What dose of Celexa (citalopram) should be started for a patient with bipolar disorder on Vraylar (cariprazine) 3mg, who has a history of responding well to Celexa, but also experiences severe anxiety?

Starting Citalopram in a Patient with Bipolar Disorder on Vraylar

For a patient with bipolar disorder on Vraylar (cariprazine) 3mg who has predominant depression with severe anxiety and previous good response to Celexa, start at 10mg of citalopram daily and monitor closely for symptom improvement and potential mood destabilization.

Rationale for Citalopram Selection and Dosing

Citalopram (Celexa) is an appropriate choice for this patient given their:

• Previous positive response to citalopram
• Current symptoms of depression and severe anxiety
• Stabilization on Vraylar (cariprazine) 3mg for bipolar disorder

Initial Dosing Strategy:

• Starting dose: 10mg daily 1
• Maximum dose: 40mg daily (though rarely needed in this population)
• Administration: Can be given morning or evening

This low starting dose is particularly important because:

1. The patient has bipolar disorder (risk of mood switch)
2. The patient is already on an antipsychotic medication
3. Lower doses minimize initial side effects while allowing assessment of response

Monitoring and Titration Plan

First 2-4 Weeks:

• Monitor for activation, agitation, or signs of mania/hypomania
• Assess for improvement in depressive and anxiety symptoms
• If no improvement after 2 weeks and no adverse effects, consider increasing to 20mg daily

Weeks 4-6:

• Evaluate response using standardized measures
• If partial response at 10mg with good tolerability, consider increasing to 20mg
• If good response at 10mg, maintain this dose

Important Considerations:

• Maintain the Vraylar 3mg dose as it provides mood stabilization and has demonstrated efficacy for bipolar depression 2, 3
• Cariprazine's D3/D2 partial agonist properties may help reduce the risk of antidepressant-induced mania 2
• Citalopram has shown efficacy for both depression and anxiety at doses as low as 10mg 4, 5

Potential Side Effects and Management

Common Side Effects to Monitor:

• Gastrointestinal disturbances (nausea, diarrhea)
• Sleep disturbances
• Sexual dysfunction
• Increased anxiety initially

Serious Concerns:

• Risk of mood switch: The most significant concern when adding an antidepressant to a bipolar patient's regimen
• QTc prolongation: Monitor in patients with cardiac risk factors (citalopram doses >20mg have greater risk)

Special Considerations for Bipolar Depression

Antidepressant monotherapy should be avoided in bipolar depression 6, which is why:

• Maintaining the Vraylar 3mg is essential
• Starting at a low dose of citalopram (10mg) is prudent
• Close monitoring for mood switches is necessary

Evidence for This Approach

The recommended starting dose of 10mg daily is supported by guidelines showing that:

• SSRIs should be initiated at lower doses in patients with bipolar disorder 1
• Citalopram specifically has an initial recommended dose of 10mg daily 1
• Early improvement with cariprazine plus an antidepressant can predict eventual treatment response 7

This approach balances the need to address the patient's depression and anxiety while minimizing the risk of mood destabilization in the context of bipolar disorder.