Researchers at the Institute for Clinical Evaluative Sciences (ICES), Ontario have shown that short term courses of antipsychotic medications, when given to older adults with dementia, are associated with a greater risk of hospitalisation and death.
Antipsychotic drugs are used to treat various psychotic disorders; some conventional examples include haloperidol or loxaprine. The authors point out that a new generation of these drugs has been released, but the effects of short-term prescription have not yet been ascertained.
"Newer antipsychotic drugs (olanzapine, quetiapine fumarate and risperidone) have been on the market for more than a decade and are commonly used to treat the behavioral and psychological symptoms of dementia," the authors wrote as background information in the article.
"Antipsychotic drugs are often used for short periods to treat agitation in clinical practice. They are frequently prescribed around the time of nursing home admission. About 17 percent of individuals admitted to nursing homes are starting on antipsychotic medication within 100 days, and 10 percent receive only a single prescription. Given the widespread use of short-term prescriptions, it is important to evaluate their safety," they added.
Paula A. Rochon, M.D., M.P.H., F.R.C.P.C., and colleagues studied older adults with dementia living in the community or in nursing homes between 1997 and 2004.
In each setting, the researchers identified three groups of equal size who were identical except for their exposure to antipsychotic medications. Among 20,682 older adults with dementia living in the community, 6,894 did not receive antipsychotics, 6,894 were prescribed atypical or newer antipsychotics and 6,894 were prescribed conventional antipsychotics, such as haloperidol or loxaprine.
Among 20,559 older adults with dementia living in nursing homes, 6,853 received no antipsychotics, 6,853 received atypical antipsychotics and 6,853 received conventional antipsychotics.
Participants' medical records were examined for serious adverse events, defined as hospital admissions and death within 30 days of beginning therapy.
"Relative to community-dwelling older adults with dementia who did not receive a prescription for antipsychotic drugs, similar older adults who did receive atypical antipsychotic drugs were three times more likely and those who received a conventional antipsychotic drug were almost four times more likely to experience a serious adverse event within 30 days of starting therapy," the authors wrote.
"Relative to nursing home residents in the control group, individuals in the conventional antipsychotic therapy group were 2.4 times more likely to experience a serious adverse event leading to an acute care hospital admission or death. Those in the atypical antipsychotic group were 1.9 times more likely to experience a serious adverse event during 30 days of follow-up."
The analysis may underestimate the number of adverse events because of the short length of follow-up, the authors noted. In addition, physicians who notice early signs of a problem may take patients off antipsychotics, avoiding more serious consequences, and many serious events experienced by nursing home residents are dealt with in the facility without hospital admission.
"Our results exploring serious adverse events likely identify only the 'tip of the iceberg.' Antipsychotic drugs should be prescribed with caution even for short-term therapy," they wrote.
The study is published in the May 26 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.