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Rifampicin Timing in PJI DAIR — SCE Infectious Diseases MCQ

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ModerateBone & Joint InfectionRifampicin Timing in PJI DAIRSCE Infectious Diseases

A 50-year-old man develops late prosthetic knee joint infection (onset 14 months after primary TKR). Deep tissue cultures grow Staphylococcus epidermidis (methicillin-resistant, Rifampicin-susceptible). DAIR is performed. When should Rifampicin be added to the regimen?

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Correct answer: A — After blood cultures and wound cultures are sterile (typically 3–5 days) — Rifampicin should NOT be started while there is active bacteraemia or high bacterial burden due to rapid resistance development

Rifampicin is the cornerstone of anti-biofilm therapy for staphylococcal PJI with retained prostheses (DAIR). However, it must NEVER be used as monotherapy or started during active bacteraemia — resistance develops rapidly (within days) against high bacterial loads. The correct timing: start Rifampicin 2–5 days after surgical debridement, once wound cultures are sterile and any bacteraemia has cleared. Rifampicin is then continued for the entire antibiotic course (typically 3–6 months for knee PJI). Rifampicin is always used with a companion drug (Fluoroquinolone, Fusidic Acid, or Co-trimoxazole).

Reference: BSAC 2023 – PJI; ESC 2023 – Biofilm infections; NICE NG157