Anaphylaxis following intravenous paracetamol: the problem is the solution

Area of Science:

• Anesthesiology
• Clinical Immunology
• Pharmacology

Background:

• Paracetamol (acetaminophen) is a common analgesic and antipyretic.
• Intravenous administration is frequent in perioperative settings.
• Immediate hypersensitivity reactions are exceptionally rare.

Observation:

• Two cases of anaphylaxis to intravenous paracetamol are presented.
• Episodes occurred in diverse perioperative settings.
• Patients had no prior history of intolerance to oral paracetamol.

Findings:

• Allergological investigations identified mannitol as the causative agent.
• Mannitol is an excipient in the intravenous paracetamol formulation.
• Neither patient showed allergy to paracetamol (acetaminophen) itself.

Implications:

• Perioperative drug hypersensitivity requires thorough investigation.
• Excipients, not just active ingredients, can trigger anaphylaxis.
• Accurate diagnosis is crucial for patient safety and future anesthetic management.