based on their importance, resistance potential, and clinical use. 1

First-Line Antibiotics (Access Group)

• Amoxicillin is the first-line treatment for community-acquired pneumonia in children, particularly for pneumococcal pneumonia at a dose of 80-100 mg/kg/day in three daily doses for children weighing less than 30 kg 1
• Amoxicillin-clavulanate is recommended for:
  • Acute maxillary sinusitis (7-10 days) 1
  • Acute bronchiolitis with persistent high fever (>38.5°C for >3 days) 1
  • Community-acquired respiratory infections with beta-lactamase-producing pathogens 2
• For uncomplicated urinary tract infections in women, short-course therapy is recommended with:
  • Nitrofurantoin for 5 days
  • Trimethoprim-sulfamethoxazole (TMP-SMX) for 3 days
  • Fosfomycin as a single dose 1

Second-Line Antibiotics (Watch Group)

• Cephalosporins (cefuroxime-axetil, cefpodoxime-proxetil) are recommended as alternatives for:
  • Acute sinusitis (5-7 days) 1
  • Respiratory infections with beta-lactamase-producing pathogens 1
• Fluoroquinolones (levofloxacin, moxifloxacin) should be reserved for:
  • Complicated frontal, fronto-ethmoidal, or sphenoidal sinusitis 1
  • Uncomplicated pyelonephritis (5-7 days) when susceptibility is known 1
  • Failure of first-line therapy in maxillary sinusitis 1
• Macrolides are recommended for:
  • Children over 3 years with pneumonia suggestive of atypical pathogens (Mycoplasma pneumoniae, Chlamydia pneumoniae) 1
  • Patients with penicillin allergy 1

Special Populations

Pediatric Patients

• For neonatal sepsis with thrombocytopenia, ampicillin plus gentamicin is the safest and most effective first-line regimen 3
• In children under 3 years with bronchitis and fever persisting more than 3 days, beta-lactams (amoxicillin, amoxicillin-clavulanate, cefuroxime-axetil or cefpodoxime-proxetil) are recommended 1
• For children over 3 years with bronchitis, macrolides are the preferred option 1

Skin and Soft Tissue Infections

• For impetigo: oral dicloxacillin, cefalexin, erythromycin, clindamycin, or amoxicillin-clavulanate 1
• For purulent skin infections (likely Staphylococcus aureus): dicloxacillin, cefazolin, clindamycin, cefalexin, doxycycline, or trimethoprim-sulfamethoxazole 1
• For MRSA infections: vancomycin, linezolid, clindamycin, daptomycin, ceftaroline, doxycycline, or trimethoprim-sulfamethoxazole 1

Antibiotic Resistance Considerations

• The WHO AWaRe classification helps guide appropriate antibiotic use to minimize resistance development 1
• Access antibiotics have lower resistance potential and should be widely available and affordable 1
• Watch antibiotics have higher resistance potential and should be monitored through stewardship programs 1
• Reserve antibiotics should only be used when other alternatives are inadequate 1

Common Pitfalls to Avoid

• Using antibiotics for viral infections such as the common cold 4
• Discontinuing antibiotics prematurely, which may decrease treatment effectiveness and increase resistance development 4
• Not completing the full course of therapy as prescribed 4
• Using fluoroquinolones empirically for uncomplicated infections due to their high propensity for adverse effects 1
• Failing to adjust therapy based on culture results when available 1
• Not considering local resistance patterns when selecting empiric therapy 1

Administration Guidelines

• Amoxicillin-clavulanate should be taken with meals or snacks to reduce gastrointestinal upset 4
• Patients should be advised that diarrhea is a common side effect of antibiotics and to contact their physician if it is severe or lasts more than 2-3 days 4
• For pediatric liquid formulations, proper dosing devices (spoon or dropper) should be used and rinsed after each use 4

Remember that antibiotic selection should target the most likely pathogens for each infection type while considering local resistance patterns to optimize treatment outcomes and minimize resistance development.