What are the recommendations for outpatient treatment of a bacterial infection?

Outpatient Treatment Recommendations for Bacterial Infections

For outpatient treatment of bacterial infections, empirical antibiotic therapy should be selected based on the suspected pathogen, infection site, and patient factors, with narrow-spectrum agents preferred when appropriate to reduce adverse effects and antimicrobial resistance.

Skin and Soft Tissue Infections (SSTIs)

Cutaneous Abscesses

• Incision and drainage is the primary treatment for simple abscesses or boils 1
• Antibiotic therapy is recommended for abscesses with: severe/extensive disease, rapid progression with cellulitis, systemic illness, comorbidities/immunosuppression, extremes of age, difficult-to-drain locations, septic phlebitis, or lack of response to drainage alone 1

Cellulitis

• For purulent cellulitis (with drainage/exudate without drainable abscess):

  • Empirical therapy for CA-MRSA is recommended pending culture results 1
  • 5-10 days of therapy is recommended, individualized based on clinical response 1

• For non-purulent cellulitis (no drainage/exudate/abscess):

  • Empirical therapy for β-hemolytic streptococci is recommended 1
  • Consider empirical CA-MRSA coverage in patients who don't respond to β-lactam therapy or have systemic toxicity 1
  • 5-10 days of therapy is recommended, individualized based on clinical response 1

Recommended Oral Antibiotics for SSTI

• For CA-MRSA coverage: clindamycin, trimethoprim-sulfamethoxazole (TMP-SMX), doxycycline/minocycline, or linezolid 1
• For combined β-hemolytic streptococci and CA-MRSA coverage: clindamycin alone, TMP-SMX or tetracycline plus β-lactam (e.g., amoxicillin), or linezolid alone 1
• Rifampin is not recommended as monotherapy or adjunctive therapy 1

Cultures

• Obtain cultures from abscesses and purulent SSTIs when: antibiotic therapy is used, severe local infection or systemic illness is present, inadequate response to initial treatment occurs, or cluster/outbreak concerns exist 1

Community-Acquired Pneumonia (CAP)

Otherwise Healthy Adults

• Narrow-spectrum antibiotics are preferred for otherwise healthy outpatients with CAP 2:
  • Macrolide (e.g., azithromycin) or doxycycline 1
  • Consider local pneumococcal resistance patterns - macrolides should not be used as monotherapy when pneumococcal resistance exceeds 25% 1

Adults with Comorbidities

• Broad-spectrum antibiotics are recommended for outpatients with comorbidities (diabetes, chronic heart/liver/renal disease) 2:
  • Respiratory fluoroquinolone (e.g., levofloxacin, moxifloxacin) 1
  • β-lactam plus macrolide combination 1
  • β-lactam plus doxycycline combination 2

Treatment Duration

• 5-7 days of therapy is typically sufficient for CAP 3
• Shorter courses are associated with fewer adverse drug events compared to longer courses 3

Acute Bacterial Sinusitis

First-line Treatment

• For patients without recent antibiotic use (past 4-6 weeks):
  • Amoxicillin-clavulanate or amoxicillin 4
  • Amoxicillin-clavulanate can be administered twice daily (875/125 mg every 12 hours) with similar efficacy to three-times-daily dosing 5

Alternative Options (Beta-lactam Allergy)

• TMP-SMX, doxycycline, azithromycin, clarithromycin, or erythromycin 4
• Note that these alternatives may have 20-25% bacteriological failure rates 4

Urinary Tract Infections

Uncomplicated UTIs

• Short-course therapy (3-5 days) with appropriate antibiotics is effective for uncomplicated UTIs 6
• Fluoroquinolones (e.g., ciprofloxacin) are effective but should be reserved for cases where first-line agents cannot be used 6

Special Considerations

Outpatient Parenteral Antimicrobial Therapy (OPAT)

• OPAT is appropriate for various infections including SSTIs, osteomyelitis, pneumonia, complicated UTIs, and endocarditis when oral therapy is not suitable 1
• Patients or caregivers can be trained to self-administer OPAT at home 1

Medication Administration

• Amoxicillin-clavulanate should be taken with meals or snacks to reduce gastrointestinal upset 7
• Patients should be counseled to complete the full course of antibiotics even if feeling better 7

Adverse Effects

• Broad-spectrum antibiotics are associated with increased risk of adverse drug events compared to narrow-spectrum agents 3
• Common antibiotic-related adverse effects include diarrhea, nausea/vomiting/abdominal pain, and vulvovaginal candidiasis 7, 3
• Patients should be advised to contact their physician if diarrhea is severe or lasts more than 2-3 days 7

Common Pitfalls to Avoid

• Using broad-spectrum antibiotics when narrow-spectrum agents would suffice 3, 2
• Prescribing unnecessarily long treatment durations 3, 2
• Failing to obtain cultures in severe infections or when empirical therapy fails 1
• Using macrolide monotherapy in areas with high pneumococcal resistance 1
• Neglecting patient education about completing the full antibiotic course 7