Age- and gender-related differences in teicoplanin levels in paediatric patients.

OBJECTIVES: Teicoplanin is a glycopeptide antibiotic active against Gram-positive bacteria, including methicillin-resistant staphylococci. While teicoplanin trough levels (TTLs) >10 mg/L are commonly considered appropriate, levels >20 mg/L are aimed for in the treatment of severe infections. Due to toxicity, it is recommended to avoid levels >60 mg/L. PATIENTS AND METHODS: In our institution, the initial dosing schedule of teicoplanin (10-15 mg/kg every 12 h for three loading doses and every 24 h thereafter) is adapted according to TTLs analysed by a fluorescence polarization immunoassay on treatment days 2 to 4. Teicoplanin peak levels (TPLs) are analysed in selected cases 30 min after the end of infusion. In a retrospective analysis we evaluated 1357 TTLs and 333 TPLs from 410 treatment episodes from 2005 to 2011.
RESULTS: Initial TTLs were <10 mg/L in 14.1% and <20 mg/L in 72.6% of episodes. Toddlers had significantly lower TTLs, with a 2-fold and 2.5-fold increased risk of having levels <10 mg/L (24.6%) and <20 mg/L (82.6%), respectively. For the entire cohort, follow-up TTLs were less likely to be <10 mg/L and more likely to be >20 mg/L when compared with initial TTLs (P < 0.001, each). Adolescent girls had significantly higher initial TPLs (P = 0.001) and significantly higher follow-up TTLs (P = 0.016) than adolescent boys. In parallel, adolescent girls had initial TPLs >60 mg/L significantly more frequently (P = 0.012) and follow-up TTLs <10 mg/L significantly less frequently (P = 0.005).
CONCLUSIONS: More tailored dosing regimens with higher loading doses, especially for toddlers, should be considered. While further pharmacokinetic data in paediatric patients are pending, therapeutic drug monitoring is mandatory.