What term refers to a severe, life-threatening hypersensitivity to a drug?

The term that describes a severe, life-threatening hypersensitivity to a drug is anaphylaxis. This reaction occurs when the immune system overreacts to a substance, leading to symptoms that can include difficulty breathing, swelling, rapid drop in blood pressure, and even loss of consciousness. Anaphylaxis requires immediate medical intervention, typically with the administration of epinephrine, and can occur within minutes of exposure to the allergen.

Anemia relates to a deficiency in red blood cells or hemoglobin and is not directly linked to hypersensitivity or allergic reactions. Shock is a broader term that can refer to a state of insufficient blood flow, which can result from various causes, including but not limited to anaphylaxis. An allergic reaction is a more general term that encompasses a variety of responses to allergens, but it is not specific to the life-threatening nature of anaphylaxis. In summary, anaphylaxis is the specific medical term indicating a severe and rapid hypersensitivity reaction, distinguishing it from other conditions.