Rare side effects of linezolid treatment on the tongue

Linezolid is a widely utilized antibiotic due to its efficacy against difficult-to-treat Gram-positive bacterial infections, including methicillin-resistant Staphylococcus aureus (MRSA) and glycopeptide-resistant enterococci. However, rare but reversible adverse effects such as black discoloration and fissured appearance of the tongue have been reported during linezolid therapy. In this study, we present four cases exhibiting black tongue discoloration and fissured tongue associated with linezolid use. These oral manifestations resolved shortly after discontinuation of linezolid and implementation of appropriate oral hygiene measures. Given the limited number of case reports in the literature, these findings underscore the importance of increasing clinician awareness regarding potential adverse effects of linezolid and facilitating early recognition of similar clinical presentations. In conclusion, identification and proper management of structural and pigmentary changes in the tongue during linezolid treatment are crucial for ensuring patient safety.