An algorithm for drug waste reduction using pharmacokinetic principles

When delivering several intravenous drug doses from a single bag, it is generally necessary to throw away any drug that remains in the bag, if the amount is insufficient to deliver the next dose. An algorithm has been developed to allow all of the drug in a bag to be used. Based on standard pharmacokinetic equations, the algorithm calculates the time when the remainder should be given, so that a desired peak serum drug concentration is achieved on the next dose. The algorithm requires as inputs the time limit on the bag, the dosing interval and the size of the dose. This algorithm applies only to drugs that obey single compartment, first-order linear kinetics (e.g. aminoglycosides), but is easily modified for other situations. In conjunction with computer-assisted infusion, use of the algorithm may potentially reduce the cost of aminoglycoside administration by reducing clinical drug waste.