"Some antipsychotic medication may increase the risk of death in patients with dementia more than others, according to US research.
The drugs have a powerful sedative effect so are often used when dementia patients become aggressive or distressed.
A study, published on the BMJ website, argued that antipsychotics should not be used "in the absence of clear need".
Experts said better alternatives were needed to antipsychotics.
A study in 2009, suggested 180,000 people with dementia were taking antipsychotic medication in the UK and said the drugs resulted in 1,800 additional deaths.
Researchers at Harvard Medical School followed 75,445 people in nursing homes who had dementia and were prescribed antipsychotics.
The researchers said some drugs were associated with more than twice the risk of death than risperidone, another antipsychotic which was used as a benchmark to compare the other drugs.
The study concluded: "The data suggest that the risk of mortality with these drugs is generally increased with higher doses and seems to be highest for haloperidol and least for quetiapine."
However, the way the study was conducted meant it could not say definitively that certain drugs actually caused more deaths, merely that there was a link between the two.
The Department of Health said antipsychotic use was "resulting in as many as 1,800 unnecessary deaths per year. This is simply unacceptable." (...)"