Which condition is characterized by severe, life-threatening hypersensitivity to a drug?

The condition characterized by severe, life-threatening hypersensitivity to a drug is anaphylaxis. Anaphylaxis is a rapid and severe allergic reaction that occurs after exposure to an allergen, which can include certain medications. This reaction can lead to symptoms such as difficulty breathing, swelling of the throat, a rapid drop in blood pressure, and even loss of consciousness. It requires immediate medical attention and treatment, typically with epinephrine, to prevent serious complications or death.

In contrast, while general allergies can cause hypersensitivity reactions, they do not necessarily reach the life-threatening severity of anaphylaxis. Hypersensitivity is a broader term that encompasses various reactions to drugs but does not specifically denote the extreme severity encountered in anaphylaxis. A cumulative effect refers to the increasing response to a drug due to repeated doses over time, which is unrelated to the immediate hypersensitivity responses that define anaphylaxis.