But, she said, doctors "should make all efforts to optimize the current regimen for patients" before switching.
Because Zyprexa and Risperdal were widely used when CATIE started in 2000, Dr. Essock and colleagues said, many patients entering the trial were already using them. Such patients were dubbed "stayers" if they were randomly assigned to continue on the same medication. "Switchers" were those who were randomly assigned to either medication from another drug.
Analysis showed that 77 of 314 patients (or 25%) assigned to Zyprexa and 62 of 321 (or 19%) patients assigned to Risperdal were stayers, Dr. Essock said.
The researchers found that Zyprexa stayers had an all-cause discontinuation rate of less than 50%, compared with nearly 70% for those switched to it from another drug drug. Risperdal stayers had a discontinuation rate of about 67%, compared with more than 85% for those switched to it from another drug.