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Back To Vidyya The Clinical Antipsychotic Trials Of Intervention Effectiveness Project (CATIE):

Research Project To Evaluate The Clinical Effectiveness Of Atypical Antipsychotics In The Treatment Of Schizophrenia And Alzheimer's Disease

The Clinical Antipsychotic Trials of Intervention Effectiveness project (CATIE) is a new research project to evaluate the clinical effectiveness of atypical antipsychotics in the treatment of schizophrenia and Alzheimer's disease.

The introduction of antipsychotic drugs in the 1950s heralded the "golden age" of psychopharmacology. Their development compares to the discovery of antibiotics for infectious diseases. Conventional antipsychotic drugs, typified by chlorpromazine and haloperidol, have a proven track record in the treatment of schizophrenia. However, almost a half century of experience has revealed their substantial limitations. They are most effective against the psychotic symptoms of the illness and in its early stages, but their side effects are troubling and contribute significantly to non-compliance, which leads to relapse and rehospitalization. They also do not alleviate all the symptoms and disability caused by the illness, and substantial proportions of these patients continue to be severely disabled and relapse frequently, and require hospitalization.

Although they were first developed for schizophrenia, antipsychotic drugs are now broadly used for other disorders, including behavioral signs and symptoms associated with Alzheimer's disease and other dementias. Despite their widespread use in these conditions, the overall effectiveness and safety of these drugs remain unclear.

The advent of atypical antipsychotic drugs, with their potential for enhanced efficacy and safety, has changed the risk/benefit profile of this drug class. Following the introduction of the first atypical antipsychotic, clozapine, in 1990, several new atypical drugs have become available for clinical use and have now acquired more than 50% of the antipsychotic drug market in the United States. These drugs include risperidone (1994), olanzapine (1996) and quetiapine (1997).

Recent research has provided strong evidence of the efficacy of atypicals in schizophrenia, and demonstrated that they greatly reduce the risk of extrapyramidal side effects. There is a growing belief among clinicians that they are or should become first-line treatments in schizophrenia. However, the exact nature and extent of the clinical advantages of the atypical drugs are not known. Moreover, they cost more than ten times as much as most older drugs. And although a variety of claims of efficacy and safety have been made, they are often based on insufficient evidence. Among the reasons for this is the fact that traditional clinical trials have excluded many patients with schizophrenia, including those who are substance abusers, violent or uncooperative, thus making it difficult to generalize the results of such studies to real world patients. For reasons of external validity, treatment effectiveness studies have sought to use more representative sampling techniques. However, even effectiveness studies rarely have representative samples of providers and systems of care or large enough samples to have sufficient power to examine the role of external factors affecting treatment outcome.

In recent years clinical psychopharmacology research has been dominated by the pharmaceutical industry. While industry-sponsored research is critical to new product development, its emphasis is on meeting regulatory and marketing requirements and on obtaining expanded marketing claims for the drug--not on evaluating the effectiveness of the product at the general population level. As a result, industry-sponsored research does not address broad public health needs or the needs of individual practitioners seeking to make good clinical decisions for individual patients.

Research within a broad public-health perspective is needed, addressing the needs of patients in general, in which exclusion criteria are minimal, outcomes are construed broadly, a wide range of treatment settings are included, and sample sizes are large enough to assure adequate power.

The CATIE Schizophrenia Trial is a randomized controlled trial that will evaluate the effectiveness of atypical and conventional antipsychotic medications in patients with schizophrenia over an 18 month period.

Specific Aims

  1. To determine the long-term effectiveness and tolerability (all-cause treatment discontinuation) of the newer atypical antipsychotics, relative to each other.This will involve contrasting treatment with olanzapine vs. treatment with quetiapine vs. treatment with risperidone vs. treatment with ziprasidone.
  2. To determine the long-term effectiveness and tolerability of the newer atypical antipsychotics relative to a conventional antipsychotic (perphenazine). This will involve contrasting the oral conventional antipsychotic group with the combined newer atypical antipsychotic groups.
  3. To determine, among patients who fail treatment with an initially assigned newer atypical antipsychotic due to lack of efficacy, the long-term effectiveness and tolerability of the other newer atypical antipsychotics, relative to clozapine.
  4. To determine, among patients who discontinue treatment with an initially assigned newer atypical antipsychotic due to treatment intolerance, the long-term effectiveness and tolerability of the other newer atypical antipsychotics, relative to ziprasidone.

The AD trial is a randomized, parallel group, double-blinded study comparing treatment with olanzapine, quetiapine, risperidone, and placebo in AD patients with delusions or hallucinations AND/OR clinically significant aggression or agitation.

Specific Aims

  1. To compare the acute efficacy and effectiveness of risperidone, olanzapine, and quetiapine in treatment algorithms over the course of 36 weeks in treating psychosis in outpatients with Alzheimer's disease
  2. To assess their relative effectiveness at maintaining clinical improvement up to 36 weeks.

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Editor: Susan K. Boyer, RN
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