“Standard” Is More Than Enough: Therapeutic Drug Monitoring Confirms Early Target Attainment of Teicoplanin Regimens in Pediatric Patients

Background: Therapeutic drug monitoring (TDM) is recommended for optimizing teicoplanin therapy, given its high pharmacokinetic variability. Recent literature suggests that standard dosing regimens are often insufficient to achieve therapeutic targets in pediatric patients. We aimed to evaluate real-world teicoplanin exposure, target attainment, and safety in a cohort of hospitalized children treated with standard dosing, incorporating an estimation of the unbound (free) pharmacologically active fraction. Methods: We conducted a retrospective cohort study at a tertiary pediatric care center (March 2018‒September 2022). Patients received standard dosing (loading dose 10 mg/kg q12h × 3, followed by maintenance). Trough concentrations (C trough ) were measured postloading dose (day 3). The cohort was stratified by age (0‒2 versus older than 2 years). Unbound teicoplanin concentrations ( f C trough ) were estimated using the Yano prediction model based on albumin levels. Results: A total of 63 TDM episodes from 52 patients were analyzed. The median total C trough was 57 mg/L (IQR 38‒84), significantly exceeding conventional therapeutic targets (10‒30 mg/L). Target attainment (C trough minimum threshold >10 mg/L) was achieved in 96.8% of cases. Patients aged 0–2 years exhibited significantly higher total concentrations compared with older children (median 69 versus 41 mg/L; P = 0.003) and higher estimated free concentrations (median 8.89 versus 5.77 mg/L; P = 0.008). Despite 47.6% of samples exceeding the reported toxicity threshold of 60 mg/L, no nephrotoxicity or adverse events were observed. No significant correlation was found between C trough and estimated glomerular filtration rate, whereas a positive correlation with albumin was confirmed. Conclusions: In this pediatric cohort, standard teicoplanin dosing resulted in early and high target attainment, challenging the notion that current regimens are widely subtherapeutic. The observed high total concentrations were well-tolerated, likely because the estimated free fraction remained within a safe range due to preserved albumin levels. Our findings support the safety and efficacy of standard dosing but highlight significant age-related pharmacokinetic variability, reinforcing the need for TDM protocols that integrate albumin monitoring to guide precision dosing.