Treatment of Schizophrenia and Bipolar Disorder

Introduction to Treatment Options

The American Academy of Child and Adolescent Psychiatry recommends clozapine for treatment-resistant schizophrenia, with a target dose of 300-450 mg/day by the end of 2 weeks, and a maximum dose of 900 mg/day 1
The American Academy of Child and Adolescent Psychiatry suggests that quetiapine is effective as a first-line atypical antipsychotic with efficacy against both positive and negative symptoms comparable to standard antipsychotics, but lacks proven superiority in treatment resistance 1

First-line agents for schizophrenia or bipolar disorder should include amisulpride, risperidone, paliperidone, or olanzapine, with each requiring at least 4 weeks at therapeutic dose before determining efficacy 1
For bipolar disorder in adults, FDA-approved first-line options include lithium, aripiprazole, valproate, olanzapine, risperidone, quetiapine, and ziprasidone for acute mania 2

Clozapine has documented superior efficacy in treatment-resistant schizophrenia, whereas quetiapine's efficacy is comparable to standard antipsychotics 1
In youth with childhood-onset schizophrenia, clozapine was superior to haloperidol, with improvements in both positive and negative symptoms 4

Serious side effects, including the potential for neutropenia and seizures, limit the use of clozapine 3, 4
Weekly white blood cell counts are mandatory for the first 6 months, then every 2 weeks thereafter due to agranulocytosis risk 1

Initiate clozapine at 12.5 mg once or twice daily with slow titration to minimize orthostatic hypotension, bradycardia, and syncope risk, and titrate to achieve plasma level ≥350 ng/mL, with target range of 350-550 ng/mL for optimal efficacy 1, 6

Always co-prescribe metformin with clozapine to attenuate weight gain 1
Monitor for seizures, sedation, hypersalivation, orthostatic hypotension, tachycardia, and metabolic changes 1
If clozapine is contraindicated or not tolerated, consider olanzapine as initial alternative, followed by risperidone or paliperidone 1
Clozapine is generally reserved for treatment-refractory cases in bipolar disorder because of its side-effect profile and should only be used when diagnosis is well established 2