Older adults who take certain medications such as antidepressants and sleeping pills are at greater risk of a fall that could hasten their death, say Canadian researchers.

A fall for a senior is more than just painful; falls can also permanently rob seniors of their independence and are the fifth-leading cause of death in seniors in the developed world, say the authors published in this week's issue of the Archives of Internal Medicine.

The researchers from the University of British Columbia say many of the medications that are routinely prescribed to seniors could be leading to many of these falls.

The team, led by Dr. Carlo Marra, a UBC pharmacist and epidemiologist, looked at 22 international studies involving more than 79,000 study participants older than 60. They found that seniors on antidepressants, antipsychotics and sedative-hypnotics were 1.5 times more likely to have a fall compared to those not taking the medications.

Antidepressants had the strongest association with falls, possibly because older drugs in this class have significant sedative properties.

Anti-psychotics -- often used to treat schizophrenia and other psychoses -- and benzodiazepines, such as Valium, also has a strong link to falls, the researchers report.

Surprisingly, the use of non-steroidal anti-inflammatories (NSAIDS), such as ASA and ibuprofen, also increased the likelihood of a fall even though the medications have no sedative effect.

The authors suspect that in those cases it may not be the medications themselves that lead to falls, but rather the conditions that required the pain relievers, such as osteoarthritis in the knee.

And yet, narcotic painkillers were found not to be statistically associated with falling. That finding requires further research, says Marra, who is also a member of the Centre for Hip Health and Mobility, part of Vancouver Coastal Health Research Institute.

Other medications that increased the risk for falls include drugs that reduce blood pressure.

Marra says there may be many reasons why elderly people have trouble with some medications.

"Elderly people may be more sensitive to drugs' effects and less efficient at metabolizing medications, leading to adverse events, which in turn lead to falls," he noted.

The authors say their findings suggest that doctors need to take more care in prescribing for seniors.

"These findings reinforce the need for judicious use of medications in elderly people at risk of falling," Marra said.

"Safer alternatives, such as counselling, shorter-term or less-sedating therapies, may be more appropriate for certain conditions."

One in three Canadians over 65 living at home experiences a fall each year. For those over age 80, that figure rises to 40 per cent.

Almost all hip fractures -- about 90 per cent -- are caused by falls. And among seniors living at home who fracture a hip, one in five will die within a year while 15 per cent will have to move into a long-term care facility.

Determining which medications increase the risk of falls remains a challenge since seniors are often on multiple medications and new drugs enter the market on a regular basis, says Marra.

In follow-up research, he aims to explore how pharmacists can identify patients at risk of falling and educate them about medication use to ensure their safety.