Increased Incidence of Blood Product Transfusions Among Transplant Patients Treated with Linezolid Compared to Daptomycin

Ashley Limkemann, Jeffery Tessier, Leahna Haldeman, Andrew Young, Teddy Puzio, Luke Wolfe, Jinfeng Han, Therese Duane, Virginia Commonwealth University

Background: Thrombocytopenia is a known complication of prolonged linezolid use although little data exist specifically in the transplant population who may be at higher risk secondary to ongoing immunosuppression. This study evaluates the hematological safety of linezolid for the treatment of infections in transplant recipients compared to transplant patients treated with a control antibiotic, daptomycin.

Hypothesis: The incidences of hematological toxicity are increased in transplant patients treated with linezolid compared to transplant patients treated with daptomycin.

Methods: We performed a retrospective study from 1/08 through 6/12 of transplant inpatients on immunosuppression treated with linezolid (LZD) or daptomycin (DAP) excluding patients: <18 years old, pre-engraftment after HSCT, relapsed cancer, aplastic anemia, or those who had received cytotoxic therapy or antibodies within 30 days preceding treatment. Outcomes included the incidences of anemia, leukopenia, or thrombocytopenia at the end of antimicrobial treatment, and blood product transfusions.

Results: The LZD cohort included 126 incidences, while the DAP cohort included 130 incidences of treatment. The demographic and baseline clinical variables were similar between cohorts. DAP cohort were more likely to be treated for blood stream infections (46.15% vs 31.75%; P=.02), while LZD group received more linezolid doses (15.8 vs 9.74; P<0.0001) than daptomycin doses received by the DAP group. LZD patients were more likely to receive red blood cell (68% vs 50.8%; P=0.007) and platelet transfusions (38.4% vs 20.8%; P=0.002) during course of treatment. For patients receiving thrombocytopenic drugs, mycophenolate and/or chemotherapeutic agents, end of treatment (EOT) platelet <150K was not statistically significant in the LZD cohort compared to DAP (54.8% vs 40%; P=0.09).

Conclusions: Transplant patients who received linezolid had a higher incidence of blood product transfusions, compared to transplant patients who received daptomycin. Although there was no statistically significant EOT thrombocytopenia between cohorts, LZD patients were more likely to receive platelet transfusion during the course of treatment. The difference may be related to greater drug exposure (number of doses) in the LZD cohort. Clinicians caring for transplant patients should account for the need for blood products when considering the use of linezolid.