Can I safely discontinue Seroquel (quetiapine) and maintain only olanzapine in a patient with schizophrenia whose hallucinations have resolved after B12 level improvement?

Managing Antipsychotic Therapy in a Patient with Schizophrenia After Symptom Resolution

You should gradually taper quetiapine while maintaining olanzapine as monotherapy, as this approach minimizes the risks associated with antipsychotic polypharmacy while ensuring continued symptom control. 1

Assessment of Current Situation

• 35-year-old female with schizophrenia
• Currently on dual therapy: quetiapine 400mg at bedtime and olanzapine 15mg
• History of severe psychosis for over 10 years
• Hallucinations have resolved after B12 level improvement
• Patient is currently stable

Rationale for Tapering to Monotherapy

The American Psychiatric Association (APA) guidelines strongly recommend that patients with schizophrenia whose symptoms have improved with an antipsychotic medication continue to be treated with the same antipsychotic medication (1A recommendation) 1. However, there is limited evidence supporting the long-term use of antipsychotic polypharmacy.

The 2021 guidelines on antipsychotic polypharmacy suggest that when a patient has improved and attained a stable condition, slowly and carefully reverting back to antipsychotic monotherapy should be considered, as many patients seem to be able to tolerate this change 1.

Recommended Approach

1. Maintain olanzapine as the primary antipsychotic

   • Olanzapine is an effective atypical antipsychotic for schizophrenia
   • APA guidelines suggest continuing with the same antipsychotic when symptoms have improved 1

2. Gradual tapering of quetiapine

   • Begin with a 25% dose reduction (reduce to 300mg at bedtime)
   • Monitor for 2-4 weeks for any symptom re-emergence
   • If stable, reduce by another 25% (to 200mg)
   • Continue stepwise reduction (100mg, then 50mg) with 2-4 weeks monitoring at each step
   • Discontinue completely if patient remains stable throughout the process

3. Monitoring during tapering

   • Watch for re-emergence of psychotic symptoms
   • Monitor sleep patterns (quetiapine has sedative properties)
   • Assess for withdrawal symptoms

Considerations for Choosing Olanzapine Over Quetiapine

1. Efficacy profile

   • Both medications have similar efficacy in schizophrenia 2
   • Olanzapine has shown good efficacy for negative symptoms 3

2. Dosing convenience

   • Olanzapine can be effectively administered once daily
   • Quetiapine has a shorter half-life (approximately 7 hours) and often requires twice-daily dosing for optimal effect 4

3. Patient history

   • The patient has been stable on the current regimen, suggesting both medications are effective
   • Maintaining one of the current medications reduces the risk of destabilization

When to Reconsider the Tapering Plan

If during the tapering process any of the following occur:

• Re-emergence of hallucinations or delusions
• Increased agitation or anxiety
• Significant sleep disturbance
• Any signs of psychotic decompensation

In such cases:

• Return to the previous stable dose of quetiapine
• Reassess the tapering schedule (consider a slower taper)
• If symptoms persist despite returning to the previous dose, consider maintaining both medications

Long-term Monitoring

• Regular follow-up appointments (initially monthly, then quarterly if stable)
• Monitor for metabolic side effects of olanzapine (weight gain, glucose abnormalities, lipid changes)
• Annual physical health monitoring including metabolic parameters
• Continue monitoring B12 levels, as deficiency was associated with previous hallucinations

Important Caveats

• If the patient has been stable on dual therapy for 10 years, any medication changes should be approached with caution
• The resolution of hallucinations after B12 correction suggests a potential metabolic component to her symptoms
• If symptoms worsen during the taper, reverting back to the dual antipsychotic regimen is appropriate 1
• Document the rationale for medication changes and the patient's response carefully

This approach balances the goal of medication simplification with the need to maintain symptom control in a patient with a long history of severe psychosis.