Schizophrenia Treatment Study - Results and Conclusion

CATIE phase 2 pathways - How it will help doctors and people with schizophrenia?

Doctors now have more information to guide the selection of the next antipsychotic medication to try in treating people with schizophrenia if treatment with a first antipsychotic is not successful. The results have shown that the reason why the first medication was stopped is an important consideration in choosing the next medication. Specifically, the success of symptom management and side effects experienced by the patient on the first medication may help predict which medication may be more successful next.

The CATIE results show that for patients whose symptoms are not wholly responsive to other antipsychotic medications, clozapine is an effective choice for the next step. Almost half the patients who took clozapine in phase 2 continued on treatment to the end of the study. Clozapine was more effective at preventing discontinuation because of inadequate control of symptoms than the other three atypicals in this phase: olanzapine, risperidone, or quetiapine. It was also shown to be more effective at reducing the actual level of symptoms than two of the atypicals in this phase: risperidone and quetiapine.

The evidence confirms that clozapine is an effective medication in schizophrenia and the CATIE study results provide further support for efforts directed at both patients and doctors to increase the use of clozapine in the treatment of schizophrenia.

Even with increased support for the use of clozapine, there will still be numbers of patients who need a medication change because their symptoms are not well managed yet do not want to try clozapine. For those patients, CATIE phase 2 results show that olanzapine and risperidone are more effective than ziprasidone and quetiapine. But side effects must be considered.

For patients who stop their first medication because of side effects, there is no clear evidence for switching to one atypical medication over another. Instead, the patient and doctor will best be guided by the nature of the side effects and will have to balance this with the level of symptom control achieved. Olanzapine was associated with substantial weight gain and metabolic problems, more so than the other medications. Ziprasidone was consistently associated with reduction in weight and improvement in metabolic indicators. Risperidone showed the lowest rate of intolerable side effects.

Schizophrenia Treatment Study
Schizophrenia Treatment Study Results
Clozapin Side Effects