Page 923 - Basic _ Clinical Pharmacology ( PDFDrive )

CHAPTER 51 Clinical Use of Antimicrobial Agents 909

TABLE 51–2 Empiric antimicrobial therapy based on site of infection.

Presumed Site of Infection Common Pathogens Drugs of First Choice Alternative Drugs
Bacterial endocarditis
1
Acute Staphylococcus aureus Vancomycin + ceftriaxone Penicillinase-resistant penicillin +
gentamicin
Subacute Viridans streptococci, enterococci Penicillin + gentamicin Vancomycin + gentamicin
Septic arthritis
Child Haemophilus influenzae, S aureus, Vancomycin + ceftriaxone Vancomycin + ampicillin-sulbactam or
β-hemolytic streptococci ertapenem
Adult S aureus, Enterobacteriaceae, Vancomycin + ceftriaxone Vancomycin + ertapenem, or quinolone
Neisseria gonorrhoeae
Acute otitis media, H influenzae, Streptococcus Amoxicillin Amoxicillin-clavulanate, cefuroxime
sinusitis pneumoniae, Moraxella catarrhalis axetil, TMP-SMZ
Cellulitis S aureus, group A streptococcus Penicillinase-resistant penicillin, Vancomycin, clindamycin, linezolid,
cephalosporin (first-generation) 2 daptomycin
Meningitis
Neonate Group B streptococcus, Escherichia Ampicillin + cephalosporin Ampicillin + aminoglycoside,
coli, Listeria (third-generation) chloramphenicol, meropenem
Child H influenzae, pneumococcus, Ceftriaxone or cefotaxime ± Chloramphenicol, meropenem
meningococcus vancomycin 3
Adult Pneumococcus, meningococcus Ceftriaxone, cefotaxime Vancomycin + ceftriaxone or cefotaxime 3
Peritonitis due to Coliforms, Bacteroides fragilis Metronidazole + cephalosporin Carbapenem, tigecycline
ruptured viscus (third-generation), piperacillin/
tazobactam
Pneumonia
Neonate As in neonatal meningitis
Child Pneumococcus, S aureus, Ceftriaxone, cefuroxime, Ampicillin-sulbactam
H influenzae cefotaxime
4
Adult Pneumococcus, Mycoplasma, Outpatient: Macrolide, Outpatient: Quinolone
(community-acquired) Legionella, H influenzae, S aureus, amoxicillin, tetracycline
Chlamydophila pneumonia,
coliforms
4
Inpatient: Macrolide + Inpatient: Doxycycline + cefotaxime,
cefotaxime, ceftriaxone, ceftriaxone, ertapenem, or ampicillin;
ertapenem, or ampicillin respiratory quinolone 5
Septicemia 6 Any Vancomycin + cephalosporin (third-generation) or piperacillin/tazobactam or
imipenem or meropenem
Septicemia with Any Antipseudomonal penicillin + aminoglycoside; ceftazidime; cefepime;
granulocytopenia imipenem or meropenem; consider addition of systemic antifungal therapy if
fever persists beyond 5 days of empiric therapy
1 See footnote 9, Table 51–1.
2
See footnote 2, Table 51–1.
3 When meningitis with penicillin-resistant pneumococcus is suspected, empiric therapy with this regimen is recommended.
4
Erythromycin, clarithromycin, or azithromycin (an azalide) may be used.
5 Quinolones used to treat pneumonococcal infections include levofloxacin, moxifloxacin, and gemifloxacin.
6
Adjunctive immunomodulatory drugs such as drotrecogin-alfa can also be considered for patients with severe sepsis.

determine the cause of failure. Errors in susceptibility testing are can be done to maximize it. For example, are adequate numbers
rare, but the original results should be confirmed by repeat test- of granulocytes present and is undiagnosed immunodeficiency,
ing. Drug dosing and absorption should be scrutinized and tested malignancy, or malnutrition present? The presence of abscesses
directly using serum measurements, pill counting, or directly or foreign bodies should also be considered. Finally, culture and
observed therapy. susceptibility testing should be repeated to determine whether
The clinical data should be reviewed to determine whether superinfection has occurred with another organism or whether the
the patient’s immune function is adequate and, if not, what original pathogen has developed drug resistance.