Recently, the design of individualized dosage regimens has been focused on the method based on the Bayesian principle. This method is available for estimating the individual pharmacokinetic parameters using only one or two plasma drug concentrations theoretically, but needs correct population prameter in order to obtain a good estimate of the individual parameters.
In this report, we evaluated accuracy of the Bayesian method for estimating the asthmatic children's pharmacokinetic parameters treated by theophylline slow-release preparation at Round The Clock (RTC) therapy. When the plasma drug concentration obtained 4 hours (Cl) after oral administration was used, considerable variation on estimative ability of Bayesian method was expected. This result suggested that Bayesian method was required optimal collection time of the blood sample. But, it was assumed that given the certain degree variance on calculation in consideration of difference of the preparations was possible to obtain a good estimate of the individual parameters.