Phenytoin pharmacokinetic analysis and steady-state level prediction using a programmable calculator

This paper describes the use of a programmable calculator (HP-97) to determine the individualized Michaelis-Menten parameters of phenytoin by utilising the linear regression technique in fitting data of multiple doses and corresponding steady-state concentrations to a linear-transformed Michaelis-Menten equation and solving for the Michaelis-Menten parameters. In addition, the calculator program can predict the corresponding steady-state concentration of phenytoin for any given dose used in an individual by employing the derived Michaelis-Menten parameters and the Michaelis-Menten equation.