Concurrent use of two psychotropic drugs — especially an SSRI and a benzodiazepine — will significantly raise the risk of hip fracture in the elderly, researchers say.

Among patients over 80, initiating these medicines together will lead to one extra hip fracture for every 17 patients treated for a year, according to an article in Australian Prescriber.

There is a lower risk when adding a benzodiazepine when a patient is already on an SSRI but it is still associated with one extra fracture for every 32 patients treated for a year.

GPs and pharmacists from Adelaide say their findings on the number needed to harm are based on previous research into hip fracture odds and medication regimens.