Safety and efficacy of linezolid in 16 infants and children in Japan

Linezolid, an oxazolidinone antibiotic, exhibits a broad spectrum of activity against Gram-positive bacteria. It hasbeen licensed for adult use in Japan since 2006 for MRSA infections, and has also been used off-label for pediatric patients.At our university hospital, a total of 16 infants and children (including one non-Japanese Asian) were administered linezolidowing to infection with multidrug-resistant Gram-positive bacteria, after consent had been provided. All patients had severeunderlying diseases or indications for surgery. Eighty-eight percent of the causal microorganisms were methicillin-resistantStaphylococcus aureus (MRSA) or methicillin-resistant coagulase-negative Staphylococcus and all were sensitive to linezolid.Linezolid was administered because the antecedent anti-MRSA medications were ineffective or contraindicated, orintravenous-to-oral switch therapy was requested owing to cardiac or orthopedic surgical-site infections. The median durationof administration was 13 days (range 3-31 days). The overall efficacy was 91 % (10/11) in those for whom efficacy could beevaluated. Only two patients (both teen-aged) encountered linezolid-related adverse effects (13 %, 2/16). One patient showedelevation of liver enzymes (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]), requiring thatadministration be withdrawn, but enzyme levels returned to normal after the patient had been switched to vancomycin. Theother patient showed transiently decreased platelet counts. Linezolid is considered generally safe and effective for childrenin Japan, especially for those who cannot use other anti-MRSA medications or those who require oral antibiotics forinfections with multidrug-resistant Gram-positive bacteria.