Which of the following is an example of an adverse reaction rather than an allergic reaction to a medication?

Nausea and vomiting represent an adverse reaction to a medication, as they are common side effects that can occur as a response to a drug's pharmacological effects rather than an immune system response. Adverse reactions can include a wide range of responses that may not involve an allergic mechanism, and they often occur in a predictable manner based on how the drug affects the body.

In contrast, the other options involve symptoms that are characteristic of allergic reactions. Rash and hives, as well as swelling of the face and throat, indicate an immune response where the body recognizes the medication as a foreign substance, triggering histamine release and other mediators. Anaphylaxis, which includes trouble breathing, is a severe, potentially life-threatening allergic reaction and is distinctly different from straightforward adverse reactions like nausea or vomiting.

Understanding the difference between adverse reactions and allergic reactions is crucial in clinical practice to ensure appropriate management and treatment of patients experiencing these effects from medications.