Certified Clinical Research Associate (CCRA) Practice Exam 2025 – Complete Preparation Guide

The assessment of tolerance towards a drug typically involves observing how the body's response to a substance changes over time with continued use. Single and multiple dose pharmacokinetic (PK) studies are particularly relevant in this context, as they involve measuring how the drug is absorbed, distributed, metabolized, and excreted in the body after administration of one or multiple doses.

In these studies, researchers can determine whether there is a change in the pharmacokinetic parameters after repeated dosing, which could indicate the development of tolerance. For instance, if a drug's concentration in the bloodstream does not correlate with its expected pharmacological effect after prolonged use, this could suggest that the body is becoming tolerant to the medication's effects.

In contrast, other types of studies mentioned, like comparative studies, mortality studies, and clinical safety studies, focus more on direct comparisons of efficacy or safety outcomes rather than specifically examining how repeated exposure to a drug affects tolerance. Thus, single and multiple dose pharmacokinetic studies are the most direct way to assess tolerance towards a drug.