Effectiveness of Pimozide in Augmenting the Effects of Clozapine in the Treatment of Schizophrenia
Condition: Schizophrenia; Psychotic Disorders
MeSH terms: Schizophrenia; Psychotic Disorders
Study type: Interventional
Phase: Phase 4

Summary: 
      This study will assess the effectiveness of pimozide in enhancing the effects of clozapine in
      the treatment of schizophrenia.
    

Detailed description: 
      A significant number of schizophrenics exhibit partial or no response to typical
      antipsychotic medications. Clozapine has been shown to be more effective in treating
      schizophrenia than typical antipsychotic drugs. However, only an estimated 30% to 60% of
      people who are unresponsive to treatment with typical antipsychotics will respond to
      treatment with clozapine. Taking clozapine with pimozide, an antipsychotic drug, can increase
      clozapine's effects. However, sufficient research on this approach has not yet been
      performed. This study will assess the effectiveness of pimozide in enhancing the effects of
      clozapine in the treatment of schizophrenia.

      Participants in this double-blind study will receive a stable dose of clozapine for eight
      weeks prior to enrollment. For the first 4 weeks following enrollment, baseline measurements
      will be taken. Once a week, participants will report to the study site, where symptom
      severity, cognitive ability, and functional status, including reading level, will be
      assessed. In addition, participants will receive a standard medical examination, which will
      include blood tests and an EKG. Upon completion of this initial phase, participants will be
      randomly assigned to one of two treatment groups: clozapine combined with pimozide; or
      clozapine combined with placebo. This phase will last for 12 weeks. Study visits will
      continue to occur weekly, and will be used to re-assess the measurements obtained during
      baseline. In addition, participants will have an EKG at each study visit for the first 4
      weeks of treatment. All baseline measurements will be repeated in Week 12.
    

Intervention name(s): Pimozide; Placebo
Intervention type(s): Drug; Drug
Intervention description(s): Each capsule of active treatment will contain 2 mg of pimozide. Dosing will be flexible and will range from a minimum of 2 mg per day to 8 mg per day. Dosing will begin at Week 1 with 1 capsule per day. This will be slowly titrated at a rate of 1 capsule per week to a maximum of 4 capsules depending upon clinical response and side effects.; Active drug and placebo will be encapsulated in an identical fashion. The placebo capsule will be made to match in appearance and weight. There will be flexible dosing, allowing a minimum of 1 capsule per day to 4 capsules per day, in order to match the dosing range of the active treatment.
Other intervention name(s): Orap; Sugar Pill
Intervention MeSH terms: Pimozide
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Schizophrenia; Clozapine; Treatment; Combination; Unresponsive; Schizoaffective Disorders