AUCivdoseiv

AUCivdoseiv refers to a term used in pharmacokinetics discussions to describe how drug exposure after an intravenous dose relates to the size of that dose. It is not a standard formal notation in the literature, but it is sometimes used in teaching materials and simulation models to illustrate the relationship between the area under the plasma concentration–time curve after IV administration and the administered IV dose.

In most IV pharmacokinetics, the area under the curve (AUC) for a given dose is AUC_iv = Dose_iv / CL, where CL is clearance. Therefore the ratio AUC_iv / Dose_iv is equal to 1/CL and is independent of the dose under linear kinetics. Consequently AUCivdoseiv is often interpreted as AUC per unit dose following IV administration, giving a measure with units of time per volume (e.g., h/L).

Use and limitations: The concept helps illustrate that, for a given clearance, doubling the IV dose doubles AUC, leaving AUC per unit dose unchanged. It is not typically reported in clinical studies; standard summaries use AUC0-∞ or AUC0-t, and clearance or bioavailability for cross-route comparisons.

Limitations: in nonlinear PK, saturable processes, time-varying clearance, or prodrugs, the ratio is no longer constant, and AUC is not proportional to dose.

Origin: the term is a concatenation of AUC, IV, dose, IV; used informally rather than as a formal parameter.

See also: area under the curve, pharmacokinetics, intravenous administration, clearance, dose, linear pharmacokinetics.