Antibiotic Treatment for Community-Acquired Pneumonia

Treatment Algorithm Based on Severity and Setting

The British Thoracic Society recommends combination therapy with amoxicillin plus a macrolide (erythromycin or clarithromycin) orally, or alternatively, levofloxacin 750 mg once daily as monotherapy for a 72-year-old female with community-acquired pneumonia requiring hospitalization 1, 2
The British Thoracic Society suggests that most patients can be adequately treated with oral antibiotics 1
The preferred first-line combination therapy is amoxicillin PLUS a macrolide (erythromycin or clarithromycin) for patients requiring hospital admission for clinical reasons, providing coverage for both typical bacteria and atypical pathogens 1, 3
Levofloxacin 750 mg orally once daily is an appropriate alternative, particularly for patients intolerant of penicillins or macrolides 1

The British Thoracic Society recommends immediate parenteral antibiotics for severe pneumonia, with a preferred regimen of intravenous co-amoxiclav OR second-generation cephalosporin (cefuroxime) OR third-generation cephalosporin (cefotaxime or ceftriaxone) PLUS intravenous macrolide (clarithromycin or erythromycin) 3
The treatment duration is 10 days for microbiologically undefined severe pneumonia, and extended to 14-21 days if Legionella, Staphylococcus aureus, or Gram-negative enteric bacilli are suspected or confirmed 2, 3

The British Thoracic Society recommends the oral route for non-severe pneumonia unless contraindications exist, and switching from IV to oral once clinical improvement occurs, temperature has been normal for 24 hours, and no contraindication to oral route exists 2, 3

The Infectious Diseases Society of America recommends piperacillin-tazobactam 4.5 g IV q6h, OR cefepime 2 g IV q8h for low-risk HAP without MRSA risk factors 4, 6
MRSA coverage is required if prior IV antibiotic use within 90 days, unit MRSA prevalence >20% or unknown, or high mortality risk, and vancomycin 15 mg/kg IV q8-12h (target trough 15-20 mg/mL) OR linezolid 600 mg IV q12h should be added 4, 5, 6