Relevance of pharmacokinetic parameters in animal models of methamphetamine abuse

Although the behavioral consequences of methamphetamine (METH) abuse have been extensively documented, a more precise and thorough understanding of underlying neurobiological mechanisms still requires the use of animal models. To study these biochemical processes in experimental animals requires consideration for the broad range of human METH abuse patterns and the many factors that have been identified to profoundly influence the behavioral and neurochemical effects of exposure to METH-like stimulants. One potentially critical issue relates to pharmacokinetic differences between the species. In this review, METH plasma pharmacokinetic profiles after single and multiple dose intravenous METH administration are compared for the rat and human. Significant differences in elimination half-life between the two species (t1/2: rat-70 min, human-12 h) result in markedly dissimilar profiles of METH exposure. However, the plasma profile of a human METH binge pattern can be approximated in the rat by increasing METH dose frequency. Consideration of METH pharmacokinetics in animal models should permit a closer simulation of the temporal profile of METH exposure in the human CNS and should provide further insight into the mechanisms contributing to the addiciton and psychopathology associated with METH abuse.