Lamotrigine in Patients with Substance Use Disorders
Lamotrigine can be safely and effectively used in patients with substance use disorders, with evidence specifically supporting its use in those with alcohol and cocaine dependence.
Evidence for Lamotrigine in Substance Use Disorders
Alcohol Dependence
- In a 12-week open-label study of 28 patients with bipolar disorder and alcohol dependence, lamotrigine was associated with:
- Significant improvement in mood symptoms
- Decreased alcohol craving
- Reduced alcohol consumption (measured by carbohydrate-deficient transferrin levels)
- Good tolerability with no dropouts due to adverse events 1
Cocaine Dependence
- A similar 12-week study of 30 patients with bipolar disorder and cocaine dependence found:
- Significant improvement in depression, mania, and psychiatric symptoms
- Significant reduction in cocaine cravings
- Good tolerability with no discontinuations due to side effects 2
Clinical Considerations for Prescribing
Dosing and Titration
- Start at low doses (25 mg/day) and titrate slowly to minimize risk of serious rash
- Standard titration involves a 6-week period to reach target dose of 200 mg/day 3
- Dose adjustments required when co-administered with other medications:
Special Considerations for Substance Use Disorder Patients
- For patients with opioid use disorder:
- Collaboration with substance use disorder specialists is strongly recommended when managing pain in these patients 5
- No significant interactions reported between lamotrigine and methadone or buprenorphine
- Unlike benzodiazepines, lamotrigine does not have abuse potential
Monitoring and Safety
- Monitor for development of rash, particularly during initial titration period
- Risk of serious rash (including Stevens-Johnson syndrome) is approximately 0.1% in bipolar patients 3
- Risk factors for serious rash include:
- Rapid dose escalation
- Concurrent valproate use
- Pediatric patients 4
Advantages of Lamotrigine in Substance Use Disorder Population
- Does not require serum level monitoring unlike lithium 3
- Does not cause weight gain, which improves adherence 3
- Low potential for causing sedation or cognitive impairment
- No evidence of abuse potential or withdrawal syndrome
- Can be used as monotherapy or as part of a comprehensive treatment approach
Potential Concerns
- Rare psychiatric side effects have been reported, including:
- Affective switches
- Psychotic episodes
- Hallucinations 6
- These side effects should be monitored, especially in patients with comorbid psychiatric and substance use disorders
In conclusion, lamotrigine represents a valuable treatment option for patients with substance use disorders, particularly those with comorbid bipolar disorder. Its favorable side effect profile, lack of abuse potential, and evidence for reducing cravings make it particularly suitable for this population.