Treatment for Acute Infection
The recommended treatment for acute infection depends on the type of infection, with amoxicillin being the first-line antibiotic for many respiratory infections, particularly pneumococcal pneumonia, while amoxicillin-clavulanate is preferred for more complex infections or when antibiotic resistance is a concern. 1
Approach to Antibiotic Selection
- Differentiate between upper respiratory tract infections (URTI) and lower respiratory tract infections (LRTI) based on clinical presentation 1
- Consider the likely pathogens based on the specific infection type and patient age 1
- Evaluate risk factors for resistant organisms, including recent antibiotic use (within 4-6 weeks) 1
- Assess severity of illness to determine appropriate antibiotic choice and route of administration 1
Respiratory Tract Infections
Upper Respiratory Tract Infections
- Most acute rhinosinusitis cases are viral and self-limited, requiring only supportive care 1
- Bacterial rhinosinusitis should be suspected when symptoms persist >10 days without improvement, symptoms are severe (fever >39°C, purulent nasal discharge, facial pain for >3 consecutive days), or symptoms worsen after initial improvement 1
- For acute bacterial rhinosinusitis in adults:
Lower Respiratory Tract Infections
Acute Bronchiolitis
- Primarily viral; antibiotics generally not indicated as first-line therapy 1
- Consider antibiotics only in specific situations:
- High fever (>38.5°C) persisting >3 days
- Associated purulent acute otitis media
- Confirmed pneumonia/atelectasis on chest X-ray 1
- When indicated, use amoxicillin-clavulanate, cefuroxime-axetil, or cefpodoxime-proxetil 1
Community-Acquired Pneumonia
- For adults without risk factors:
- First-line: Amoxicillin 3g/day 1
- For adults with risk factors (recent antibiotics, immunodeficiency):
- Amoxicillin-clavulanate, parenteral 2nd/3rd generation cephalosporin, or respiratory fluoroquinolone 1
- For children <3 years:
- First-line: Amoxicillin 80-100 mg/kg/day in three daily doses 1
- For children >3 years:
- For suspected pneumococcal infection: Amoxicillin as above
- For suspected atypical bacteria (Mycoplasma, Chlamydia): Macrolides 1
Intra-abdominal Infections
- For mild-to-moderate community-acquired infections:
- Ticarcillin-clavulanate, cefoxitin, ertapenem, moxifloxacin, or tigecycline as single agents
- Alternatively, combinations of metronidazole with cefazolin, cefuroxime, ceftriaxone, cefotaxime, levofloxacin, or ciprofloxacin 1
- Avoid ampicillin-sulbactam due to high resistance rates among community-acquired E. coli 1
- Avoid cefotetan and clindamycin due to increasing resistance among Bacteroides fragilis 1
Dosing Considerations
- Amoxicillin-clavulanate can be administered twice daily (875mg/125mg) instead of three times daily (500mg/125mg) with equivalent efficacy 3, 4
- For children, amoxicillin or amoxicillin-clavulanate can be given once or twice daily instead of three times daily with comparable effectiveness 5
- Treatment duration:
Special Considerations
- Assess response to therapy after 2-3 days; if no improvement or worsening, consider alternative antibiotics 1
- For beta-lactam allergies, options include:
- Recent studies suggest ceftriaxone may be more effective than amoxicillin-clavulanate for short-course therapy of acute bacterial rhinosinusitis 6
- For influenza, oseltamivir is indicated for treatment when symptoms have been present for ≤48 hours 7
Common Pitfalls to Avoid
- Prescribing antibiotics for viral infections (most URIs, acute bronchitis) 1
- Using broad-spectrum antibiotics when narrow-spectrum would suffice 1
- Failing to adjust therapy based on local resistance patterns 1
- Not considering recent antibiotic use when selecting empiric therapy 1
- Inadequate duration of therapy leading to treatment failure or recurrence 1