What are all adverse reactions classified as?

Adverse reactions are classified as undesirable effects because they represent negative responses to a medication or treatment that are not the intended therapeutic outcomes. These reactions can range in severity and can occur in any patient, regardless of how carefully a medicine is administered. Understanding that adverse reactions are categorized as undesirable underscores the importance of monitoring patients and minimizing risks associated with pharmacological interventions.

Desirable effects would refer to the benefits or positive responses from a medication, while side effects, although similar to adverse reactions, can sometimes be considered expected outcomes that are typically minor or tolerable compared to the core therapeutic effect. Toxic reactions refer specifically to severe adverse effects resulting from excessive dosing or hypersensitivity, rather than the broader category of all adverse reactions. Therefore, classifying all adverse reactions as undesirable effects captures their inherent negative implications in the context of pharmacology.