Related Experiment Video
Updated: Aug 8, 2026

10:22
Basophil Activation Test for Investigation of IgE-Mediated Mechanisms in Drug Hypersensitivity
Published on: September 16, 2011
Anaphylactoid reactions to paracetamol
1Royal Perth Hospital, Perth, Western Australia, Australia. oyekayon@rph.health.wa.gov.au
Postgraduate Medical Journal
|July 25, 2000
Summary
Anaphylactoid reactions to paracetamol, though rare, can be severe even at therapeutic doses. This case highlights the importance of recognizing these adverse drug events beyond typical overdose toxicity.
Area of Science:
- Pharmacology
- Toxicology
- Clinical Medicine
Background:
- Paracetamol (acetaminophen) is a widely used analgesic and antipyretic.
- Overdose toxicity of paracetamol is well-documented.
- Anaphylactoid reactions to paracetamol are infrequently recognized.
Observation:
- A case of a patient experiencing an anaphylactoid reaction to paracetamol is presented.
- The reaction occurred despite the patient not being in overdose quantities.
- This highlights a less common but potentially severe adverse effect.
Findings:
- Adverse reactions to paracetamol, including anaphylactoid responses, can occur even at therapeutic doses.
- These reactions can have life-threatening or near-fatal consequences.
- The infrequent identification of these reactions by healthcare professionals and consumers is noted.
Implications:
- Increased awareness among healthcare providers and the public regarding paracetamol-induced anaphylactoid reactions is crucial.
- Prompt recognition and management of these adverse drug events are essential for patient safety.
- Further research may be warranted to understand the mechanisms and prevalence of paracetamol hypersensitivity.
Related Concept Videos
Allergic Reactions
Overview
Allergic Drug Reactions
Allergic reactions related to drugs are hypersensitivity responses driven by the immune system and bear no connection to the drug's therapeutic action. While drugs in isolation do not trigger an immune response, they can interact with endogenous proteins to form antigens. These antigens stimulate lymphocytes to produce antibodies. IgE-type antibodies attach themselves to mast cells. Upon subsequent exposure to the same stimulus, the antigen-antibody interaction is initiated, unleashing numerous...
Local Anesthetics: Adverse Effects
While local anesthetics are generally safe and well-tolerated, they can occasionally cause adverse effects that vary in severity. Local anesthetics can induce toxicity at two distinct levels. They can either produce local effects through direct contact with the neural elements or be absorbed into the bloodstream from the injection site, leading to systemic effects.
Once absorbed into the systemic circulation, local anesthetics can affect the organs that depend on the functioning of sodium...
Once absorbed into the systemic circulation, local anesthetics can affect the organs that depend on the functioning of sodium...
Drug Toxicity: Allergic Reactions
Drug-related allergies are immune-mediated responses triggered by the administration of pharmacological agents. These hypersensitivity reactions are classified based on the immune mechanisms involved. The four primary types—Type I, II, III, and IV—are mediated by different immunological pathways and exhibit distinct clinical manifestations.Type I Hypersensitivity/ IgE-Mediated Reactions: Immunoglobulin E (IgE) immediately mediates Type I hypersensitivity reactions. Upon initial exposure to a...
Allergic Reactions: Anaphylaxis
Anaphylaxis is a severe, life-threatening hypersensitivity reaction mediated by Immunoglobulin E (IgE) antibodies. When IgE binds to allergens, it triggers the release of mediators– histamine, leukotrienes, and prostaglandins from mast cells and basophils. These mediators cause vasodilation, edema, and inflammation, leading to various symptoms.The primary allergens causing anaphylaxis include food items (e.g., peanuts, shellfish), drugs (e.g., penicillin, asparaginase, corticotropin, heparin),...
Hypersensitivity Reactions: Immune-Complex Reactions
Type III hypersensitivity reactions occur when antigen–antibody complexes form and activate the complement system. Normally, these complexes help the clearance of antigens by phagocytes and red blood cells. However, when large numbers of immune complexes are present, they can deposit in tissues—particularly in the walls of blood vessels—leading to inflammation and tissue injury. These deposits trigger complement activation and neutrophil recruitment, resulting in serum sickness, a systemic...

