What is the dose of Lamictal (lamotrigine) for individuals with borderline personality disorder?

Lamotrigine for Borderline Personality Disorder

Lamotrigine is not FDA-approved for borderline personality disorder (BPD) and has limited evidence supporting its use, though it may help some individuals with affective instability symptoms at doses ranging from 50-200 mg/day. 1

Efficacy and Evidence

• Lamotrigine is approved for maintenance therapy in bipolar disorder in adults, but not specifically for borderline personality disorder. 2

• A small retrospective case review found that lamotrigine at doses of 50-200 mg/day improved symptoms of affective instability in patients with BPD who had failed previous medication trials. 1

• However, a more recent and rigorous randomized controlled trial (RCT) found that lamotrigine (up to 200 mg/day, or 400 mg/day for women taking oral contraceptives) was not clinically effective compared to placebo for BPD symptoms when assessed at 52 weeks. 3

• The conflicting evidence suggests that while some patients may respond to lamotrigine, its overall efficacy for the BPD population is questionable. 3, 4

Dosing Considerations

• For patients who might benefit from a trial of lamotrigine:

  • Starting dose: 25 mg/day 1, 5
  • Gradual titration: Increase by 25 mg weekly 5
  • Target dose range: 50-200 mg/day 1
  • For women taking combined oral contraceptives: Up to 400 mg/day may be needed due to drug interactions 3

• Slow titration is essential to minimize the risk of serious rash, including Stevens-Johnson syndrome. 5

Treatment Alternatives with Better Evidence

• Dialectical Behavior Therapy (DBT) has stronger evidence for treating BPD and should be considered first-line treatment. 2

• DBT has been shown to reduce both nonsuicidal and suicidal self-directed violence among patients with borderline personality disorder. 2

• For pharmacological approaches, the evidence suggests considering:

  • Mood stabilizers like valproate may have better evidence than lamotrigine for symptom management in BPD. 2
  • Atypical antipsychotics may be beneficial for specific symptoms like psychomotor agitation. 2

Clinical Considerations and Monitoring

• Monitor for skin rash, which can be serious and potentially life-threatening (Stevens-Johnson syndrome). 5

• Adherence may be a significant challenge, as demonstrated in the RCT where only 36% of participants assigned to lamotrigine were still taking it at 52 weeks. 3

• Consider comorbid conditions - individuals with BPD and comorbid bipolar disorder might benefit more from lamotrigine than those with BPD alone. 2

• Lamotrigine should be avoided in patients with a history of serious rash reactions to the medication. 2

Common Pitfalls

• Misdiagnosing BPD as bipolar disorder or vice versa can lead to inappropriate treatment choices. Careful differential diagnosis is essential. 2

• Expecting rapid improvement with lamotrigine is unrealistic due to the necessary slow titration schedule to minimize adverse effects. 5

• Relying solely on pharmacotherapy without concurrent psychotherapy (particularly DBT) is less likely to produce meaningful improvements in BPD symptoms. 2

• Discontinuing medication abruptly can lead to withdrawal symptoms or symptom exacerbation. 2