Hypersensitivity is

Hypersensitivity is

• A. A non-immune adverse effect
• B. Allergic or other immunologic response to drugs resulting from previous sensitizing exposure
• C. A dose-dependent adverse effect
• D. A response due to drug interactions

Answer: (B)

Hypersensitivity is an immune-mediated adverse drug reaction that requires prior sensitization to the drug. After the initial exposure, the immune system becomes primed, and upon re-exposure it may mount an allergic or other immunologic response. This can range from mild rashes to severe reactions like anaphylaxis, and it includes both IgE-mediated and other immune pathways (including T-cell–mediated and immune complex–related processes). This differs from dose-dependent toxicity, which is a direct, non-immune effect that worsens with higher drug levels, and from adverse effects caused by drug interactions, which arise from interactions between multiple drugs rather than immune sensitization. So the best description is an allergic or immunologic response to a drug resulting from previous sensitizing exposure.

Hypersensitivity is an immune-mediated adverse drug reaction that requires prior sensitization to the drug. After the initial exposure, the immune system becomes primed, and upon re-exposure it may mount an allergic or other immunologic response. This can range from mild rashes to severe reactions like anaphylaxis, and it includes both IgE-mediated and other immune pathways (including T-cell–mediated and immune complex–related processes).

This differs from dose-dependent toxicity, which is a direct, non-immune effect that worsens with higher drug levels, and from adverse effects caused by drug interactions, which arise from interactions between multiple drugs rather than immune sensitization. So the best description is an allergic or immunologic response to a drug resulting from previous sensitizing exposure.