Neuropathic pain drugs found to increase risk of hip fracture in older adults

Often seen as a safer alternative to opioids for the treatment of neuropathic pain, gabapentinoid use increased eightfold between 2012 and 2018, with one in seven Australians aged 80 and older prescribed a gabapentinoid during this period.

Currently, gabapentinoids are within the ten most subsidised medications by volume in Australia.

Study co-author and Director of the Centre for Medicine Use and Safety (CMUS) at the Monash Institute of Pharmaceutical Sciences, Professor Simon Bell, said gabapentinoids can be effective for neuropathic pain but can also result in adverse events including dizziness, gait disturbance and balance disorder.

The researchers analysed the data for 28,293 patients who experienced hip fractures across a five-year period.

"Our results showed patients had 30 per cent increased odds of suffering a hip fracture within two months of being dispensed a gabapentinoid medication," Professor Bell said.

"The link between gabapentinoids and hip fractures existed across different age groups but the odds of hip fracture was higher among patients who were frailer or had chronic kidney disease, so these should be important considerations when deciding when to prescribe gabapentinoids."

However, Professor Bell stressed the importance of patients discussing with their doctor or pharmacist first before deciding to discontinue treatment.

This is the first study to specifically observe a higher odds of hip fractures in frail patients dispensed gabapentinoids as against patients who are not frail.

Lead author of the study and CMUS PhD candidate Miriam Leung, said the study highlights that caution is needed before prescribing gabapentinoids, especially for people who are prone to falls and fractures.

"Our findings highlight the importance of assessing each patient's risk before prescribing gabapentinoids," Ms Leung said.

The researchers said further studies are needed to investigate the risk of hip fracture with different dosages of gabapentinoids and with different degrees of kidney impairment.

The researchers are currently working with the University of Eastern Finland to investigate hip fractures in patients with Parkinson's disease.

This research was a collaboration between CMUS and researchers from Austin Health and Harvard Medical School. Data acquisition was funded via the Dementia Australia Research Foundation's Yulgilbar Innovation Grant.

Centre for Medicine Use and Safety Director and co-author of the paper, Professor Simon Bell, is available for interviews.