A landmark government-financed study that compared drugs used to treat schizophrenia has confirmed what many psychiatrists long suspected: newer drugs that are highly promoted and widely prescribed offer few – if any – benefits over older medicines that sell for a fraction of the cost.
The study, which looked at four new-generation drugs, called atypical antipsychotics, and one older drug, found that all five blunted the symptoms of schizophrenia, a disabling disorder that affects 3 million Americans.
But almost three-quarters of the patients who participated stopped taking the drugs they were on because of discomfort or specific side effects.
One of the newer drugs, Zyprexa, from Eli Lilly, helped more patients control symptoms for significantly longer than the other drugs. But Zyprexa also had a higher risk of serious side effects – such as weight gain – that increase the risk of diabetes.
The study, released Monday and to be published Thursday in the New England Journal of Medicine, was widely anticipated because it is by far the largest, most rigorous head-to-head trial of the newer antipsychotics conducted without significant drug-industry financing. The new drugs account for $10 billion in annual sales and 90 percent of the national market for antipsychotics.
The findings may not significantly alter the prescribing patterns of doctors in private practice, who often do not have to worry about cost, psychiatrists said. But they are likely to have an enormous effect on state Medicaid programs, many short on funds in part because of the high cost of schizophrenia drugs.
The government study set out to judge each drug by how long patients and their doctors continued the therapy, a criterion rarely used in studies by drugmakers but crucial in real-world practice.
People with schizophrenia struggle with delusional thoughts, private voices, blunted emotions and other symptoms, and most try multiple drugs in trying to avoid severe side effects.
The researchers, led by psychiatrist Jeffrey Lieberman, now at Columbia University, recruited 1,493 people with the disorder and assigned them to one of five drugs: Risperdal, from Johnson & Johnson; Seroquel, from AstraZeneca; Geodon, from Pfizer; Zyprexa; and an older drug, perphenazine.
The study found that at more modest doses, the older drug, perphenazine, while just as effective, was not significantly more likely to cause neurological symptoms.
Lieberman said that there was no reason to believe that modest doses of other older drugs, such as Haldol, would perform differently.
In the doses used in the study, a month’s supply of perphenazine costs about $60, compared with $520 for Zyprexa, $450 for Seroquel, $250 for Risperdal and $290 for Geodon.