Atypical Antipsychotics May Cause PancreatitisSep 2, 2003 | www.healthyplace.com
A class of widely prescribed antipsychotic medicines called atypical antipsychotics, already under suspicion for causing diabetes, may also precipitate a dangerous inflammation of the pancreas, researchers say.
An analysis of adverse reactions to the medicines reported to the government and in medical journals showed that there were more cases of pancreatitis, an uncommon but potentially fatal condition, among patients taking the newer medicines than those taking haloperidol, an older antipsychotic drug on the U.S. market since 1969.
The difference is provocative, the researchers say, because the 68 million prescriptions written for haloperidol during the study period are more than double the number for any of the newer medicines, the first of which became available in 1991 in the U.S. The report is part of growing body of scientific work suggesting a link between the "atypical" antipsychotic medicines and disorders of the pancreas, including diabetes.
The researchers analyzed reports of adverse reactions from antipsychotic medicines during a 21-year period ending in February 2002. Only six cases of pancreatitis were reported for patients taking only haloperidol, sold as Haldol by Johnson & Johnson. In contrast, there were 53 documented cases of pancreatitis reported for patients taking only Clozapine, the first of the atypical antipsychotics, sold under the brand name Clozaril by Novartis AG.
Among patients taking only Zyprexa, made by Eli Lilly & Co., there were 40 documented pancreatitis cases, and patients taking only Risperdal, also sold by Johnson & Johnson, accounted for 17 documented cases.
A spokesman for Eli Lilly said: "Zyprexa has been used successfully by millions of patients and has a dependable safety and effectiveness profile." He reserved specific comment on the study of pancreatitis until company researchers could review it.
The results appear in the current issue of the medical journal Pharmacotherapy.
The researchers stressed that the risk of an inflamed pancreas from taking any of the antipsychotic medicines is very small. "Nothing in this report should discourage people from appropriate use of atypical antipsychotics, which can be lifesaving for many patients," said P. Murali Doraiswamy, a Duke University psychiatrist and co-author of the study.
Nonetheless, he said the results should alert doctors to a potential difference between haloperidol and the newer antipsychotics.
A Johnson & Johnson spokeswoman said the company agrees with the study's authors that the risks of pancreatitis appear to be quite small, particularly for Risperdal, but agree that further investigation is warranted.
The study was limited by its historical look at reports made voluntarily to the Food and Drug Administration and in the medical literature. Dr. Doraiswamy said doctors may have been more likely to report problems with the atypical antipsychotics because they were newer and less familiar than haloperidol. Also, difficult-to-treat patients are more likely to receive the newer drugs, he said, and some of these people may be more predisposed to pancreatitis due to complicating conditions, such as alcoholism.
"There is a need for more rigorous studies to look for a cause-and-effect relationship," Dr. Doraiswamy said.