|
Organism |
Preferred antimicrobial(s) |
Alternative antimicrobial(s) |
|
Streptococcus pneumoniae | ||
|
Penicillin nonresistant; MIC <2 microg/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 microg/mL |
Agents chosen on the basis of susceptibility, including cefotaxime, ceftriaxone, fluoroquinolone |
Vancomycin, linezolid, high-dose amoxicillin (3 g/d with penicillin MIC ≤4 microg/mL) |
|
Haemophilus influenzae | ||
|
Non–beta-lactamase producing |
Amoxicillin |
Fluoroquinolone, doxycycline, azithromycin, clarithromycinb |
|
Beta-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 a second agent) |
Other fluoroquinolones; beta-lactam, if susceptible; rifampin; clindamycin; chloramphenicol |
|
Enterobacteriaceae |
Third-generation cephalosporin, carbapenemc (drug of choice if extended-spectrum beta-lactamase producer) |
Beta-lactam/beta-lactamase inhibitor,d fluoroquinolone |
|
Pseudomonas aeruginosa |
Antipseudomonal beta-lactame plus (ciprofloxacin or levofloxacinf or aminoglycoside) |
Aminoglycoside plus (ciprofloxacin or levofloxacinf) |
|
Burkholderia pseudomallei |
Carbapenem, ceftazidime |
Fluoroquinolone, sulfamethoxazole/trimethoprim |
|
Acinetobacter spp |
Carbapenem |
Cephalosporin-aminoglycoside, ampicillin/sulbactam, colistin |
|
Staphylococcus aureus | ||
|
Methicillin susceptible |
Antistaphylococcal penicilling |
Cefazolin, clindamycin |
|
Methicillin resistant |
Vancomycin or linezolid |
Sulfamethoxazole/trimethoprim |
|
Bordetella pertussis |
Macrolide |
Sulfamethoxazole/trimethoprim |
|
Anaerobe (aspiration) |
Beta-lactam/beta-lactamase inhibitor,d clindamycin |
Carbapenem |
|
Influenza virus |
Oseltamivir or zanamivir |
|
|
Mycobacterium tuberculosis |
Isoniazid plus rifampin plus ethambutol plus pyrazinamide |
|
|
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 on the basis of susceptibility test results and advice from local specialists. Refer to local references for appropriate doses. | ||
|
a Levofloxacin, moxifloxacin, gemifloxacin (not a first-line choice for penicillin susceptible strains); ciprofloxacin is appropriate for Legionella and most gram-negative bacilli (including Haemophilus influenzae). b Azithromycin is more active in vitro than clarithromycin for H influenzae. c Imipenem/cilastatin, meropenem, ertapenem. d Piperacillin/tazobactam for gram-negative bacilli, ticarcillin/clavulanate, ampicillin/sulbactam, or amoxicillin/clavulanate. e Ticarcillin, piperacillin, ceftazidime, cefepime, aztreonam, imipenem, meropenem. f 750 mg daily. g Nafcillin, oxacillin, flucloxacillin. | ||
|
INN, international nonproprietary name; MIC, minimum inhibitory concentration. | ||