What does hypersensitivity refer to?

Hypersensitivity specifically refers to an unusual or exaggerated sensitivity to a drug or other substance. This may manifest as an adverse reaction that is more severe than what is typically expected from the pharmacological effects of the medication. For example, an individual with a hypersensitivity might experience severe allergic reactions, such as anaphylaxis, after taking a medication that would be well-tolerated by most other individuals.

In this context, options related to desensitization or normal reactions do not align with the definition of hypersensitivity, as they imply a reduced sensitivity or an expected response. Additionally, resistance to medication effects suggests a lack of response rather than an exaggerated one, which is also distinct from the concept of hypersensitivity. Therefore, unusual sensitivity is the most fitting description of what hypersensitivity entails.