Background and Importance The pharmacokinetics of vancomycin vary significantly between specific groups of patients, such as patients with haematological malignancy with febrile neutropenia. Recent evidence suggests that the use of the usual standard dose of antibiotics in patients with febrile neutropenia may not offer adequate exposure due to pharmacokinetic variability.

Aim and Objectives To assess the effect of febrile neutropenia on the AUC0–24 hours as a key parameter for vancomycin monitoring, as well as to determine which vancomycin pharmacokinetics parameters are affected by the presence of febrile neutropenia using Bayesian software PrecisePK in haematological malignancy with febrile neutropenia.

To evaluate the difference in estimated AUC0–24 between febrile neutropenia and non-febrile neutropenia among patients with haematological malignancies.

Material and Methods The study included adult patients admitted between January 2017 and December 2020, who received vancomycin with measured steady-state trough concentrations before the fourth dose. Of the 297 patients treated, 217 met the inclusion criteria. Pharmacokinetic parameters for both neutropenic and non-neutropenic patients were estimated using the precise PK Bayesian platform.

Results The result showed that AUC0–24 was lower in febrile neutropenic patients p < 0.05 (403 vs. 461 mg·h/L) compared to non-febrile neutropenia patients. Also, there was a significant difference (p < 0.05) in vancomycin clearance, the volume of distribution at a steady state, the volume of distribution for the peripheral compartment, the half-life for the elimination phase, and the first-order rate constant for the elimination process in febrile neutropenia group compared to non-febrile neutropenic patients.

Conclusion and Relevance Febrile neutropenia has a significant effect on the pharmacokinetics parameters of vancomycin and AUC0–24, which may require specific consideration during the treatment initiation.

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Conflict of Interest No conflict of interest.