Severe lactic acidosis associated with oral linezolid

We present the case of a patient with cystic fibrosis on long-term oral linezolid treatment for Mycobacteria abscessus lung infection who developed severe linezolid-induced lactic acidosis (LILA) resulting in deranged clotting and pancytopenia. The lactic acidosis was resistant to treatment with intravenous fluid but resolved within 20 hours of initiating continuous veno-venous haemofiltration. An unintended consequence of haemofiltration was that vascular access interfered with effective chest physiotherapy, resulting in worsened lung consolidation requiring prolonged intravenous antibiotic therapy for coexisting Pseudomonas aeruginosa infection. Given the potential mortality and morbidity of LILA, monitoring lactate levels may be clinically important but the optimum timing of monitoring is currently unclear.