What are the names and indications of all antibiotics used in Community-Acquired Pneumonia (CAP) management?

Antibiotics Used in Community-Acquired Pneumonia (CAP) Management

Outpatient Treatment - Previously Healthy Adults

For previously healthy adults without comorbidities or risk factors for drug-resistant S. pneumoniae, macrolides (azithromycin, clarithromycin, or erythromycin) are the first-line antibiotics, though this recommendation is limited to areas where macrolide resistance is <25%. 1, 2

• Amoxicillin 1 g three times daily is now the preferred first-line therapy for healthy adults according to the most recent guidelines 2
• Doxycycline 100 mg twice daily serves as an acceptable alternative 1, 2
• Macrolides include:
  • Azithromycin 500 mg on day 1, then 250 mg daily 1, 2, 3
  • Clarithromycin 500 mg twice daily 1, 2, 3
  • Erythromycin (though clarithromycin preferred due to fewer adverse events) 1

Important caveat: In regions with high rates (≥25%) of macrolide-resistant S. pneumoniae, avoid macrolide monotherapy and use alternative agents 1, 2

Outpatient Treatment - Adults with Comorbidities

For adults with comorbidities (chronic heart, lung, liver, or renal disease; diabetes; alcoholism; malignancies; immunosuppression; or recent antibiotic use within 3 months), either respiratory fluoroquinolone monotherapy or β-lactam plus macrolide combination is strongly recommended. 1, 2

Respiratory Fluoroquinolones (Monotherapy Option):

• Levofloxacin 750 mg daily 1, 2, 4
• Moxifloxacin 1, 2
• Gemifloxacin 1, 2

β-lactam Plus Macrolide Combination:

• High-dose amoxicillin (1 g three times daily) or amoxicillin-clavulanate (2 g twice daily) plus a macrolide 1, 2
• Alternative β-lactams include:
  • Ceftriaxone 1
  • Cefpodoxime 1
  • Cefuroxime 500 mg twice daily 1
• Doxycycline can substitute for the macrolide 1, 2

Inpatient Non-ICU Treatment

For hospitalized patients not requiring ICU admission, either respiratory fluoroquinolone monotherapy or β-lactam plus macrolide combination is strongly recommended. 1, 2

First-Line Options:

• Respiratory fluoroquinolone monotherapy (levofloxacin or moxifloxacin) 1, 2
• β-lactam plus macrolide combination 1, 2:
  • Preferred β-lactams: cefotaxime, ceftriaxone, ampicillin 1
  • Ertapenem for selected patients with risk factors for gram-negative pathogens (excluding Pseudomonas) 1
  • Ampicillin-sulbactam 2
  • Ceftaroline 2

Alternative:

• β-lactam plus doxycycline 1, 2

Penicillin Allergy:

• Respiratory fluoroquinolone should be used 1, 5

Inpatient ICU Treatment

For critically ill patients requiring ICU admission, combination therapy with a β-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam) plus either azithromycin or a respiratory fluoroquinolone is strongly recommended. 1, 2

Standard Severe CAP:

• β-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam) PLUS
• Azithromycin OR respiratory fluoroquinolone (levofloxacin or moxifloxacin) 1, 2

Penicillin-Allergic ICU Patients:

• Respiratory fluoroquinolone plus aztreonam 1, 5

Special Pathogen Coverage

Pseudomonas aeruginosa Risk Factors:

For patients with risk factors for Pseudomonas infection (structural lung disease, recent hospitalization, recent broad-spectrum antibiotics), use an antipseudomonal β-lactam plus either a fluoroquinolone or an aminoglycoside-based regimen. 1, 2

• Antipseudomonal β-lactams:

  • Piperacillin-tazobactam 1, 2
  • Cefepime 1
  • Imipenem 1
  • Meropenem 1

• Plus one of:

  • Ciprofloxacin or levofloxacin 750 mg 1, 2
  • Aminoglycoside plus azithromycin 1
  • Aminoglycoside plus antipneumococcal fluoroquinolone 1

Community-Acquired MRSA:

For suspected or confirmed community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA), add vancomycin or linezolid to the regimen. 1, 2, 5

• Vancomycin 1, 2, 5
• Linezolid 1, 2, 5

Treatment Duration

The standard duration for uncomplicated CAP is 5-7 days, with patients requiring clinical stability (afebrile for 48-72 hours with ≤1 sign of clinical instability) before discontinuation. 2, 5

• Minimum 5 days with clinical stability criteria met 2, 5
• Traditional 7-10 day courses for more severe infections 1
• Longer courses may be needed for specific pathogens or complications 2

Critical Implementation Points

The first antibiotic dose should be administered in the emergency department for hospitalized patients to reduce mortality. 2, 5

• Switch from IV to oral therapy when hemodynamically stable, clinically improving, able to take oral medications, and have normal GI function 2, 5
• Adjust therapy when culture results become available 2
• Consider local resistance patterns, particularly for S. pneumoniae 1, 5, 6
• Avoid macrolide monotherapy in areas with high resistance rates to prevent treatment failure 2
• Recent antibiotic exposure increases risk of resistant organisms and should guide antibiotic selection 2