Analyses of teicoplanin concentrations from 1994 to 2006 from a UK assay service
Journal of Antimicrobial Chemotherapy
Objectives: An analysis of the trough serum concentrations sent to the UK Antimicrobial Reference Laboratory for teicoplanin therapeutic drug monitoring (TDM). Methods: All trough concentrations over a 13 year period were analysed and the percentages were calculated for the following: ,10 mg/L (a sub-optimal concentration for all); ≥10-,20 mg/L (the target used for ordinary Gram-positive infections); ≥20 -,60 mg/L (the target for all severe staphylococcal infections including endocarditis); and
... endocarditis); and ≥60 mg/L (the concentration associated with toxicity). Results: The percentage of patients with concentrations of ,10 mg/L decreased each year to 13% in 2006. Almost 40% of the samples each year were in the ≥10 -,20 mg/L range. In 1996, the percentage of samples in the ≥20 -,60 mg/L range reached a study high of 70%. That percentage then fell to 30% and increased slowly to 50% at the end of the study. Fewer than 5% of the samples were ≥60 mg/L. Conclusions: Our study shows that there is a need to increase the initial dose or extend the number of days that the loading dose is used in a significant number of patients. With such a wide optimal range and a low potential for toxicity, it is unclear why optimal therapy is not achieved in a higher percentage of patients.