Over-medication could be injuring and killing our elderly.

A University of Otago study has found elderly people taking multiple high-risk medications are twice as likely to fall and break bones, and many die within a year of their injury.

Christchurch researcher Dr Hamish Jamieson says although the right prescription drugs can save lives, we're over-medicating older people.

"Having older people on multiple medications can cause a lot of side effects, and side effects can be bigger than the effects of the medication, so being aware of that is really important."

He says the take-away message for doctors is to make sure they're constantly reviewing what they're prescribing elderly patients.

Dr Jamieson says doctors should look at reducing medications where possible.

"Dome of the medication such as sleeping tablets, patients get used to them and they do help them sleep, but perhaps if they looked at other ways to try and help them sleep such as having a hot bath before bed or quiet music, it may mean they are not reliant on medications and they are not having the long-term side effects."