Empirical therapy for native joint septic arthritis when Gram stain is not available or does not demonstrate any organisms

The regimens below are recommended for native joint septic arthritis when Gram stain of a joint aspirate is not available, does not demonstrate any organisms, or morphology is not reported.

For patients with sepsis or septic shock, treat as for Sepsis or septic shock associated with a bone or joint source.

For adults and children 4 years or older at low risk of methicillin-resistant Staphylococcus aureus (MRSA) infection (for risk factors, see Risk factors for infection with methicillin-resistant Staphylococcus aureus), use:

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 in Intravenous to oral switch and duration of therapy for native joint septic arthritis. flucloxacillin flucloxacillin flucloxacillin

For children younger than 4 years, cefazolin is the preferred empirical antibiotic as Kingella kingae and Staphylococcus aureus are the most common pathogens; use:

cefazolin 50 mg/kg up to 2 g intravenously, 8-hourly. See advice in Intravenous to oral switch and duration of therapy for native joint septic arthritis. cefazolin

For patients who have had a nonsevere (immediate or delayed) hypersensitivity reaction to a penicillin, use:

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 in Intravenous to oral switch and duration of therapy for native joint septic arthritis. cefazolin cefazolin cefazolin

For patients who have had a severe immediate hypersensitivity reaction to a penicillin, cefazolin (at the dosage above) can be considered if a beta-lactam antibiotic is strongly preferred (for considerations, see Severe immediate hypersensitivity: Implications of cross-reactivity between penicillins and cephalosporins).

For adults and children 4 years and older who have had a severe immediate¹ hypersensitivity reaction to a penicillin in whom cefazolin is not used, or for adults and children older than 4 years who have had a severe delayed² hypersensitivity reaction to a penicillin, use:

vancomycin intravenously; for initial dosing, see Intermittent vancomycin dosing for noncritically ill adults or Intermittent vancomycin dosing for young infants and children. See advice in Intravenous to oral switch and duration of therapy for native joint septic arthritis. vancomycin vancomycin vancomycin

For children younger than 4 years who have had a severe immediate¹ hypersensitivity reaction to a penicillin in whom cefazolin is not used, or for children younger than 4 years who have had a severe delayed² hypersensitivity reaction to a penicillin, seek expert advice.

If the patient is at increased risk of MRSA infection, add vancomycin to flucloxacillin or cefazolin.

In some regions, based on local MRSA susceptibility patterns, clindamycin is a suitable alternative to vancomycin; use:

clindamycin 600 mg (child: 15 mg/kg up to 600 mg) intravenously, 8-hourly. See advice in Intravenous to oral switch and duration of therapy for native joint septic arthritis.

Modify therapy according to the results of culture and susceptibility testing. For suggested regimens, see:

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