What are the guidelines for antibiotic (Abx) use?

Guidelines for Antibiotic Use

Antibiotics should be used only when necessary, with the right drug at the right dose for the right duration for a specific condition, to optimize clinical outcomes while minimizing antimicrobial resistance. 1

General Principles of Appropriate Antibiotic Use

Indications for Antibiotic Therapy

• Antibiotics should be administered promptly to all neutropenic patients at the onset of fever, as the progression of infection can be rapid 2
• Afebrile neutropenic patients with signs or symptoms compatible with infection should also receive empirical antibiotic therapy 2
• Antibiotics should only be used after a treatable infection has been recognized or if there is a high degree of suspicion of an infection 2
• For uncomplicated acute infections such as uncomplicated appendicitis or cholecystitis, single doses have the same impact as multiple doses if source control is adequate 2

Duration of Therapy

• In patients with complicated intra-abdominal infections (cIAI) undergoing adequate source control, a short course of antibiotic therapy (3-5 days) is recommended 2
• For community-acquired pneumonia, shorter courses (5 days) have shown similar efficacy to longer courses (10 days) in appropriate patients 3
• The duration of antibiotic treatment for parapneumonic effusions depends on the adequacy of drainage and clinical response, with most children requiring 2-4 weeks of treatment 2

Antibiotic Selection Considerations

• Base empiric antibiotic regimens on:
  1. Clinical condition of the patient
  2. Individual risk for infection by resistant pathogens
  3. Local resistance epidemiology 2
• For neutropenic patients, consider risk stratification (high vs. low risk) to guide initial antibiotic selection 2
• When blood or pleural fluid bacterial culture identifies a pathogenic isolate, antibiotic susceptibility should determine the antibiotic regimen 2

Specific Antibiotic Recommendations by Condition

Febrile Neutropenia

• High-risk patients: Use intravenous antibiotics; options include:
  • Monotherapy with cefepime, ceftazidime, or a carbapenem 2, 4
  • Two-drug combinations with vancomycin plus cefepime, ceftazidime, or a carbapenem, with or without an aminoglycoside 2
• Low-risk patients: May be treated with either IV or oral antibiotics 2
• Cefepime is indicated for empiric therapy in febrile neutropenic patients at 2g IV every 8 hours for 7 days or until resolution of neutropenia 4

Community-Acquired Pneumonia

• Levofloxacin 750mg daily for 5 days has shown similar efficacy to 500mg daily for 10 days 3
• For pediatric community-acquired pneumonia with parapneumonic effusion:
  • Small effusions: Treat with antibiotics alone
  • Moderate-large effusions: Consider drainage options (chest tube alone, chest tube with fibrinolytics, or VATS) 2

Intra-Abdominal Infections

• For complicated intra-abdominal infections:
  • Short course (3-5 days) after adequate source control 2
  • Cefepime 2g IV every 8-12 hours for 7-10 days (in combination with metronidazole) 4

Acute Bacterial Sinusitis

• Options include:
  • Amoxicillin/clavulanate (1.75 to 4 g/250 mg per day)
  • Amoxicillin (1.5 to 4 g/day)
  • Cefpodoxime proxetil, cefuroxime axetil, or cefdinir 2
• For patients with β-lactam allergies: TMP/SMX, doxycycline, azithromycin, clarithromycin, erythromycin, or telithromycin (note: 20-25% bacteriologic failure rates possible) 2

Monitoring and Adjustment of Therapy

Response Assessment

• Patients not responding to initial therapy after 48-72 hours should be managed by:
  1. Clinical and laboratory reassessment of illness severity
  2. Imaging evaluation to assess extent and progression of infection
  3. Further investigation to identify persistent pathogens, resistance development, or secondary infections 2

De-escalation and Discontinuation

• Always try to de-escalate/streamline antibiotic treatment according to clinical situation and microbiological results 5
• Stop unnecessarily prescribed antibiotics once the absence of infection is likely 5
• For patients with ongoing signs of peritonitis or systemic illness beyond 5-7 days of antibiotic treatment, diagnostic investigation is warranted 2

Antimicrobial Stewardship Considerations

Preventing Resistance

• Optimal antibiotic dosing schemes should be used, with attention to adverse effects 2
• Avoid antibiotics with higher likelihood of promoting drug resistance when possible 5
• Drain infected foci quickly and remove all potentially or proven infected devices to control the infection source 5
• The inappropriate use of antibiotics is a key driver of antimicrobial resistance 2

Special Considerations

• For multidrug-resistant gram-negative bacilli, treatment should be tailored based on susceptibility patterns 2
• For pan-resistant organisms, select antibiotics with the least resistance based on MICs relative to breakpoints, and prioritize optimal source control 2

Common Pitfalls to Avoid

• Treating fever without identifying the source: Use antibiotics to treat infections, not just fever; investigate the root cause of fever prior to starting treatment 5
• Prolonging therapy unnecessarily: Prolonged antibiotic use increases selection pressure for resistant organisms 1
• Inadequate dosing: Altering the timing of antibiotic doses can lead to suboptimal drug concentrations, creating ideal conditions for resistant bacteria to survive and multiply 1
• Failing to obtain appropriate cultures: Get appropriate microbiological samples before antibiotic administration and carefully interpret the results 5
• Overlooking source control: Source control should always be a priority to optimize outcomes and shorten antibiotic treatment durations 2

By following these guidelines, clinicians can optimize antibiotic use to achieve the best outcomes for patients while minimizing the development of antimicrobial resistance.