Opioid Allergy Cross-Reactivity: A Retrospective Study Across Three Opioid Classes

Area of Science:

• Pharmacology
• Immunology
• Clinical Medicine

Background:

• IgE-mediated opioid hypersensitivity (true allergy) is rare; most reactions are side effects or pseudo-allergies.
• Limited literature exists on cross-reactivity among opioid classes due to the rarity of immune-mediated opioid allergies.
• Understanding cross-reactivity is crucial for managing patients with documented opioid adverse drug reactions (ADRs).

Purpose of the Study:

• To determine the rates of cross-reactivity and tolerance among patients with documented opioid allergy or ADRs.
• To assess outcomes of subsequent opioid exposure across natural, semisynthetic, and synthetic opioid classes.
• To evaluate opioid cross-reactivity in a large patient cohort with a history of opioid ADRs.

Main Methods:

• Retrospective study of 1507 patients with documented opioid allergy or ADR at a Veterans Affairs hospital over 10 years.
• Patients were categorized into three cohorts based on the opioid class of their prior allergy/ADR.
• Subsequent opioid exposures were assessed across all three opioid classes for each cohort.

Main Results:

• No cross-reactivity was observed among any of the opioid drug classes.
• 100% re-exposure tolerance rates were found across all study arms.
• This indicates a high likelihood of tolerance when re-challenging patients with different opioid classes after a prior ADR.

Conclusions:

• Opioid hypersensitivity and cross-reactivity are uncommon.
• Patients with a history of opioid allergy or ADR can likely tolerate opioids from different drug classes.
• Findings support increased confidence in using alternative opioid classes for patients with documented opioid allergies or ADRs.