A comparative evaluation of adverse platelet outcomes among Veterans' Affairs patients receiving linezolid or vancomycin.
J Antimicrob Chemother. 2012 Mar;67(3):727-35
Authors: Patel N, VanDeWall H, Tristani L, Rivera A, Woo B, Dihmess A, Li HK, Smith R, Lodise TP
OBJECTIVES: The primary objectives were to compare the incidences of severe thrombocytopenia, critical thrombocytopenia and a relative decline in platelets from baseline (?50% decline) between patients receiving linezolid and those receiving vancomycin. The secondary objective was to assess the relationship between vancomycin trough concentration and adverse platelet outcomes.
METHODS: A matched cohort study was performed at the Upstate New York Veterans' Affairs Healthcare Network from January 2005 until February 2008. Eligibility criteria were: (i) receipt of linezolid or vancomycin therapy for ?48 h; (ii) initiation of therapy as an inpatient; and (iii) baseline platelets available for evaluation. Patients who received linezolid were matched 1:1 to patients who received vancomycin. Cumulative incidences and times to event for (i) platelet count ?50,000 cells/mm(3), (ii) platelet count ?20,000 cells/mm(3) and (iii) ?50% decline in platelets from baseline were evaluated. Multivariate analyses were performed.
RESULTS: The study included 502 patients (251 matched pairs). The occurrences of platelet counts ?50,000 cells/mm(3) and ?20,000 cells/mm(3) did not differ significantly between linezolid and vancomycin patients. A ?50% decline in platelets from baseline was observed in 78 (31.1%) patients receiving vancomycin and 43 (17.1%) patients receiving linezolid (risk ratio 0.55; 95% CI 0.40-0.77). A clear exposure-response relationship was observed between vancomycin trough concentration and ?50% decline in platelets from baseline.
CONCLUSIONS: The incidence of thrombocytopenia was low and did not differ significantly among vancomycin and linezolid patients.
PMID: 22174041 [PubMed - indexed for MEDLINE]