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Vol. LVII, No. 20
October 7, 2005
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Schizophrenia Study Advances Trial Trend

A recent study comparing medications used to treat schizophrenia is the latest example of an emerging type of large-scale clinical effort aimed at finding the most effective ways to treat chronic conditions. Such studies are particularly important as the burden of chronic diseases grows and medical costs continue to soar. The surprise in this study is that the older treatments, which are less expensive than newer ones, may be just as good. It isn't the first study of this type to reach that conclusion.

Schizophrenia is a chronic, recurrent mental illness that brings hallucinations, delusions and disordered thinking to 3.2 million Americans. Antipsychotic drugs were first discovered and used to treat the disease in the 1950s, and increasingly potent drugs with different side effect profiles have been emerging ever since. Second-generation drugs called "atypical" drugs have been touted as being as effective as older drugs while causing fewer side effects. Although the evidence for that hasn't been solid, they now have a 90 percent share of the U.S. market despite being roughly 10 times more expensive.

The CATIE (Clinical Antipsychotic Trials of Intervention Effectiveness) trial was launched by NIMH to compare the effectiveness of antipsychotic drugs. The 18-month study involved more than 1,400 participants at 57 clinical sites around the country. Researchers directly compared an older medication, perphenazine, available since the 1950s, to four newer medications: olanzapine, quetiapine, risperidone and ziprasidone. Their primary outcome measure was discontinued treatment, a definable outcome integrating many factors, including doctors' and patients' judgments about efficacy and side effects, and encompassing real-world complications. Stopping or changing medications is common in people with schizophrenia, so it's a particularly relevant measure.

Unfortunately, none of the drugs lasted the full 18 months of the study for most of the patients taking them. Only 36 percent of those taking the most effective drug, olanzapine, completed the trial. The differences between olanzapine and perphenazine, the older medication, were moderate, and the results for the other atypical drugs were comparable to perphenazine. Olanzapine might therefore seem the best of the antipsychotic drugs at first glance, but patients in the olanzapine group gained an average of 2 pounds per month, more than patients in any other group, and had blood glucose, cholesterol and other measures signaling the development of metabolic syndrome-a serious health condition.

There's clearly a complex series of trade-offs between efficacy, side effects and price among these drugs and this study will help people make more informed decisions about them. Future CATIE reports will address cost-effectiveness, quality of life and other aspects of these medications. CATIE, NIMH says, is part of an overall effort to conduct "practical" clinical trials that address public health issues. It brings to mind NHLBI's ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial), which compared three major classes of medications to treat high blood pressure and found that less costly diuretics are at least as effective as higher-priced drugs.

Given the high costs of health care, these types of head-to-head comparisons will be critical for delivering better, more cost-effective care.

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