What treatment is recommended for bacterial or fungal infections?

Treatment Recommendations for Bacterial and Fungal Infections

The treatment of bacterial and fungal infections requires targeted antimicrobial therapy based on the suspected or confirmed pathogen, with empiric broad-spectrum antibiotics recommended for severe infections while awaiting culture results.

Bacterial Infections

Empiric Therapy for Suspected Bacterial Infections

• For severe infections/sepsis:
  • Start broad-spectrum antibiotics within 1 hour of recognition 1
  • Use combination therapy (at least two antibiotics of different classes) for initial management of septic shock 1
  • Consider an extended-spectrum penicillin (e.g., piperacillin/tazobactam) or extended-spectrum cephalosporin (e.g., ceftazidime, ceftriaxone) plus an aminoglycoside 1

Site-Specific Bacterial Infections

Urinary Tract Infections

• For uncomplicated UTIs: Oral fluoroquinolones or cephalexin 1g twice daily for 7-10 days 2
• For complicated UTIs/pyelonephritis with sepsis: Broad-spectrum parenteral antibiotics such as:
  • Third-generation cephalosporins (e.g., ceftriaxone 1-2g IV every 24 hours)
  • Piperacillin/tazobactam (3.375-4.5g IV every 8 hours) 3

Skin and Soft Tissue Infections

• For streptococcal/staphylococcal infections:
  • Cephalexin 500mg twice daily or dicloxacillin 500mg four times daily 4
  • For MRSA concerns: Consider vancomycin or newer agents based on susceptibility

Bacterial Keratitis

• For central or severe keratitis:
  • Loading dose of topical antibiotics every 5-15 minutes followed by hourly application
  • Single-drug therapy with a fluoroquinolone or combination therapy with fortified antibiotics 1

Duration of Therapy

• Standard duration: 7-10 days for most serious infections 1
• Consider shorter courses (5-7 days) for patients with rapid clinical resolution 1
• Longer courses appropriate for:
  • Slow clinical response
  • Undrainable foci of infection
  • Staphylococcus aureus bacteremia
  • Immunocompromised patients 1

Fungal Infections

Candidiasis

• For fluconazole-susceptible Candida infections:

  • Oral fluconazole 200mg (3mg/kg) daily for 2 weeks 1

• For fluconazole-resistant C. glabrata:

  • Amphotericin B deoxycholate 0.3-0.6mg/kg daily for 1-7 days OR
  • Oral flucytosine 25mg/kg 4 times daily for 7-10 days 1

• For C. krusei:

  • Amphotericin B deoxycholate 0.3-0.6mg/kg daily for 1-7 days 1

• For oropharyngeal candidiasis:

  • Mild: Clotrimazole troches 10mg 5 times daily OR miconazole mucoadhesive buccal 50mg tablet daily for 7-14 days
  • Moderate to severe: Oral fluconazole 100-200mg daily for 7-14 days 1

Invasive Fungal Infections

• For most patients with fungal endocarditis:

  • Surgical intervention in conjunction with antifungal agents
  • Early consultation with infectious disease, cardiology, and cardiac surgery services 1

• For disseminated fungal infections:

  • Amphotericin B after 4-7 days of persistent fever despite broad-spectrum antibiotics 1
  • Consider adding 5-fluorocytosine (100-150mg/kg/day divided every 6 hours) to amphotericin B for Candida endocarditis 1

Special Populations

Immunocompromised Patients

• For neutropenic patients with fever:
  • Broad-spectrum antibiotics are recommended 1
  • Consider temporary discontinuation of bispecific antibodies during active bacterial treatment until infection resolution 1
  • Anti-bacterial prophylaxis (e.g., levofloxacin) recommended for patients with prolonged neutropenia or history of recurrent bacterial infections 1

Sepsis Management

• Initial resuscitation:

  • Begin fluid resuscitation with 30mL/kg crystalloid for hypotension or lactate ≥4mmol/L
  • Target mean arterial pressure of 65mmHg in patients requiring vasopressors 1

• Source control:

  • Identify and address source of infection within 12 hours
  • Remove infected devices after establishing alternative access 1, 3

Monitoring and De-escalation

• Assess antibiotic regimen daily for de-escalation opportunities 1
• De-escalate to targeted therapy once culture and susceptibility results are available (typically within 48-72 hours) 3
• Consider procalcitonin levels to support shortening duration of antimicrobial therapy 1

Common Pitfalls and Caveats

1. Delayed treatment: Each hour delay in appropriate antibiotic administration increases mortality in septic patients
2. Inadequate source control: Failure to identify and control the source of infection can lead to persistent infection
3. Inappropriate de-escalation: Continuing broad-spectrum antibiotics unnecessarily promotes antimicrobial resistance
4. Overlooking fungal infections: Consider empiric antifungal therapy in immunocompromised patients with persistent fever despite broad-spectrum antibiotics
5. Neglecting drug interactions and monitoring: Particularly important with aminoglycosides and vancomycin, which require therapeutic drug monitoring

Remember that early, appropriate antimicrobial therapy and adequate source control are the cornerstones of successful treatment of bacterial and fungal infections.