Elderly patients who are prescribed a conventional, or first-generation, antipsychotic medication are at an increased risk of death from cardiovascular or respiratory diseases as compared to those who take an atypical, or second-generation, antipsychotic medication, according to a study funded by the Agency for Healthcare Research and Quality.

The new study, "Potential Causes of Higher Mortality in Elderly Users of Conventional and Atypical Antipsychotic Medications," recently posted online in the Journal of the American Geriatrics Society, adds to growing evidence that conventional antipsychotics may not be safer than atypical anitpsychotics for the elderly. Researchers had previously identified that such second-generation medications may pose increased mortality; the new study compares specific causes of death among elderly patients newly started on conventional vs. atypical antipsychotics.

In 2005, after studies suggested second-generation antipsychotics increased the risk of death by 60 percent in elderly patients with dementia, the FDA issued a public health advisory, which did not extend to first-generation antipsychotics. The new study, however, provides additional evidence of the risks associated with first-generation versions for elderly patients. While this study does show an association with cardiovascular deaths, further studies will be needed to confirm this association.

Authors examined records of all seniors in British Columbia who took either first-generation or second-generation antipsychotics between 1996-2004, including 12,882 patients who commenced use of conventional and 24,359 patients who began a regimen of atypical antipsychotic medications. Of 3,821 total deaths within the first 180 days of use, cardiovascular deaths accounted for 49 percent of the excess deaths.

The study was completed by researchers at the Brigham and Women's Hospital DEcIDE (Developing Evidence to Inform Decisions about Effectiveness) team in Boston. That team is one of 13 nationwide that are part of the AHRQ's Effective Healthcare (EHC) program.