Septic Arthritis of Native Joints Organism-Specific Therapy

Organism-specific regimens for septic arthritis(SA) of native joints are provided below, including those for methicillin-sensitive and methicillin-resistant Staphylococcus aureus, streptococci, gram-negative rods, Pseudomonas, and Neisseria gonorrhoeae. ^{[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]}

Candida auris was recognized in 2007 as a rapidly spreading nosocomial infection that can quickly spread throughout a healthcare facility by avid adherence to all types of surfaces including the skin of patients and healthcare workers, resulting in a variety of serious infections. The COVID-19 pandemic has facilitated its spread. 

Specific antibiotic therapy should not be switched from the IV to the PO route until there is adequate documentation that the infection is responding appropriately. It appears that monitoring various inflammatory markers (such as CRP and proclcitonin) is more valid for this than WBC counts or vital signs. ^[11]

Please see Septic Arthritis.

Methicillin-sensitive Staphylococcus aureus (MSSA)

Medications given for MSSA include the following:

• Nafcillin 2 g IV q4h for ≥ 3wk or

• Cefazolin 2 g IV q8h for ≥ 3wk or

• Ceftriaxone 1 g IV q24h for ≥ 3wk or

• Vancomycin 15 mg/kg q12h for ≥ 3wk (if patient truly is allergic to penicillin)*

Methicillin-resistant S aureus (MRSA)

Medications given for MRSA include the following:

• Vancomycin 15 mg/kg q12h for ≥ 3wk * or

• Linezolid 600 mg IV or PO q12h for ≥ 3wk or

• Daptomycin 6-12mg/kg IV q24h for ≥ 3wk

Penicillin-sensitive streptococci (minimal inhibitory concentration [MIC] < 4 µg/mL)

Medications given for penicillin-sensitive streptococci (minimal inhibitory concentration [MIC] < 4 µg/mL) include the following:

• Ampicillin 2 g IV q4h for ≥ 2wk or

• Ceftriaxone 1-2 g IV q24h for ≥ 2wk or

• Vancomycin  15 mg/kg q12h for ≥ 2wk (see below for caveat)

Penicillin-resistant Streptococcus pneumoniae (MIC ≥ 4 µg/mL)

Medications given for penicillin-resistant Streptococcus pneumoniae (MIC ≥ 4 µg/mL) include the following:

• Ceftriaxone 1-2 g IV q12h for ≥ 2wk or

• Vancomycin 15 mg/kg q12h for ≥ 2wk or

• Levofloxacin 750 mg IV or PO q24h for ≥ 2wk

Gram-negative rods (other than Pseudomonas)

Medications given for gram-negative rods (other than Pseudomonas) include the following:

• Ceftriaxone 1-2 g IV q24h for ≥ 3wk or

• Ciprofloxacin 400 mg IV or  500 mg PO q12h for ≥ 3wk or

• Levofloxacin 500 mg IV or PO q24h for ≥ 3wk

Pseudomonas aeruginosa

Medications given for Pseudomonas aeruginosa include the following:

• Cefepime 2 g IV q8h plus gentamicin or tobramycin 5 mg/kg IV q24h for ≥ 3wk or

• Piperacillin-tazobactam 3.375-4.5 g IV q6h plus  gentamicin or tobramycin 5 mg/kg IV q24h for ≥ 3wk or

• Aztreonam 1-2 g IV q8h plus gentamicin or tobramycin 5 mg/kg IV q24h for ≥ 3wk

Neisseria gonorrhoeae

Medications given for Neisseria gonorrhoeae include the following:

• Ceftriaxone 1-2 g IV or IM q24h for 2wk or
• Cefixime 400 mg PO BID for 2wk or
• Cefpodoxime 400 mg PO BID for 2wk or
• Ciprofloxacin  400 mg IV or 500 mg PO q12h for 2wk (if organism is susceptible)

Special considerations

Special considerations include the following:

• *Severely ill patients frequently exhibit fluctuating renal function. In this situation it is difficult, if not impossible, to achieve and maintain theraputic blood levels of vancomycin (either trough levels [5-12 mcg/mL] or peak levels [15-20 mcg/mL]). For these reasons, linezolid or daptomycin are preferred.
• Prior use of vancomycin will induce resistance to subsequent administration of daptomycin.
• Because of its once-weekly dosing regimen, dalbavancin should be considered in patients receiving prolonged antibiotic therapy for susceptible organisms, including all non-enterococcal streptococci, MSSA, MRSA, vancomycin-intermediate S aureus (VISA), CoNS, and vancomycin-sensitive enterococci. ^[12]
• If the joint does not show clinical improvement within 72h (or if cultures remain positive after 5d or inflammatory markers do not decline), surgical drainage should be strongly considered, the joint fluid should be reexamined for crystals, and other diagnoses should be considered (eg, Lyme or reactive arthritis).
• All sexual contacts of patients with gonococcal arthritis should be treated with a single dose of ceftriaxone 125 mg IM or of cefixime 400 mg PO.