Linezolid-induced pancytopenia and hyponatremia

Linezolid (LnZ) is an antibiotic that is effective against Gram-positive bacteria and vancomycin-resistant enterococcus. LnZ is notorious to cause adverse hematological effects, primarily thrombocytopenia; however, pancytopenia is an infrequent complication. Euvolemic hyponatremia is a very rare adverse effect in patients receiving LnZ for more than 2 weeks. Early identification of pancytopenia and hyponatremia due to LnZ can result in avoidance of unnecessary investigations with improved patient outcome. An 80-year-old male with no previous comorbidities was admitted with a fracture neck of the left femur. He was empirically prescribed tablet LnZ 600 mg twice daily by the orthopedics team for soft-tissue infection over the sacral area. He underwent surgery for the left femur's fracture neck and was continued on LnZ in the postoperative period. Two weeks after the surgery, he was noticed to have pancytopenia and hyponatremia. After a thorough evaluation, LnZ was suspected to be the cause of pancytopenia and euvolemic hyponatremia. After 2 weeks of withholding LnZ, his pancytopenia and hyponatremia resolved. Physicians should be aware of the rare adverse effects of LnZ and should identify the patients at risk before administrating the drug. Regular monitoring of hematological and biochemical parameters is mandatory if intended to continue the drug for a more extended period.