Area Under the Plasma Concentration–Time Curve (AUC)

Definite integral of drug concentration in blood plasma over time, quantifying total systemic exposure after a single dose or dosing interval.

Specifications & Metrics

type: Pharmacokinetic Exposure Metric
symbol: AUC0–t / AUC0–∞ / AUC0–τ
units: mg·h/L, μg·h/mL, or ng·h/mL (or mol·h/L)
equation: AUC0–∞ = ∫₀^∞ C(t) dt = (F · Dose) / CL (estimated numerically by the linear/log trapezoidal rule)
pioneer: Non-compartmental pharmacokinetic analysis and LC-MS/MS bioanalysis

Measured by assaying serial blood plasma samples via LC-MS/MS and summing time intervals with the linear-up/log-down trapezoidal rule, AUC0–∞ represents the total integrated systemic exposure to a drug over time.
Because AUC0–∞ equals (F · Dose) / CL for any linear pharmacokinetic system, comparing oral and intravenous AUCs directly yields absolute bioavailability (F), while comparing AUCs in the presence and absence of a perpetrator drug quantifies CYP450 drug–drug interaction magnitude.
In toxicokinetics and antimicrobial PK/PD (such as AUC/MIC ratios for fluoroquinolones and vancomycin), AUC bridges preclinical animal NOAEL exposures to safe human starting doses.