What can be added to lamictal (lamotrigine) 150mg, Abilify (aripiprazole) 20mg, and gabapentin 300mg TID for a patient with bipolar 2 disorder and increased social anxiety and depression?

Management of Bipolar 2 Disorder with Social Anxiety and Depression

For a patient with bipolar 2 disorder currently taking lamotrigine 150mg, aripiprazole 20mg, and gabapentin 300mg TID who is experiencing increased social anxiety and depression, adding an SSRI (specifically escitalopram or sertraline) would be the most appropriate next step in treatment.

Current Medication Analysis

• Patient is on a reasonable regimen for bipolar 2 disorder with:
  • Lamotrigine 150mg - a mood stabilizer effective for bipolar depression 1
  • Aripiprazole 20mg - an atypical antipsychotic that helps with mood stabilization 2
  • Gabapentin 300mg TID - can help with anxiety but may be at a suboptimal dose for anxiety symptoms 1

Recommended Medication Addition

First-line recommendation: Add an SSRI

• Escitalopram or sertraline would be the most appropriate additions for the following reasons:
  • SSRIs are effective for both social anxiety and depression 1
  • Escitalopram has the least effect on CYP450 isoenzymes compared to other SSRIs, reducing the risk of drug interactions with the current regimen 1
  • Sertraline is also a good option but has some potential for CYP2D6 interactions 1

Dosing and Monitoring Recommendations

• Start with a low dose (e.g., escitalopram 5mg or sertraline 25mg) as a "test dose" 1
• Gradually increase every 1-2 weeks as tolerated 1
• Monitor closely for:
  • Initial anxiety or agitation which can occur early in SSRI treatment 1
  • Signs of hypomania/mania as SSRIs can potentially trigger mood switches in bipolar disorder 1
  • Serotonin syndrome risk, especially when combining with other serotonergic medications 1

Alternative Options

If SSRIs are contraindicated or ineffective:

1. Increase lamotrigine dose

   • Lamotrigine has evidence for efficacy in bipolar depression 3
   • Current dose of 150mg may be suboptimal for some patients 1

2. Increase gabapentin dose

   • Current dose (300mg TID) may be insufficient for anxiety symptoms
   • Higher doses may be more effective for anxiety 4

3. Consider quetiapine augmentation

   • Has demonstrated efficacy for bipolar depression as monotherapy with a large effect size 5
   • May be particularly helpful if sleep disturbance is present

Important Cautions

• Risk of serotonin syndrome when combining SSRIs with other serotonergic agents

  • Monitor for mental status changes, neuromuscular hyperactivity, and autonomic hyperactivity 1
  • Start with low doses and increase slowly 1

• Avoid combining with MAOIs which significantly increases serotonin syndrome risk 1

• Monitor for akathisia when using aripiprazole, especially when combined with lamotrigine and antidepressants

  • Can increase anxiety and potentially suicidal thoughts 6
  • If akathisia develops, aripiprazole may need to be discontinued 6

• Be aware of potential discontinuation syndromes with shorter-acting SSRIs like sertraline 1

Follow-up Recommendations

• Assess response after 4-6 weeks of adequate dosing
• Use standardized symptom rating scales to monitor treatment response 1
• If inadequate response or side effects develop, consider switching to an alternative agent or adjusting doses of current medications

By adding an SSRI with careful monitoring, you can address both the social anxiety and depressive symptoms while maintaining mood stability in this patient with bipolar 2 disorder.