Which type of reaction is characterized by a severe and immediate allergic response to a drug?

An anaphylactic reaction is characterized by a severe and immediate allergic response to a drug or other allergens. This type of reaction typically occurs within minutes of exposure and can lead to symptoms such as difficulty breathing, swelling of the face and throat, rapid pulse, and a dramatic drop in blood pressure. Anaphylaxis is a medical emergency that requires immediate treatment with epinephrine and may involve additional supportive measures.

Understanding this type of reaction is crucial for pharmacy technicians, as they may be responsible for monitoring patients for potential allergic reactions after the administration of medications. The rapid onset and severity of anaphylaxis differentiate it from other types of allergic reactions and hypersensitivities, which may present with milder symptoms and occur over a longer duration.