Mitochondrial Toxicity Associated with Linezolid

To the Editor: Linezolid belongs to a family of antimicrobial agents (oxazolidinones) that inhibit bacterial protein synthesis by preventing the fusion of 30S and 50S ribosomal subunits.1 Hyperlactatemia, metabolic acidosis, and peripheral neuropathy are adverse effects of linezolid,2,3 which could be related to the drug's capacity for interference with mitochondrial function.4 We studied mitochondria from three patients in whom asthenia and hyperlactatemia developed during a prolonged course of oral linezolid (600 mg every 12 hours). Patient 1, a 25-year-old man with Enterococcus faecium infection of a knee prosthesis, received oral linezolid. After three months, mild asthenia and hyperlactatemia developed . . .