Newer drugs for schizophrenia can interfere with potassium metabolism, putting the heart at risk. These drugs have a greater fatal heart attack rate. (Louise Valentine/The Epoch Times)
The drugs are among the best selling in the world, and some experts suggested that the common practice of using them for unapproved purposes such as dementia and childhood hyperactivity should be sharply curtailed.
Dr. Wayne Ray of the Vanderbilt University School of Medicine and colleagues studied nearly 277,000 people in Tennessee and found patients taking the highest dose had the greatest risk, and the danger faded once they stopped taking the drugs.
Ray said the findings do not necessarily mean people should stop taking their drugs. In some cases, there are no good alternative treatments.
“Any prescription is a balancing of risks and benefits. This is more information on the risks that needs to be taken into account,” Ray said in a telephone interview.
“Many people thought the ‘atypicals’ would be much, much safer. Our study suggests that they are not at all safer in regards to this serious end point,” said Ray.
In June the U.S. Food and Drug Administration said older, conventional antipsychotic medications should carry a warning on the packaging about the risk of death.
The FDA issued a similar warning in 2005 for newer antipsychotics such as Bristol-Myers Squibb Co.’s and Otsuka Pharmaceutical Group’s Abilify and Eli Lilly and Co.’s Zyprexa, known generically as olanzapine.
Using files from the Tennessee Medicaid program for the poor, the researchers confirmed that the rate of fatal heart attacks was twice as high among those taking the drugs.
“A similar increased risk was seen for current users of atypical antipsychotic drugs, who had a rate of sudden cardiac death that was more than twice that for nonusers,” they wrote.
The drugs studied in this group included clozapine, made generically, Johnson & Johnson’s Risperdal, or risperidone, Zyprexa, and quetiapine, made by AstraZeneca under the brand name Seroquel.
Zyprexa, Risperdal, and Seroquel are among the 10 top-selling drugs worldwide, with a combined sales volume of $14.5 billion in 2007. Lilly and AstraZeneca did not immediately respond to requests for comment.
The drugs can interfere with the flow of potassium, which the heart needs to function properly.
Ray said that in spite of the risks, there are no good alternatives for schizophrenia and other serious psychoses. “The take-home message from our study is for these diseases you would first want careful testing, like an EKG (electrocardiogram) and a cardiovascular workup,” he said.
The antipsychotics are often prescribed for bipolar disorder, anxiety, depression, and attention-deficit hyperactivity disorder (ADHD), even though the FDA does not approve their use for those purposes.
In a commentary, Drs. Sebastian Schneeweiss and Jerry Avorn of Brigham and Women’s Hospital in Boston said there was much less evidence that the drugs work for unapproved purposes, particularly for children and in the elderly with dementia.
“For these patients, the use of antipsychotic medications should be reduced sharply,” they wrote.
