Development of a limited sampling approach in pharmacokinetic studies: experience with the antiepilepsy drug...

A sparse sampling method is proposed to assess pharmacokinetic parameters after a single dose of the antiepilepsy drug tiagabine. Pharmacokinetic parameters obtained from two different pharmacokinetic studies were compared using sparse sampling (7 blood samples) with extensive sampling (15 to 16 blood samples). The results indicated that sparse blood samples taken at appropriate times can be used to estimate pharmacokinetic parameters as accurately as extensive blood samples. In addition, a limited sampling model (LSM) was developed using samples from 10 subjects at two time points (6 and 8 hours). The model was validated in 40 subjects and provided good population mean estimates of area under the concentration-time curve (AUC) and maximum concentration (Cmax). The sparse sampling method described here can be used to assess pharmacokinetic parameters in drug development provided a prior knowledge of the pharmacokinetics of a drug has been obtained from extensive sampling. Further, the LSM described here may be useful in estimating AUC and Cmax of tiagabine using two samples in clinical settings. The LSM approach described here can also be used to estimate AUC and Cmax of a drug in preclinical toxicokinetic studies without detailed pharmacokinetic studies.