Linezolid-Induced anemia and thrombocytopenia

Linezolid, a fluorinated oxazolidinone, is the first of a new class of antimicrobials designed to target resistant gram-positive cocci. Hematologic adverse effects, including reversible thrombocytopenia, were reported during phase III comparator-controlled trials. A 66-year-old man developed sternal osteomyelitis due to methicillin-resistant Staphylococcus aureus after undergoing coronary artery bypass graft surgery. Methicillin-resistant S. aureus bacteremia developed after several surgical debridements and courses of vancomycin failed to improve the patient's condition. Oral linezolid 600 mg twice/day was begun; 17 days later, a complete blood count revealed that his hematocrit had decreased from 37.4% to 24.8%, and his platelet count had decreased from 234 x 10(3)/mm3 to 149 x 10(3)/mm3. Both values returned to normal after linezolid was discontinued. Complete blood counts should be monitored closely in patients taking linezolid, especially if therapy continues for more than 14 days.