# Meperidine compared to morphine for rigors associated with monoclonal antibody-related infusion reactions

## TL;DR

This study compares meperidine and morphine for treating rigors during monoclonal antibody therapy, finding both drugs similarly effective and safe.

## Contribution

The study provides the first empirical comparison of meperidine and morphine for MAB-related rigors.

## Key findings

- Both meperidine and morphine required only one dose for rigors ablation in most cases.
- Low rates of sedation and naloxone use were observed in both groups.
- Morphine is a viable alternative to meperidine during drug shortages.

## Abstract

Infusion reactions, characterized by symptoms such as rigors, fever, and hypotension, are common adverse events that occur during monoclonal antibody (MAB) therapy. The treatment of rigors often involves opioids, most commonly meperidine, despite limited evidence supporting use in the setting of MAB infusions. This study aims to compare the efficacy and safety of intravenous (IV) meperidine and morphine is treatment of MAB-related rigors, filling a significant gap in the literature.

This was a single-center, retrospective cohort study which reviewed patients either inpatient or within outpatient infusion centers from January 2015 to January 2024. Patients receiving IV 2 mg morphine or 25 mg meperidine for MAB-related rigors were included. The primary outcome was defined as the number of opioid doses required for rigors ablation. Secondary outcomes included rates of naloxone administration and documented sedation.

A total of 1251 administration events were screened, of which 127 and 26 rigor events were in the meperidine and morphine cohorts, respectively, were included. A majority of both cohorts required only one dose of either agent for rigors ablation with <20% of either cohort requiring 2 or more doses (p = 0.539). Low rates of sedation were observed in both groups.

Both meperidine and morphine effectively manage MAB-related rigors within minimal safety concerns. These findings suggest that morphine is a suitable alternative to meperidine for this indication, which may influence future formulary decision, provide alternatives for drug shortage, and optimize supportive care for patients undergoing MAB therapy.