Chapter 129. Staphylococcal Infections (Part 11) ppsx

methicillin or oxacillin 2 g q4h g q8hb, vancomycin 1 g q12hb penicillin allergy can be treated with a cephalosporin if the allergy does not involve an anaphylactic or accelerated react

Chapter 129 Staphylococcal Infections

(Part 11)

Table 129-3 Antimicrobial Therapy for Serious Staphylococcal Infectionsa

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 q12hb)

Fewer than 5% of isolates are sensitive to penicillin

Sensitive to Nafcillin Cefazolin (2 Patients with

methicillin or oxacillin (2 g

q4h)

g q8hb), vancomycin (1 g q12hb)

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 endocarditisc) Type

A β-lactamase may

rapidly hydrolyze cefazolin and reduce its efficacy

in endocarditis

Resistant to

methicillin

Vancom ycin (1 g q12hb)

TMP-SMX (TMP, 5 mg/kg q12hb),

minocycline or doxycycline(100

mg PO q12hb), ciprofloxacin (400

mg q12hb), levofloxacin (500

mg q24hb), quinupristin/dalfopr istin (7.5 mg/kg q8h), linezolid (600

mg q12h except:

400 mg q12h for

Sensitivity testing is necessary before an alternative drug is used Adjunctive drugs (those that should

be used only in combination with other antimicrobial agents) include gentamicin (1 mg/kg q8hb), rifampin (300 mg

PO q8h), and fusidic acid (500

uncomplicated skin

infections);

daptomycin (4–6

mg/kg q24hb, 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 during 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

vancomycine

Uncertai

n

Same as for methicillin-resistant strains; check antibiotic

susceptibilities

Same as for methicillin-resistant strains; check antibiotic

susceptibilities

Not 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

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

vancomycin-intermediate S aureus;VRSA, vancomycin-resistant S aureus