Examination of the Relationship Between Antimicrobials and Thrombocytosis

OBJECTIVE: To evaluate whether there is a relationship between antimicrobial therapy and the development of thrombocytosis. DATA SOURCES: Literature was accessed through EMBASE (1977-June 2012) and MEDLINE (1977-June 2012) using the terms thrombocytosis and antimicrobial. In addition, reference citations from publications identified were reviewed. STUDY SELECTION AND DATA EXTRACTION: All English-language publications identified were evaluated. For case reports, the Naranjo probability scale was used to calculate the likelihood of the drug causing the reaction. DATA SYNTHESIS: Thrombocytosis occurring during antimicrobial therapy is well documented, with several case reports and clinical trial observations. However, a direct causal relationship is not yet supported by the available literature. Platelets are well known to be an acute phase reactant, with an elevated count occurring after acute conditions such as blood loss, inflammation, or infection. Thrombocytosis during antimicrobial therapy may be the result of an infectious process and not an adverse drug event. CONCLUSIONS: Based on the current available literature, a definitive link cannot be established between antimicrobial therapy and occurrence of thrombocytosis.