[Estimation of pharmacokinetic constants in irregular repeated drug administration (author's transl)]

Least squares estimations for the fraction of the dose absorbed, volume of distribution, absorption and elimination rate based on drug measurements in blood and urine after aperiodical administration are described for a one-compartment model with first-order absorption. The non-linear regression analysis is carried out by means of a modified Gauss-Newton iteration procedure by Hartley. BASIC and FORTRAN functions are developed and applied in an example. The advantages of unbiased and consistent least-squares estimations in pharmacokinetics are pointed out.