Which of the following is not one of the major uses of medications?

The major uses of medications encompass a variety of therapeutic objectives aimed at improving patient health. Symptom relief pertains to the use of drugs to alleviate the signs and symptoms of diseases, enhancing the quality of life for patients. Preventive medications are employed to avert the onset of diseases or complications, playing a crucial role in public health by reducing the incidence of conditions such as infections or chronic diseases. Diagnostic medications are used to aid in the identification of diseases by eliciting specific responses in the body that can provide insight into a patient's condition.

Adverse reactions, while critical to recognize in the context of medications, do not constitute a major use. Instead, they refer to unintended and often harmful side effects that can occur as a result of medication use. Understanding adverse reactions is essential for healthcare providers to ensure patient safety, but they are not an intended use of medications—rather, they are considerations that need to be managed during treatment. Hence, recognizing that adverse reactions do not serve a beneficial purpose aligns with identifying them as not one of the major uses of medications.