A nursing home drug used to treat agitation and other symptoms of Alzheimer’s disease speeds up cognitive decline, according to a recent study completed by lead researchers from King’s College in London and Oxford University. Results were published online in the British Medical Journal.

The finding is key, study authors say, because quetiapine (brand name Seroquel) has been considered one of the safer antipsychotic drugs. The study suggests that quetiapine is not a viable alternative to two other antipsychotic drugs used to treat agitation in people with dementia – risperidone and olanzapine, which may increase stroke risk.

To derive their results, researchers tracked 93 dementia patients in a randomized double blind placebo controlled trial for six months. Some were given quetiapine, some took a placebo and others were given another antipsychotic drug, rivastigmine (Exelon).

Those who took the placebo showed little change, but those who received quetiapine suffered twice the rate of decline in memory and higher brain functions as those who took the placebo. People who took rivastigmine experienced little or no worsening of their symptoms.