Simplified dosing regimens of teicoplanin for patient groups stratified by renal function and weight using Monte Carlo simulation

The purpose of this study was (i) to determine the optimal dosage of teicoplanin for each patient group stratified by renal function and weight based on a population pharmacokinetic model and observed distribution of patient characteristics and (ii) to develop new simplified dosing regimens designed to achieve 15-30 μg/mL. Patient data were collected retrospectively from routine therapeutic drug monitoring files of adult patients who were given the standard loading dose regimen of teicoplanin (400 mg twice on Day 1, followed by 400 mg once daily for 2 days) and whose trough concentration was measured just before administration on Day 4. Monte Carlo simulation was conducted to estimate the trough concentration at 72 h after the initial loading dose (C_{min 72 h}) and at steady state (C_{ss min}). The percentage of observed C_{min 72 h} in patients who received the standard loading dose regimen outside the non-parametric 90% prediction interval (from 5th to 95th percentile) of the simulated C_{min 72 h} was <10%. Simplified loading dose and maintenance dose regimens for each group stratified by renal function and weight were created to achieve C_{min 72 h} and C_{ss min} of 15 μg/mL and 20-25 μg/mL, respectively. The percentage of C_{min 72 h} and C_{ss min} in the range 15-30 μg/mL was 43-65% and 61-82% across each renal function and weight strata, respectively. These new simplified dosing regimens of teicoplanin could be helpful in individual adjustment of the loading and maintenance doses to achieve 15-30 μg/mL.