A Study Comparing the Efficacy and Tolerability of Ziprasidone vs. Clozapine for the Treatment of Schizophrenia in Patients Who Continue to Have Symptoms on or Cannot Tolerate Other Antipsychotic Drugs

• Drug: Clozapine
  
  Clozapine 25 or 100 mg tablets. Patients were initially titrated over the first 10 days to 300 mg/day and remained at this dose for 1 week. Thereafter, the dose could be varied between 250 and 600 mg/day based on response and tolerability for a total treatment duration of 18 weeks
• Drug: Ziprasidone
  
  Ziprasidone 40, 60, or 80 mg capsules. Patients were initially titrated over the first 3 days to 80 mg/day, which could subsequently be increased to between 80 and 160 mg/day based on response and tolerability for a total treatment duration of 18 weeks
  Other Name: Geodon, Zeldox

• Active Comparator: A
  
  Intervention: Drug: Clozapine
• Experimental: B
  
  Intervention: Drug: Ziprasidone

Inclusion Criteria:

• CGI - S ?4
• PANSS ? 80
• Inpatients or outpatients

Exclusion Criteria:

• Patients with a history of myeloproliferative diseases, history of granulocytopenia, agranulocytosis due to a drug
• Diagnosis of substance dependence within previous 3 months using DSM-IV criteria
• History of seizure
• Organic mental disease, including mental retardation or epilepsy