Successful Management of Infective Endocarditis utilizing Rapid High-performance Liquid Chromatography-based Therapeutic Drug Monitoring: Balancing Linezolid Efficacy and Thrombocytopenia Risk.

Linezolid (LZD) is an effective alternative to vancomycin (VCM) for the treatment of methicillin-resistant Staphylococcus-associated infective endocarditis (IE), including cases involving prosthetic materials. However, the prolonged use often leads to thrombocytopenia, thus highlighting the importance of therapeutic drug monitoring (TDM) for dose optimization. We herein present the case of slowly progressive methicillin-resistant Staphylococcus epidermidis IE affecting a mitral annuloplasty ring in a 69-year-old afebrile patient whose only manifestation was a recurrent cerebral embolism. TDM-guided LZD dose adjustments using rapid high-performance liquid chromatography enabled the successful completion of a six-week antibiotic course while preventing severe thrombocytopenia and ensuring no further stroke recurrence.