Association of Clinical Research Professionals (ACRP) Certified Professional Practice Exam 2026 - Free ACRP Practice Questions and Study Guide

An Adverse Drug Reaction (ADR) can be defined as a noxious and unintended response to an investigational drug. This definition emphasizes two critical aspects: that the response is both harmful (noxious) and unintentional, meaning it occurs without the anticipation of the effects that could arise from the drug’s use.

Understanding that ADRs are adverse outcomes is crucial in clinical research and pharmacovigilance. These reactions can vary in severity and can impact patient safety and overall treatment outcomes. The focus on "unintended" highlights that the effects are not part of the drug's intended therapeutic effects, which differentiates ADRs from expected effects or beneficial outcomes.

Other options, while related to drug responses, do not accurately capture the definition of ADRs. For example, a mild response does not encompass the range of adverse effects that can occur, and a change in a subject's health status could be due to many factors beyond drug interactions. Furthermore, defining an ADR as a beneficial effect contradicts the very notion of it being adverse.