Potential anaphylactoid reaction to nicardipine

Area of Science:

• Emergency Medicine
• Clinical Pharmacology

Background:

• Anaphylactic and anaphylactoid reactions are life-threatening allergic responses requiring immediate intervention.
• Nicardipine hydrochloride is a calcium channel blocker used for rapid blood pressure control in hypertensive emergencies.

Observation:

• A 52-year-old male with acute left thalamic hemorrhage presented with severe hypertension (252/135 mmHg).
• Despite hydralazine, blood pressure remained uncontrolled, necessitating a nicardipine hydrochloride infusion.
• The infusion rate was escalated due to persistent hypertension.

Findings:

• While titrating nicardipine infusion, the patient developed localized swelling and erythema at the infusion site.
• Systemic allergic symptoms emerged, including a generalized urticarial rash, tachycardia, diaphoresis, wheezing, and hypoxemia (85% on room air).

Implications:

• This case suggests a potential for nicardipine-induced hypersensitivity reactions, even when used for critical indications.
• Clinicians should be vigilant for allergic responses during nicardipine infusions, particularly with dose escalation.
• Prompt recognition and management of anaphylaxis are crucial for patient outcomes in hypertensive emergencies.