What distinguishes a medication allergy from medication intolerance?

The distinction between a medication allergy and medication intolerance is fundamentally rooted in the nature of the body's response to the medication. A medication allergy triggers an immune response—this means that the immune system mistakenly identifies a medication as harmful and reacts to it, potentially leading to severe symptoms such as hives, swelling, difficulty breathing, or anaphylactic shock.

In contrast, medication intolerance typically results in non-immune related side effects that can be bothersome but are usually less severe. For example, intolerance may manifest as mild digestive upset such as nausea or diarrhea, which does not involve the immune system.

Understanding this difference is vital for healthcare professionals, as managing allergic reactions often requires immediate intervention and avoidance of the offending medication, while intolerances might be managed by adjusting doses or switching to alternative therapies. Thus, option B accurately reflects the defining characteristic of a medication allergy.