# Case report: late adverse reactions in an epilepsy patient on combination therapy with valproate and lamotrigine

## TL;DR

A 54-year-old woman on long-term valproate and lamotrigine therapy experienced late adverse reactions, which were resolved with dosage adjustments and blood drug monitoring.

## Contribution

Highlights previously underreported late adverse reactions to valproate and lamotrigine combination therapy in the Chinese population.

## Key findings

- Late adverse reactions occurred five months after adjusting antiseizure medication.
- Symptoms included dizziness, ataxia, nystagmus, and postural tremors.
- Adjusting drug dosages without medication withdrawal resolved the symptoms.

## Abstract

Late adverse reactions associated with the combined therapy of valproate and lamotrigine are infrequently documented within the Chinese population.

This case report describes a 54-year-old female patient who developed adverse reactions following long-term therapy with valproate and lamotrigine, with symptoms emerging five months after the final adjustment of her antiseizure regimen. The patient presented with symptoms of dizziness, ataxia, nystagmus, and postural tremors. Following blood drug concentration monitoring and subsequent minor dosage adjustments to the antiseizure regimen without medication withdrawal, the patient's symptoms were successfully resolved.

This article underscores the importance of vigilance among clinicians regarding the potential for late adverse reactions and advocates for the proactive monitoring of blood drug concentrations.

The online version contains supplementary material available at 10.1186/s42494-025-00217-3.