Table 3.
Recommended antimicrobial therapy for specific pathogens
| Organism | Preferred Antimicrobial(s) | Alternative Antimicrobial(s) |
|---|---|---|
| Streptococcus pneumoniae | ||
| Penicillin-nonresistant; MIC<2 μg/mL | Penicillin G, amoxicillin | Macrolide, cephalosporins (oral [cefpodoxime, cefprozil, cefuroxime, cefdinir, cefditoren] or parenteral [cefuroxime, ceftriaxone, cefotaxime]), clindamycin, doxycycline, respiratory fluoroquinolonea |
| Penicillin-resistant; MIC≥2 μg/mL | Agents chosen based on susceptibility, including cefotaxime, ceftriaxone, fluoroquinolone | Vancomycin, linezolid, high-dose amoxicillin (3 g/d with penicillin MIC≤4 μg/mL) |
| Haemophilus influenzae | ||
| Non–β-lactamase–producing | Amoxicillin | Fluoroquinolone, doxycycline, azithromycin, clarithromycinb |
| β-Lactamase–producing | Second- or third-generation cephalosporin, amoxicillin-clavulanate | Fluoroquinolone, doxycycline, azithromycin, clarithromycinb |
| Mycoplasma pneumoniae/Chlamydophila pneumoniae | Macrolide, a tetracycline | Fluoroquinolone |
| Legionella spp | Fluoroquinolone, azithromycin | Doxycycline |
| Chlamydophila psittaci | A tetracycline | Macrolide |
| Coxiella burnetii | A tetracycline | Macrolide |
| Francisella tularensis | Doxycycline | Gentamicin, streptomycin |
| Yersinia pestis | Streptomycin, gentamicin | Doxycycline, fluoroquinolone |
| Bacillus anthracis (inhalation) | Ciprofloxacin, levofloxacin, doxycycline (usually with second agent) | Other fluoroquinolones; β-lactam, if susceptible; rifampin; clindamycin; chloramphenicol |
| Enterobacteriaceae | Third-generation cephalosporin, carbapenemc (preferred drug if extended-spectrum β-lactamase producer) |
β-lactam/β-lactamase inhibitor,d fluoroquinolone |
| Pseudomonas aeruginosa | Antipseudomonal β-lactame plus (ciprofloxacin or levofloxacinf or aminoglycoside) | Aminoglycoside plus (ciprofloxacin or levofloxacinf) |
| Burkholderia pseudomallei | Carbapenem, ceftazidime | Fluoroquinolone, TMP-SMX |
| Acinetobacter spp | Carbapenem | Cephalosporin-aminoglycoside, ampicillin-sulbactam, colistin |
| Staphylococcus aureus | ||
| Methicillin-susceptible | Antistaphylococcal penicilling | Cefazolin, clindamycin |
| Methicillin-resistant | Vancomycin or linezolid | TMP-SMX |
| Bordetella pertussis | Macrolide | TMP-SMX |
| Anaerobe (aspiration) | β-Lactam/β-lactamase inhibitor,d clindamycin | Carbapenem |
| Influenza virus | Oseltamivir or zanamivir | |
| Mycobacterium tuberculosis | Isoniazid plus rifampin plus ethambutol plus pyrazinamide | Refer to Ref.57 for specific recommendations |
| Coccidioides spp | For uncomplicated infection in a normal host, no therapy generally recommended; for therapy, itraconazole, fluconazole | Amphotericin B |
| Histoplasmosis | Itraconazole | Amphotericin B |
| Blastomycosis | Itraconazole | Amphotericin B |
Choices should be modified based on susceptibility test results and advice from local specialists. Refer to local references for appropriate doses.
Abbreviations: MIC, minimum inhibitory concentration; TMP-SMX, trimethoprim-sulfamethoxazole.
Levofloxacin, moxifloxacin, gemifloxacin (not a first-line choice for penicillin susceptible strains); ciprofloxacin is appropriate for Legionella and most gram-negative bacilli (including H influenza).
Azithromycin is more active in vitro than clarithromycin for H influenza.
Imipenem-cilastatin, meropenem, ertapenem.
Piperacillin-tazobactam for gram-negative bacilli; ticarcillin-clavulanate, ampicillin-sulbactam, or amoxicillin-clavulanate.
Ticarcillin, piperacillin, ceftazidime, cefepime, aztreonam, imipenem, meropenem.
750 mg/d.
Nafcillin, oxacillin flucloxacillin.
From Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007;44:S27–72; with permission.