Recommended Outpatient Antibiotics for Common Bacterial Infections
For common bacterial infections in the outpatient setting, short-course antibiotic therapy with specific agents based on the infection type is recommended to reduce antibiotic resistance while maintaining clinical efficacy. 1
Urinary Tract Infections (UTIs)
Uncomplicated Cystitis in Women
First-line options (preferred due to lower collateral damage):
- Nitrofurantoin 100mg twice daily for 5 days
- Trimethoprim-sulfamethoxazole (TMP-SMX) 160/800mg twice daily for 3 days
- Fosfomycin 3g as a single dose 1
Second-line options (when first-line agents cannot be used):
- Oral cephalosporins (cephalexin, cefixime)
- Amoxicillin-clavulanate
- Fluoroquinolones (only when other options unsuitable due to resistance concerns) 2
Uncomplicated Pyelonephritis
Oral treatment options:
- Fluoroquinolones for 5-7 days (if local resistance <10%)
- TMP-SMX for 14 days (only when susceptibility is confirmed) 1
Important caveat: Do not use TMP-SMX empirically for pyelonephritis without culture and susceptibility testing due to increasing resistance rates 1
MRSA UTIs
- For confirmed MRSA UTIs:
- TMP-SMX 4 mg/kg/dose (based on TMP) every 8-12 hours
- Nitrofurantoin 100 mg every 6 hours (for lower UTI only) 3
Community-Acquired Pneumonia (CAP)
- Treatment duration: Minimum of 5 days
- Extension criteria: Continue beyond 5 days only if patient has not achieved clinical stability (defined as resolution of vital sign abnormalities, ability to eat, and normal mentation) 1
- Evidence: Recent studies show 5-day courses are as effective as longer courses with fewer adverse events 1
COPD Exacerbations with Bacterial Infection
- Treatment duration: Limit to 5 days
- Indication for antibiotics: Clinical signs of bacterial infection (increased sputum purulence plus increased dyspnea and/or increased sputum volume) 1
Nonpurulent Cellulitis
- Treatment duration: 5-6 day course
- Antibiotic choice: Agents active against streptococci
- Patient criteria: Particularly appropriate for patients able to self-monitor and with close primary care follow-up 1
Key Considerations for Antibiotic Selection
Patient risk factors and antibiotic history:
- Recent exposure to specific antibiotics increases risk of resistance
- Consider individual comorbidities and allergies 1
Local resistance patterns:
Collateral damage concerns:
Medication administration:
- Amoxicillin-clavulanate should be taken with meals to reduce GI upset
- Complete the full prescribed course even if symptoms improve quickly 5
Common Pitfalls to Avoid
- Overtreatment of asymptomatic bacteriuria: Only treat in pregnancy or before urologic procedures 1
- Default 10-day courses: Evidence supports shorter courses for many infections 1
- Empiric fluoroquinolone use for uncomplicated cystitis: Reserve for more serious infections due to resistance concerns and adverse effects 1, 2
- Failure to adjust for local resistance patterns: Consider local antibiogram data when available 2
- Incomplete courses: Emphasize to patients the importance of completing the prescribed course to prevent resistance development 5
Special Populations
- Diabetic women with uncomplicated cystitis: Treat similarly to non-diabetic women if no voiding abnormalities are present 6
- Men with UTIs: Limited evidence supports 7-14 days of therapy 6
- Pregnant women: Avoid TMP-SMX in the third trimester 3
- Children under 8: Avoid tetracyclines 3
By following these evidence-based recommendations for outpatient antibiotic therapy, clinicians can effectively treat common bacterial infections while minimizing the risk of antibiotic resistance and adverse effects.