What is the best course of action for managing schizophrenia symptoms in a patient with a history of schizophrenia, currently taking Zyprexa (olanzapine) 15mg and mirtazepine 7.5mg at bedtime, and not in psychosis?

Management of Stable Schizophrenia on Current Regimen

Continue the current regimen of olanzapine 15mg and mirtazapine 7.5mg at bedtime, as the patient is clinically stable without active psychosis, and maintain this antipsychotic treatment indefinitely to prevent relapse. 1

Rationale for Continuing Current Treatment

The American Psychiatric Association strongly recommends (1A evidence) that patients with schizophrenia whose symptoms have improved with an antipsychotic medication continue to be treated with an antipsychotic medication. 1 More specifically, they suggest (2B evidence) continuing treatment with the same antipsychotic medication that achieved symptom control. 1

Your patient's current stability on olanzapine 15mg represents successful symptom management, and discontinuation would carry substantial relapse risk:

• Approximately 65% of patients receiving placebo relapse within 1 year of their acute psychotic phase, compared with only 30% receiving antipsychotics. 1
• Over 5 years, approximately 80% of patients have at least one relapse without maintenance treatment. 1
• This risk is significantly decreased with maintenance antipsychotic therapy. 1

Olanzapine Dosing Assessment

The current dose of 15mg daily is within the therapeutic range (5-20mg/day) and has demonstrated efficacy in multiple controlled trials. 2 Olanzapine at this dose provides:

• Superior efficacy against negative and depressive symptoms compared to conventional antipsychotics. 2
• Significantly fewer extrapyramidal symptoms than haloperidol or risperidone. 2
• No clinically significant hyperprolactinemia or QT prolongation. 2

Mirtazapine Role

The mirtazapine 7.5mg at bedtime likely serves multiple purposes in this regimen:

• Provides sedative effects at this low dose (15mg is the typical starting antidepressant dose). 3
• May offer additional benefit for negative symptoms when used as adjunct therapy, though evidence quality is limited. 4
• The combination of olanzapine and mirtazapine has been used successfully in clinical practice, particularly when comorbid depressive symptoms are present. 5

Ongoing Monitoring Requirements

Metabolic monitoring is essential given olanzapine's metabolic side effect profile:

• Check BMI, waist circumference, and blood pressure at each visit (at least monthly). 6
• Obtain fasting glucose and lipid panel every 3-6 months. 6
• Monitor for weight gain, which occurs significantly more frequently with olanzapine than other antipsychotics. 2

Clinical monitoring should include:

• Monthly physician contact minimum to monitor symptom course, side effects, and medication adherence. 1
• Periodic reassessment of dosage (every 1-6 months) to ensure the lowest effective dose is being used. 1
• Immediate action if worsening symptoms or adverse effects develop. 1

Psychosocial Interventions to Add

The American Psychiatric Association strongly recommends (1B evidence) several evidence-based psychosocial interventions that should be incorporated:

• Psychoeducation about schizophrenia, medication adherence, and relapse prevention. 1
• Cognitive-behavioral therapy for psychosis (CBTp) to enhance coping strategies and reduce distress. 1
• Supported employment services if vocational goals are present. 1
• Family interventions if the patient has ongoing family contact. 1

Critical Pitfalls to Avoid

Do not attempt a medication-free trial unless the patient has been symptom-free for at least 6-12 months and is newly diagnosed. 1 Even then, any evidence of disorder recurrence warrants immediate resumption of treatment. 1

Do not lower the antipsychotic dose without careful monitoring, as this significantly increases relapse risk. 1 Any dose reduction must be gradual and accompanied by frequent clinical assessment.

Do not ignore metabolic side effects, as olanzapine is associated with significant weight gain and metabolic syndrome risk. 2 Consider metformin 500mg daily (increased to 1g twice daily as tolerated) if metabolic concerns develop. 6

When to Consider Treatment Changes

Consider switching antipsychotics only if:

• Intolerable side effects develop despite management attempts. 1
• Metabolic complications become unmanageable. 2
• Symptoms worsen despite adequate adherence. 1

If treatment resistance develops (defined as failure of two adequate trials of different antipsychotics, including at least one atypical agent), clozapine should be initiated. 1 The American Psychiatric Association strongly recommends (1B evidence) clozapine for treatment-resistant schizophrenia. 1