Estimation of noncompartmental parameters: a technical note.

Noncompartmental pharmacokinetic parameters are usually expressed in terms of the area under the so-called first moment curve and the area under the plasma concentration-time curve. These areas are normally computed by numerical integration. There is an inconsistency in the way in which they are presently estimated. This inconsistency is detailed and a consistent approach to the computation of noncompartmental parameters is outlined. The difference between the two methods is illustrated using some data from the literature.