What is an allergic reaction to medication?

An allergic reaction to medication is characterized as the body's hypersensitive reaction to a medication. This occurs when the immune system mistakenly identifies a substance in the medication as harmful and triggers an immune response. This can lead to various symptoms, ranging from mild rashes or hives to more severe reactions like anaphylaxis. Recognizing an allergic reaction is crucial for proper patient management, as it may necessitate immediate medical attention and the discontinuation of the offending medication.

In contrast, a normal response to medication refers to the expected effects that medications have on the body based on their pharmacological properties, which do not involve an immune reaction. Expected side effects of treatment are common and can occur in many patients without indicating any hypersensitivity; they are anticipated outcomes based on the drug's action. A mild discomfort from medication also does not align with the definition of an allergic reaction, as it generally pertains to tolerable and non-immune-mediated responses, rather than a reaction driven by the immune system.