Pharmacy PEBC Practice Exam

What does the term "adverse drug reaction" (ADR) refer to?

1. An unintended harmful reaction to a medication at normal doses

2. A beneficial effect of a medication beyond its intended use

3. A reaction that occurs only when a medication is misused

4. An expected side effect of a medication

The correct answer is: An unintended harmful reaction to a medication at normal doses

The term "adverse drug reaction" (ADR) specifically refers to an unintended, harmful effect that occurs when a medication is taken at normal, therapeutic doses. This means that even when a drug is used as prescribed, it can still cause negative effects in certain individuals. An ADR can manifest in various ways, including allergic reactions, side effects, or any negative consequences that are not beneficial to the patient’s health. In the context of the other options, beneficial effects beyond intended uses do not classify as ADRs; instead, they may be referred to as off-label benefits. Furthermore, reactions that happen only with misuse of medication do not qualify as ADRs, since they are not a result of normal dosing. Lastly, expected side effects, while they may occur in conjunction with the use of a medication, are typically identified during the drug’s development and are not classified as adverse reactions; they are considered predictable outcomes that do not fall under the 'adverse' category. Therefore, defining ADRs strictly in terms of unintended harmful reactions at standard doses is crucial for accurate communication in clinical settings.