Thrombocytopenia Associated with Teicoplanin Use: A Retrospective Observational Study.

Background: Contradictory studies reporting vast heterogeneity in the teicoplanin-induced thrombocytopenia (TIT) incidence exist. Objective: To identify the incidence of TIT associated with teicoplanin dosing range (6–12 mg/kg/dose) and the risk factors of TIT. Methods: This retrospective observational study included adult patients who received teicoplanin for ≥3 consecutive days over a period of 3.5 years. Thrombocytopenia was defined as a platelet count of <100 × 103/µL coupled with at least a 25% drop from the baseline count. The TIT incidence was assessed using the adverse drug reaction probability scale (Naranjo scale). Results: Data from 482 patients who received teicoplanin and met the predefined inclusion criteria were included in the analyses. The cohort presented a mean age of 53.5 ± 19 years, where 72.4% were male, and 49.2% exhibited normal baseline renal function. Teicoplanin was most commonly used for bacteremia (n = 134), and the most common isolated pathogen being Staphylococcus aureus (n = 221). The TIT incidence was 4.6% (the possible and probable category using the Naranjo scale; 22/482). The median time to first platelet count dropped to <100 × 103/µL after teicoplanin initiation was 5 (interquartile range [IQR], 3-10) days and 8 (IQR, 5-14) days till the maximum platelet count dropped. None of the tested patient variables were found to be independently associated with an increased risk of thrombocytopenia. Conclusion and Relevance: The overall TIT incidence was low across our study cohort, including critically ill patients. Our study results may aid in the optimal monitoring of such serious teicoplanin-induced adverse effects.