Initial therapy for MSSA native bone or joint infection

The regimens below are recommended for adults and children with osteomyelitis of native bone or septic arthritis of a native joint, when infection is caused by methicillin-susceptible Staphylococcus aureus (MSSA).

To treat MSSA osteomyelitis or septic arthritis in adults and children, use initiallyPreiss, 2020:

flucloxacillin 2 g (child: 50 mg/kg up to 2 g) intravenously, 6-hourly. For dosage adjustment in adults with kidney impairment, see flucloxacillin intravenous dosage adjustment. See advice on modification and duration of therapy. flucloxacillin flucloxacillin flucloxacillin

For adults and children who have had a nonsevere (immediate or delayed) or a severe immediate¹ hypersensitivity reaction to a penicillin, use initially:

cefazolin 2 g (child: 50 mg/kg up to 2 g) intravenously, 8-hourly. For dosage adjustment in adults with kidney impairment, see cefazolin dosage adjustment. See advice on modification and duration of therapy. cefazolin cefazolin cefazolin

For children and nonbacteraemic adults who have had a severe delayed² hypersensitivity reaction to a penicillin, whose infection is caused by confirmed lincosamide-susceptible MSSA, use:

clindamycin 600 mg (child: 15 mg/kg up to 600 mg) intravenously, 8-hourly³; see advice on modification and duration of therapy. clindamycin clindamycin clindamycin

Avoid clindamycin monotherapy in adults with S. aureus bacteraemia; use vancomycin (as below) instead.

For adults and children who have had a severe delayed² hypersensitivity reaction to a penicillin whose infection is caused by lincosamide-resistant MSSA, use:

vancomycin intravenously; for initial dosing, see Intermittent vancomycin dosing for noncritically ill adults or Intermittent vancomycin dosing for young infants and children. See also advice on modification and duration of therapy. vancomycin vancomycin vancomycin

¹ Severe immediate hypersensitivity reactions include anaphylaxis, compromised airway, airway angioedema, hypotension and collapse.Return

² Severe delayed hypersensitivity reactions include cutaneous adverse drug reactions (eg drug rash with eosinophilia and systemic symptoms [DRESS], Stevens–Johnson syndrome/toxic epidermal necrolysis [SJS/TEN], severe blistering or desquamative rash), and significant internal organ involvement (eg acute interstitial nephritis).Return

³ There are more clinical and microbiological data to support the use of clindamycin than lincomycin. Intravenous lincomycin can be used at the same dosage if clindamycin is unavailable or if a local protocol recommends its use.Return