The US Food and Drug Administration (FDA) has warned of an unapproved (off-label) use of certain drugs called "atypical antipsychotic drugs."

It has issued a public health advisory to alert health care providers, patients, and patient caregivers to new safety information concerning such usages.

These drugs are approved for the treatment of schizophrenia and mania, but clinical studies of these drugs to treat behavioural disorders in elderly patients with dementia have shown a higher death rate associated with their use compared to patients receiving a placebo (sugar pill), FDA says in a release.

This advisory applies to such antipsychotic drugs as Abilify (aripiparozole), Zyprexa (olanzapine), Seroquel (quetiapine), Risperdal (risperidone), Clozaril (clozapine) and Geodon (ziprasidone). Symbyax, which is approved for treatment of depressive episodes associated with biopolar disorder is also included in the agency's advisory.

FDA is requesting that the manufacturers of all of these kinds of drugs add a boxed warning to their drug labelling describing this risk and noting that these drugs are not approved for the treatment of behavioural symptoms in elderly patients with dementia. Patients receiving these drugs for treatment of behavioural disorders associated with dementia should have their treatment reviewed by their health care providers.

In analyses of seventeen placebo-controlled studies of four drugs in this class, the rate of death for those elderly patients with dementia was about 1.6 to 1.7 times that of placebo. Although the causes of death were varied, most seemed to be either heart-related (such as heart failure or sudden death) or from infections (pneumonia).

The agency is considering adding a warning to the labelling of older antipsychotic medications because limited data also suggest a similar increase in mortality for these drugs. The review of the data on these older drugs, however, is still on-going, the release says.