2 Schizophrenia Drugs Square Off
Zyprexa Found More Effective, but Expert Has Concerns
April 7, 2003 -- In a head-to-head comparison of two popular schizophrenia drugs, a new study shows that the most commonly used drug proved to be more effective. But one expert has concerns over Zyprexa's potential long-term side effects.
The study, presented this week at the International Congress on Schizophrenia Research, shows that patients fared better when treated with Zyprexa. That medication was compared with Geodon in 548 people with schizophrenia. Study participants did not know which schizophrenia drug they were getting.
Specifically, the study shows that nearly 60% of patients responded favorably to Zyprexa, compared with 42% treated with Geodon -- having fewer delusions and hallucinations and fewer symptoms of depression. Patients on Zyprexa were also less likely to require additional medications to treat agitation and anxiety or control tremors.
For those who responded to one of the schizophrenia drugs, those taking Zyprexa were less likely to have a relapse throughout the 28-week study. The Zyprexa group was also half as likely to stop taking their schizophrenia drug.
The study was sponsored by Zyprexa manufacturer Eli Lilly and Co., a WebMD sponsor.
"When a patient drops out, it's usually because of side effects, a lack of efficacy, or their psychosis gets worse," says psychiatrist David Garver, MD, of the University of Louisville School of Medicine. "Although the side effects were roughly the same, nearly twice as many patients in the Geodon group dropped out from the study compared to those treated with Zyprexa."
Garver, a spokesman for the American Psychiatric Association, was not involved in the study but he did attend the conference presentation. In his experience, he says both drugs are effective.
"I haven't seen very much of a clinical difference between the two, and it's barely detectable from a practical point of view. But when you get a large number of patients like in this study, the small differences really add up," he tells WebMD. "Overall, this is a good study and demonstrates some further improvement from Zyprexa."
Still, he has his concerns of potential long-term side effects of this schizophrenia drug. "Zyprexa does a beautiful job on the short-term, but it causes the development of diabetes in many patients and raises cholesterol and triglyceride levels," he says. "Unfortunately, these are effects you don't see for years and wouldn't be detected during the course of this study."
In fact, Garver tells WebMD that in Japan, Zyprexa is packaged with special warnings because of these risks. It, along with some other schizophrenia drugs, is also known to cause weight gain, which was seen in 13% of the Zyprexa group, compared with only 2% of those taking Geodon. Both drugs were prescribed to these patients in their usual doses.
"Frankly, although this study gives an edge to Zyprexa, I think what most psychiatrists are concerned about is the ultimate effect of these drugs," says Garver, who has served as a consultant for both Lilly and Pfizer, which manufactures Geodon. "And Geodon doesn't cause these long-term side effects."