What does the term “adverse drug reaction” mean?

The term "adverse drug reaction" refers specifically to an unintended, harmful response that occurs when a medication is administered at normal doses during medical treatment. This definition emphasizes that the reaction is not only unintentional but also detrimental to the patient's health. Adverse drug reactions can manifest in various ways, including physical symptoms or changes in health status, and they underscore the importance of monitoring patients for negative effects from medications, even when used appropriately.

In contrast, the other choices describe different concepts related to medications. A beneficial effect of a drug highlights the therapeutic benefits a medication can provide, which is not aligned with the concept of an adverse reaction. A formal review of a drug's effectiveness pertains to pharmacological evaluations and does not address the negative outcomes that may arise from drug use. Lastly, a side effect that occurs only in rare cases does not capture the broader definition of an adverse drug reaction, which can happen at normal doses and is not limited to infrequent occurrences. Understanding the precise definition of adverse drug reactions is crucial for healthcare providers to ensure patient safety and appropriate management of pharmacotherapy.