Tongue discoloration in an elderly kidney transplant recipient: Treatment-related adverse event?

Background: With the increased occurrence of methicillin-resistant staphylococcus aureus infections, linezolid treatment might be administered more often. New rare adverse events are likely to follow.

Case Summary: A 65-year-old man (weight, 91 kg; height, 185 cm) presented to the emergency department at the University of Virginia-affiliated Salem Veterans Affairs Medical Center, Salem, Virginia, after a recent (8 weeks) kidney transplantation with a 24-hour history of fatigue, chills, arthralgias, increased urinary frequency, and onset of tongue discoloration. Two days before admission, he completed a 14-day course of linezolid 600 mg PO BID for ampicillin-resistant enterococcal urinary tract infection. He was afebrile on admission and the dorsal aspect of his tongue was blackened centrally, browner peripherally, with normal pink mucosa on the periphery. Based on the Naranjo probability scale, the calculated score for tongue discoloration as a drug-related adverse event was 7 out of a maximum score of 13 points, designating it as a probable cause. The patient's tongue discoloration improved moderately during the hospital stay and resolved 6 months after the discontinuation of linezolid.

Conclusions: We report a rare association of linezolid and tongue discoloration in an elderly kidney transplant recipient that improved with discontinuation. We present this case to increase clinicians' awareness of the potential adverse event.