Determination of pharmacokinetic constants after multiple infusions of drugs.

Techniques for determining pharmacokinetic constants after single doses of drugs, or after different doses at fixed intervals or fixed doses at different intervals have been published previously. A generalised algorithm for determining pharmacokinetic constants has been developed for use where irregular intravenous doses given by bolus and/or infusion and irregular dosing intervals are used. The algorithm is robust and, based on data from simulation studies, will give good estimates of pharmacokinetic constants even with irregularly space data having up to 30% random error or as few as 1 degree of freedom. The use of the algorithm provides a way of obtaining pharmacokinetic constants from situations which may have been regarded previously as "too complex".