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Antipsychotic drugs prescribed in elderly may be dangerous

May 26, 2008 Toronto

Elderly people who take antipsychotic drugs are at an increased risk of having an event that is serious enough to lead to hospitalization or death within a month of starting therapy, says new research from Ontario’s Institute for Clinical Evaluative Sciences (ICES).

The ICES study looked at all Ontario residents aged 66 years and older diagnosed with dementia. 20,682 older adults with dementia lived in the community and another 20,559 matched individuals lived in nursing homes between April 1, 1997 and March 31, 2004. The study looked at the risk of developing serious events that led to hospitalization or death within 30 days of starting the therapy. “It’s a double edged sword,” says lead author and senior ICES scientist, Dr. Paula Rochon, “on one hand the drug may cause serious harm to the frail elderly and on the other, they may make life easier in some very difficult situations. Antipsychotic therapy is widely used to manage behavioral problems in dementia and frequently prescribed around the time of nursing home admission. We need to proceed with caution even when short term therapy is being prescribed, to ensure that the benefits of the drug outweigh the risks for the individual.”

The results:

  • Community dwelling older adults dispensed an atypical antipsychotic therapy were 3.2 times more likely to develop any serious event during the 30 days of follow up compared to those who were not.
  • Those dispensed a conventional antipsychotic therapy were 3.8 times more likely to develop any serious event during the 30 days of follow up.
  • The pattern of serious events was similar but the differences were less pronounced in the nursing home population.
  • Serious events as indicated by a hospital admission or death was frequent following the short term use of antipsychotic therapy in older adults with dementia.
  • Antipsychotic therapy should be used with caution even when short term therapy is being prescribed.

“Our study demonstrates the importance of post-marketing surveillance of new drugs. Clinical trials that are used to determine if drugs are safe before they are licensed often fail to detect problems that occur when these same drugs are used in real world settings by more frail individuals. Studies that look at a wide range of different adverse events in large groups of individuals can provide new and important information. Ongoing safety monitoring of drug side effects in a cohort context, larger real-world populations is vital. Experts from regulatory bodies such as Health Canada, the Food and Drug Administration and drug plans that pay for these drugs will have to consider our findings in the context of all the evidence so far, to decide the future of these drugs. Our results exploring serious adverse events likely identify only the tip of the iceberg,” says Rochon.

Antipsychotics are a group of drugs commonly but not exclusively used to treat psychosis. Conditions for which antipsychotic drugs might be used include schizophrenia, bipolar disorder, mania, and delusional disorder. Over time different classes of antipsychotics have been developed. A first generation of antipsychotics, known as typical antipsychotics, were discovered in the 1950s. Most of the drugs in the second generation of antipsychotics, known as atypical antipsychotics, have more recently been developed and come into use in Alzheimer patients. The Food and Drug Administration (FDA) has ordered manufacturers of atypical, or second-generation, antipsychotic medications to add a new warning to already existing black-box warnings noting that the drugs are associated with an increased risk of death related to psychosis and behavioral problems in elderly patients with dementia.

The study was funded by the Canadian Institutes for Health Research.

Dr. Paula Rochon also practices geriatric medicine and is a senior scientist with Baycrest Geriatric Health Care System in Toronto.

The study “Antipsychotic therapy and short –term serious events in older adults with dementia” is in the May issue of Archives of Internal Medicine.

Author affiliations: ICES (Drs. Rochon, Gill, Anderson, Lipscombe, Bell, Ms. Gomes, Melo, Sykora); Dept. of Medicine, University of Toronto (Drs. Rochon, Lipscombe, Bell); Dept. of Health Policy, Management and Evaluation, University of Toronto (Drs. Rochon, Anderson, Bell); Kunin-Lunenfeld Applied Research Unit, Baycrest (Dr. Rochon); Providence Healthcare, Queen’s University (Drs. Gill); Women’s College Hospital (Dr. Lipscombe); Li Ka Shing Knowledge Institute, St. Michael’s Hospital, (Ms. Melo); Keenan Research Centre, Li Ka Shing Knowledge Institute, (Dr. Bell); St. Michael’s Hospital, Dept. of Medicine (Dr. Bell); Medical Advisory Secretariat, Ministry of Health,(Ms. Gomes) – Ontario; Harvard Medical School – (Dr. Normand); Meyers Primary Care Institute, University of Massachusetts Medical School, Worcester (Dr. Gurwitz) – Boston, MA.

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of health care issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting health care needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.

FOR FURTHER INFORMATION, PLEASE CONTACT:

  • Kristine Galka
  • Media Advisor, ICES
  • 416.480.4780 or 416.629.8493
  • kristine.galka@ices.on.ca

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