In noncompartmental analysis (NCA) of PK data, which metrics are typically used to summarize oral drug disposition?

• A. AUC and Tmax
• B. AUC and Cmax
• C. Cmax and Tmax
• D. Clearance and Volume of distribution

Answer: (B)

In noncompartmental analysis, the standard way to summarize oral drug disposition focuses on total exposure and the peak concentration. AUC measures the body's overall exposure to the drug over time, reflecting how much drug enters systemic circulation and how it is cleared. Cmax is the highest plasma concentration reached, indicating the peak level after absorption and distribution. Tmax, while it tells you when the peak occurs, is a timing parameter and doesn’t summarize disposition as directly. Therefore, AUC and Cmax together capture both the extent of exposure and the peak concentration after oral administration, making them the typical pair used in NCA. Choices that emphasize Tmax alone or rely on model-derived parameters like clearance and volume of distribution don’t provide the same robust summary for oral PK in noncompartmental analysis.