Background Linezolid is widely used in the treatment of drug-resistant tuberculosis (TB), but it is associated with severe adverse effects, including lactic acidosis, which remains underreported in the literature and is fatal in many cases.

Methods This systematic review followed PRISMA guidelines and was registered in PROSPERO (CRD42024552225). We conducted comprehensive searches across PubMed, Scopus, Embase, and Google Scholar, covering case reports and case series without language restrictions. Data were extracted on demographics, clinical presentation, Linezolid dosage, laboratory findings, treatment regimens, and outcomes. Lactic acidosis was defined as a serum pH <7.25 and lactate >4 mmol/L. Quality assessment followed the protocol of Murad MH et al. Data were synthesized narratively and statistically analyzed using Microsoft Excel.

Results Seven case reports were identified. The average patient age was 49.33 years (range: 20–81 years), with a near-equal distribution between males and females. Most cases were reported from India (3/7). Respiratory symptoms predominated, with gastrointestinal and central nervous system involvement also noted. Linezolid dosing varied between 600 mg and 1200 mg daily. Arterial blood gas analysis showed significant acidosis, with pH values ranging from 6.09 to 7.32. Lactate levels were elevated (range: 10.2–20 mmol/L). Symptoms emerged within 7 days to over 1 month after starting Linezolid, except for one patient who developed symptoms immediately. Four patients died, and three survived after treatment modification.

Conclusion Linezolid-induced lactic acidosis is a rare but serious complication in drug-resistant TB, emphasizing the need for close monitoring and individualized treatment.

The authors have declared no competing interest.

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