Retirement, failing health and depression may be behind the significant number of over-65s who are taking drug overdoses.

A new study, which tracked reported poisonings among 575 people from their mid-60s onwards over three years, found as many as 37pc had taken deliberate overdoses.

Over half the poisonings had happened accidentally due to problems such as forgetfulness, mental confusion or poor eyesight.

The review of phone inquiries to the National Poisons Information Centre in Beaumont Hospital, Dublin, published in the Irish Medical Journal, found five of the older people died as a result of poisoning.

Cardiovascular drugs, sleeping pills, sedatives and antidepressants were the main drugs used, but bleach, alcohol, pesticides and herbicides were also implicated.

The researchers said the incidence of deliberate self poisoning in older adults exceeded that reported in international studies.

Suicide risk

More women took an overdose than men. "Older adults are considered a serious risk population for suicide. Poisoning is a common method of suicide and older adults are more likely to die from deliberate poisoning than younger people."

Researchers also found that older adults develop more severe symptoms with lower doses of these drugs compared to younger people. They warned that the incidence of poisoning in older people is likely to rise as the population ages and this could impact on our healthcare system.

In addition, they recommended that doctors should try to limit the number of different drugs they prescribe to older people and regularly review the medicines they are taking.

Early recognition and treatment of people suffering from depression may also help reduce the risk of deliberate self poisoning among the elderly. People whose thinking abilities are affected need to be given drugs under supervision and they should be stored safely.

It was also recommended that manufacturers could improve their labelling and warnings, particularly for patients whose eyesight is affected.