Effect of body composition on initial teicoplanin dosing and optimization of the regimen

Teicoplanin dosing in obese or underweight patients is uncertain due to its unique pharmacokinetic variability, potentially resulting in suboptimal exposure. This study seeks to establish a dosing strategy tailored to body composition by assessing the initial teicoplanin dosing regimen using different weight indices alongside actual body weight (ABW).

This retrospective study involved adult patients who were administered intravenous teicoplanin at Kumamoto University Hospital between 2017 and 2023. The ratio of initial trough concentration (μg/mL, C) to the total teicoplanin loading dose administered within 24 h (mg/kg/24 h, D) was evaluated based on body composition.

A total of 160 patients were included in the analysis. The mean C/D ratios were 0.42 ± 0.13, 0.52 ± 0.14, and 0.66 ± 0.14 in patients classified as underweight (BMI: <18.5 kg/m², n = 32), normal weight (BMI: 18.5 to <25 kg/m², n = 88), and obese (BMI: ≥25 kg/m², n = 40), respectively (P < 0.001, Tukey's honestly significant difference test). Bayesian-predicted pharmacokinetic parameters indicated that the smallest prediction errors were observed when ABW was used for underweight and normal-weight patients (43.8 ± 5.5 kg and 56.0 ± 7.2 kg, respectively). In contrast, standard body weight (SBW) and ideal body weight (IBW) yielded the lowest errors in obese patients.

Teicoplanin loading doses should be increased by ∼20% in underweight patients and decreased by ∼20% in obese patients compared to those in normal-weight patients. SBW- or IBW-based dosing is recommended in obese patients to prevent overexposure.