A General Method of Optimizing Individual Drug Dosage

Abstract

For many drugs there is a high correlation between the concentration of drug in serum and clinical reponse. Optimal therapy with these drugs requires exceeding a minimal effective concentration (below which no adequate response is seen) while remaining below a maximal allowable concentration (above which drug toxicity becomes evident). Thus, a dose may be chosen quite rationally by the use of a desired serum concentration as the “therapeutic” end point. However, it is not possible to give the same dosage to all patients; a dose which proves effective in one patient will be ineffective in some and even toxic in others. This is because the dosage required to achieve serum concentrations within a certain, frequently narrow, range is confounded by variations in the way in which different individuals distribute and eliminate drugs.