Systemic exposure

Systemic exposure is a fundamental pharmacokinetic concept that describes the total amount of an active drug substance that reaches the systemic circulation and is available to exert its pharmacological effect (FDA, 2022). It is most commonly quantified using parameters such as the area under the plasma concentration-time curve (AUC) and the maximum plasma concentration (Cmax) (StatPearls, 2023). Unlike a specific biological target such as a receptor, enzyme, or ion channel, systemic exposure is a measure of the drug's presence and duration in the body over time (NIH, 2021). This exposure is determined by the complex interplay of absorption, distribution, metabolism, and excretion (ADME) processes (Wikipedia, 2024). Understanding systemic exposure is critical for establishing the relationship between the dose administered and the resulting clinical response, ensuring both therapeutic efficacy and safety. In drug development, monitoring systemic exposure helps identify the therapeutic window and manage risks associated with toxicity or therapeutic failure (PubMed, 2020).

Other names

Area under the curveAUCBioavailabilityDrug exposurePlasma concentration-time profile

Not applicable as systemic exposure is a pharmacokinetic parameter, not a molecular target.