# Incidence of somnolence and dizziness induced by mirogabalin and pregabalin under opioid treatment: a single-center observational study

## TL;DR

This study compares how often mirogabalin and pregabalin cause drowsiness and dizziness in cancer patients taking strong opioids.

## Contribution

The study provides new evidence on the comparative safety of mirogabalin versus pregabalin in opioid-treated cancer patients.

## Key findings

- Mirogabalin patients experienced drowsiness and dizziness sooner than pregabalin patients.
- Pregabalin was associated with increased opioid use, while mirogabalin was not.
- Both drugs require careful monitoring for central adverse effects in opioid-treated patients.

## Abstract

The gabapentinoids pregabalin and mirogabalin are utilized to treat neuropathic pain, especially in patients with cancer receiving opioid analgesics. Pregabalin combined with strong opioids increases somnolence and dizziness, while mirogabalin causes fewer central adverse events. This study aimed to determine whether mirogabalin leads to a lower incidence of somnolence and dizziness than pregabalin in patients with cancer receiving strong opioids.

We analyzed inpatients with cancer treated with mirogabalin or pregabalin along with strong opioids at Fujita Health University Hospital (April 2019–December 2023) and assessed cumulative incidence rates, hazard ratios (HRs) for somnolence and dizziness occurrence, and changes in morphine milligram equivalents (MMEs).

Among the 89 patients included in the analysis (mirogabalin: 39, pregabalin: 50), the median time to somnolence and dizziness was significantly shorter in the mirogabalin group than in the pregabalin group (8.0 vs. 17.0 days, p = 0.039). The multivariable Cox proportional regression model showed a higher risk with mirogabalin, although with no significance (HR: 1.74, p = 0.117). MMEs increased in the pregabalin group but not in the mirogabalin group.

Mirogabalin and pregabalin contribute to somnolence and dizziness in patients receiving strong opioids, necessitating careful monitoring.

The online version contains supplementary material available at 10.1186/s40780-025-00464-z.