# Predictors of target initial teicoplanin trough concentration attainment in patients with hematological malignancies: a retrospective cohort study

## TL;DR

This study identifies factors that predict whether patients with blood cancers achieve effective teicoplanin drug levels after initial treatment.

## Contribution

The study identifies specific clinical and treatment-related predictors of teicoplanin trough concentration attainment in hematological malignancy patients.

## Key findings

- 51% of patients achieved target teicoplanin trough concentrations after loading doses.
- Febrile neutropenia, bone marrow transplantation, tacrolimus coadministration, and cumulative teicoplanin dose are independent predictors of target attainment.
- Patients with multiple risk factors had a 22% attainment rate when receiving lower teicoplanin doses.

## Abstract

Teicoplanin (TEIC) is frequently used at Osaka Metropolitan University Hospital to treat infections caused by gram-positive cocci in patients with hematological malignancies. However, in certain cases, the initial trough concentrations failed to reach the target level, despite appropriate loading doses. Therefore, this study aimed to identify the factors associated with achieving target concentrations based on the initial trough level following TEIC loading in patients with hematological malignancies.

We retrospectively analyzed patients with hematological malignancies treated with TEIC between January 2016 and December 2022. Patients were classified into a target trough attainment group (trough ≥ 15 µg/mL) and a non-attainment group (trough < 15 µg/mL) according to the initial trough concentration measured on day 4 after administering the loading doses. Demographics, clinical laboratory data, TEIC dosing, and concomitant medications were compared between groups. Factors independently associated with the target trough concentration were assessed using multivariate logistic regression analysis.

Among the 176 patients, 90 (51%) achieved the target trough concentration, while 86 (49%) did not. Multivariate analysis identified febrile neutropenia, history of bone marrow transplantation within 30 days, presence or absence of tacrolimus (TAC) coadministration, and cumulative TEIC dose over the first 3 days as independent predictors of target attainment. The target concentration attainment rate was only 22% among patients with febrile neutropenia who received a TEIC cumulative loading dose of < 40 mg/kg over the first 3 days after initiation and did not receive TAC coadministration.

Achieving adequate TEIC concentrations early in therapy is critical for the successful treatment of immunocompromised patients with hematological malignancies. Our findings indicated that the likelihood of target trough concentration attainment markedly reduced in patients with multiple risk factors for subtherapeutic exposure. Accordingly, higher doses should be administered, particularly to patients with these factors.