Evaluation of the Strategies of Switching Schizophrenia Patients to Aripiprazole From Other Antipsychotic Agents
Condition: DSM-IV Schizophrenia; Schizoaffective Disorder
MeSH terms: Schizophrenia; Psychotic Disorders
Study type: Interventional
Phase: Phase 4

Summary: 
      The purpose of this study is to determine whether moderately ill Asian schizophrenic patients
      can be switched from their previous antipsychotic medication to aripiprazole with minimal
      adverse clinical consequences, and elucidate both pharmacokinetic and pharmacodynamic factors
      associated with clinical efficacy of aripiprazole.
    

Detailed description: 
      Aripiprazole (commercial name abilify) is the first commercially available drug with dopamine
      partial agonist effects approved for the treatment of schizophrenia and bipolar disorder
      since 2002 in the U.S. It reduces negative symptoms of schizophrenia efficiently and has a
      markedly lower incidence of extrapyramidal symptoms and tardive dyskinesia. However, the
      process of switching other antipsychotic agents to aripiprazole can result in a re-emergence
      or worsening of psychosis, along with unpleasant side effects such as insomnia, nausea,
      vomiting, anxiety and agitation. On the basis of a prior study demonstrating the efficacy and
      safety of aripiprazole in Taiwan population, we hence propose to apply a combined use of
      pharmacogenomics and therapeutic drug monitoring in the evaluation of the strategies of
      switching stable schizophrenia patients to aripiprazole from other antipsychotic agents.

      We will evaluate their cytochrome P450 background along with other potential candidate genes
      of schizophrenia. This 2-year proposal will examine the relative efficacy, safety and
      tolerability of two different strategies for switching stable inpatients/outpatients from
      prior antipsychotic monotherapy to aripiprazole 15 mg/day monotherapy using two different
      strategies:

        1. Fast tapering of the previous medication within 1 week after initiating aripiprazole for
           2 weeks.

        2. Slow tapering of the previous medication within 4 weeks after initiating aripiprazole
           for 2 weeks.

      A total of 200 stable schizophrenia patients will be randomized with open label to two
      strategies.

      We expect to achieve the following results:

        1. Developing a protocol that has high probability of switching successfully schizophrenia
           patients to aripiprazole, which is effective in treatment refractory cases and has a
           markedly lower incidence of severe side effects, from other antipsychotics.

        2. Elucidate both pharmacokinetic and pharmacodynamic factors associated with clinical
           efficacy of aripiprazole.
    

Intervention name(s): Aripiprazole
Intervention type(s): Drug
Intervention description(s): Aripiprazole will be given as a fixed does, 15 mg/day, orally throughout 8 weeks in the 2 arms.
Other intervention name(s): abilify
Intervention MeSH terms: Aripiprazole
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: Aripiprazole; schizophrenia; antipsychotics; pharmacogenomics; cytochrome P450 enzyme