Empirical Antibiotic Therapy Guidelines

Introduction to Empirical Antibiotics

• The Infectious Diseases Society of America recommends that empirical antibiotics should only be administered in specific clinical scenarios where bacterial infection is highly suspected or confirmed, as inappropriate use contributes to antibiotic resistance without improving patient outcomes 1, 2

Appropriate Indications for Empirical Antibiotics

• For patients with infectious diarrhea, empiric antibiotics are not recommended for most cases of acute watery diarrhea without recent international travel, according to the Infectious Diseases Society of America 1, 3
• Exceptions for diarrhea where empiric antibiotics may be warranted include infants less than 3 months of age with suspected bacterial etiology, immunocompromised patients with severe illness and bloody diarrhea, patients with fever, abdominal pain, bloody diarrhea, and signs of bacillary dysentery, and recent international travelers with body temperatures greater than or equal to 38.5°C and/or signs of sepsis, as recommended by the Infectious Diseases Society of America 1
• For COVID-19 patients, empiric antibiotics are not recommended unless there is clinical suspicion of bacterial superinfection, according to the World Health Organization 2, 4
• The World Health Organization recommends against empiric antibiotics in mild COVID-19, and for moderate COVID-19, antibiotics should only be considered with clinical concern for bacterial pneumonia 2
• For COVID-19 patients with shock, empiric antibiotics may be warranted as part of standard sepsis management, according to the World Health Organization 2
• Patients with clinical features of sepsis should receive prompt empiric broad-spectrum antimicrobial therapy after appropriate cultures are collected, as recommended by the Infectious Diseases Society of America 1
• Empiric antibiotic therapy should be started when there are clinical signs of central venous catheter infection, without waiting for blood culture results, according to the European Society for Medical Oncology 5
• All clinically infected diabetic foot wounds should receive antibiotic therapy, but uninfected wounds should not be treated with antibiotics, as recommended by the Infectious Diseases Society of America 6

Appropriate Antibiotic Selection

• For infectious diarrhea, the Infectious Diseases Society of America recommends fluoroquinolone or azithromycin for adults, and third-generation cephalosporin or azithromycin for children, depending on local susceptibility patterns and travel history 1
• For central venous catheter infections, the European Society for Medical Oncology recommends vancomycin as empiric therapy, with options for daptomycin or fourth-generation cephalosporins, carbapenems, or β-lactam/β-lactamase combinations for severe symptoms 5
• For diabetic foot infections, the Infectious Diseases Society of America recommends considering empiric coverage against MRSA in patients with prior MRSA history, high local MRSA prevalence, or severe infection 6
• For nosocomial pneumonia, the American Thoracic Society recommends piperacillin-tazobactam plus an aminoglycoside 7

Best Practices for Empirical Antibiotic Use

• The American Thoracic Society recommends obtaining appropriate microbiological samples before starting antibiotics, and starting empiric treatment promptly in cases of sepsis, as delays increase mortality 7
• The American Thoracic Society also recommends tailoring empiric therapy to the site of infection, risk factors for multidrug-resistant bacteria, local microbiology and susceptibility patterns, and patient's recent antibiotic exposure 7
• The Infectious Diseases Society of America recommends modifying or discontinuing antibiotics when a clinically plausible organism is identified, and de-escalating therapy based on culture results and clinical response 1, 5

Special Considerations

• The Infectious Diseases Society of America recommends a lower threshold for empiric antibiotics in immunocompromised patients, and adjusting antibiotic dosing based on creatinine clearance in patients with renal impairment 1, 5
• The American Thoracic Society recommends selecting a different antibiotic class in patients with recent antibiotic use, and considering broader empiric coverage for healthcare-associated infections 7