Septic Arthritis of Native Joints Organism-Specific Therapy 

Updated: Oct 14, 2021
  • Author: John L Brusch, MD, FACP; Chief Editor: Michael Stuart Bronze, MD  more...
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Specific Organisms and Therapeutic Regimens

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]

Specific antibiotic therapy should not be switched from the IV to PO route until there is adequate documentation that the infection is responding appropriately

A recent study of SA of both native and prosthetic joints found that orally administered antibiotics started within 7 days of instituting IV therapy were noninferior to antibiotics administered intravenously through the entire therapeutic course (13% and 15%, respectively). The primary pathogens included S aureus (38%), coagulase-negative staphylococci (27%), and Streptococcus species (15%). Sixty-one percent had prosthetic-related infections. Rifampin was given to 41% of the IV group and 56% of the PO group. For initial oral treatment, the pathogen must be sensitive to antibiotics that have superior GI absorption, and the patient should have no major suppurative complications that would require surgery. These results need to be confirmed by follow-up studies. At minimum, this study may be useful in justifying switchover to PO antibiotics earlier than has been done in the past.  [11, 12]

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 is truly allergic to penicillin)*

Methicillin-resistant S aureus (MRSA)

Medications given for MRSA include the following:

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:

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

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

Gram-negative rods (other than Pseudomonas)

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

Pseudomonas aeruginosa

Medications given for Pseudomonas aeruginosa include the following:

Neisseria gonorrhoeae

Medications given for Neisseria gonorrhoeae include the following:

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 acheive and maintain either theraputic blood levels of vancomycin (either trough levels (5-12 mcg/mL) or peak levels (15-20 mcg/mL) . Consideration should then be given to the use of linezolid or daptomycin.
  • 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. [13]
  • If the joint does not show clinical improvement within 72h (or if cultures remain positive after 5d), surgical drainage should be 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.