[The area between the x-axis and the curve given by the integrand. It is equal to the definite integral of a function. In the field of pharmacokinetics, the area under the curve (AUC) is the area under the curve in a plot of concentration of a drug in plasma against time. AUC is usually given for the time interval zero to infinity, and other time intervals are indicated. ( NCI )] (UMLS (NCI) C0376690) =Quantitative Concept