Parkinsonism as a Side Effect of Lamotrigine
Parkinsonism is a documented but uncommon side effect of lamotrigine. While lamotrigine is generally well-tolerated and preferred for its favorable side effect profile compared to older antiseizure medications, it has been associated with various movement disorders including parkinsonism in some patients.
Evidence for Lamotrigine-Associated Parkinsonism
- A literature review identified 13 cases of parkinsonism associated with lamotrigine use among 108 cases of lamotrigine-related movement disorders from 19 countries 1
- Movement disorders associated with lamotrigine typically develop within 6 months of starting the medication in 81% of cases 1
- In most cases (83%), these movement disorders resolve within 1 month after lamotrigine withdrawal 1
Spectrum of Movement Disorders Associated with Lamotrigine
Lamotrigine can cause various movement disorders beyond parkinsonism:
- Tics (29 cases), dyskinesias (21 cases), myoclonus (14 cases), dystonia (10 cases), and akathisia (10 cases) have been reported 1
- Unusual side effects including tremor, unsteadiness, chorea, and eye movement abnormalities have been documented in pediatric patients 2
- These movement disorders typically resolve upon discontinuation of lamotrigine 2, 1
Risk Factors and Clinical Considerations
- The mean lamotrigine dose at movement disorder onset was reported to be 228 mg 1
- Males appear to be more commonly affected than females 1
- Epilepsy was the most common indication for lamotrigine use in patients who developed movement disorders 1
Management of Lamotrigine-Associated Parkinsonism
- The most common and effective management strategy is lamotrigine withdrawal 1
- Careful dose adjustment may be considered before complete withdrawal, evaluating the risk-benefit ratio on a case-by-case basis 1
- When monitoring patients on lamotrigine, clinicians should regularly assess for the emergence of movement disorders 3
Lamotrigine in Clinical Practice
- Despite these potential side effects, lamotrigine is considered a preferred option for seizure control due to its overall good tolerability 3
- Lamotrigine is often preferred over enzyme-inducing antiepileptic drugs because it has fewer drug interactions with steroids, chemotherapy, and targeted therapies 3
- In studies of driving performance, chronic lamotrigine use did not result in clinically meaningful driving impairment, suggesting that cognitive and motor functions are generally preserved with long-term use 3
Contrasting Evidence
- Some research suggests lamotrigine may actually have beneficial effects on parkinsonian symptoms in certain patients with bipolar disorder 4
- However, experimental studies in rat models of Parkinson's disease found that lamotrigine failed to demonstrate antiparkinsonian activity 5
Clinical Monitoring Recommendations
- Patients starting lamotrigine should be monitored for the emergence of movement disorders, particularly within the first 6 months of treatment 1
- If parkinsonism or other movement disorders develop, consider dose reduction or discontinuation of lamotrigine 1
- Regular follow-up visits should include assessment for potential drug-related side effects, including movement disorders 3