Chapter 129. Staphylococcal Infections (Part 11) ppsx

Chapter 129. Staphylococcal Infections (Part 11) Table 129- 3 Antimicrobial Therapy for Serious Staphylococcal Infections a Sensitivity/Resis tance of Isolate Drug of Choice Alternative( s) Comments Sensitive to penicillin Penicilli n G (4 mU q4h) Nafcillin (2 g q4h) or oxacillin (2 g q4h), cefazolin (2 g q8h), vancomycin (1 g q12h b ) Fewer than 5% of isolates are sensitive to penicillin. Sensitive to Nafcillin Cefazolin (2 Patients with methicillin or oxacillin (2 g q4h) g q8h b ), vancomycin (1 g q12h b ) penicillin allergy can be treated with a cephalosporin if the allergy does not involve an anaphylactic or accelerated reaction; vancomycin is the alternative. Desensitization to β- lactams may be indicated in selected cases of serious infection where maximal bactericidal activity is needed (e.g., prosthetic-valve endocarditis c ). Type A β- lactamase may rapidly hydrolyze cefazolin and reduce its efficacy in endocarditis. Resistant to methicillin Vancom ycin (1 g q12h b ) TMP-SMX (TMP, 5 mg/kg q12h b ), minocyc line or doxycycline(100 mg PO q12h b ), ciprofloxacin (400 mg q12h b ), levofloxacin (500 mg q24h b ), quinupristin/dalfopr istin (7.5 mg/kg q8h), linezolid (600 mg q12h except : 400 mg q12h for Sensitivity testing is necessary before an alternativ e drug is used. Adjunctive drugs (those that should be used only in combination with other antimicrobial agents) include gentamicin (1 mg/kg q8h b ), rifampin (300 mg PO q8h), and fusidic acid (500 uncomplicated skin infections); daptomycin (4– 6 mg/kg q24h b, c ) for bacteremia, endocarditis, and complicated skin infections; tigecycline (100 mg IV once, then 50 mg q12h) for skin and soft tissue infections; investigational drugs: oritavancin, dalbavancin, telavancin mg q8h; not readily available in the United States). Quinupristin/dalfopr istin is bactericidal against methicillin- resistant isolates unless the strain is resistant to erythromycin or clindamycin. The newer quinolones may retain in vitro activity against ciprofloxacin- resistant isolates; resistance may develop duri ng therapy. The efficacy of adjunctive therapy is not well established in many settings. Both linezolid and quinupristin/dalfopr istin have had in vitro activity against most VISA and VRSA strains. See footnote for treatment of prosthetic-valve endocarditis. d Resistant to methicillin with intermediate or complete resistance to vancomycin e Uncertai n Same as for methicillin- resistant strains; check antibiotic susceptibilities Same as for methicillin-resistant strains; check antibiotic susceptibilities. N ot yet known (i.e., empirical therapy) Vancom ycin (1 g q12h) — Empirical therapy is given when the susceptibility of the isolate is not known. Vancomycin with or without an aminoglycoside is recommended for suspected community- or hospital-acquired S. aureus infections because of the increased frequency of methicillin- resistant strains in the community. a Recommendeddosages are for adults with normal renal and hepatic function. Theroute of administration is intravenous unless otherwise indicated. b The dosage must be adjusted inpatients with reduced creatinine clearance. c Daptomycin cannot be used forpneumonia. d For the treatment of prosthetic- valveendocarditis, the addition of gentamicin (1 mg/kg q8h)and rifampin (300 mg PO q8h) is recommended, with adjustment of thegentamicin dosage if the creatinine clearance rate is reduced. e Vancomycin-resistant S. aureus isolates from clinical infectionshave been reported. Source: Modified withpermission of the New England Journal ofMedicine (Lowy, 1998). © 1998 Massachusetts MedicalSociety. All rights reserved. Note:TMP-SMX, trimethoprim-sulfamethoxazole;VISA, vancomycin- intermediate S. aureus;VRSA, vancomycin-resistant S. aureus. . Chapter 129. Staphylococcal Infections (Part 11) Table 129- 3 Antimicrobial Therapy for Serious Staphylococcal Infections a Sensitivity/Resis tance. and fusidic acid (500 uncomplicated skin infections) ; daptomycin (4– 6 mg/kg q24h b, c ) for bacteremia, endocarditis, and complicated skin infections; tigecycline (100 mg IV once,. complicated skin infections; tigecycline (100 mg IV once, then 50 mg q12h) for skin and soft tissue infections; investigational drugs: oritavancin, dalbavancin, telavancin mg q8h; not readily