Clinical improvement of methicillin-resistant Staphylococcus epidermidis prosthetic knee joint infection after changing therapy from tedizolid to linezolid: A case report.

Periprosthetic joint infection (PJI) is a serious and challenging complication of total joint arthroplasty. Methicillin-resistant staphylococci are among the most common causative pathogens of PJI. Consequently, anti-methicillin-resistant Staphylococcus aureus agents are often required. Linezolid (LZD), an oxazolidinone antibiotic, is a therapeutic option because of its favorable bone penetration, although its long-term use is limited by hematological toxicity. Tedizolid (TZD), a second-generation oxazolidinone, has a more favorable hematological safety profile than LZD. Nevertheless, evidence comparing the efficacy of TZD and LZD in PJI remains scarce. We report a case of Methicillin-resistant Staphylococcus epidermidis (MRES) prosthetic knee joint infection (PKJI) in which infection worsened despite revision surgery, debridement, and prolonged TZD therapy; however, clinical improvement was achieved after switching to oral LZD. To minimize hematological toxicity during prolonged LZD therapy, the dose was reduced from 1200 to 600 mg/day while maintaining plasma trough concentrations of 1.113-5.065 μg/mL (target, 2-8 μg/mL) and an area under the concentration-time curve to minimum inhibitory concentration ratio of 108.3-257.6 (target, >100). The patient achieved sustained clinical improvement without severe thrombocytopenia. This case suggests that switching from TZD to LZD may be an effective therapeutic strategy when TZD fails to control MRSE PKJI and that therapeutic drug monitoring-guided dose adjustment may facilitate prolonged LZD therapy while minimizing hematological toxicity.