Age and sex influence the adverse effects of multiple medications

There are calls for a carefully-considered, tailored approach to the prescription of multiple medicines with new research finding a person’s age and sex influence the impact of multiple medications.

More than half of older Australians take five or more regular medications, with the higher number of medications directly linked to a higher chance of adverse reactions, like falls, confusion and frailty.

Researchers from the Ageing and Pharmacology Laboratory at the Kolling Institute, led by Professor Sarah Hilmer, used an experimental model to measure the impact of multiple medications, including high risk drug classes.

The research confirmed the multiple medications had an adverse impact, reducing independence in daily living, increasing anxiety and reducing physical function including grip strength, motor endurance and gait speed.

Further analysis found the negative impacts were influenced by age and sex.

The decline in independence and increase in anxiety were significantly greater in the old than in the young, while males were more likely to experience reduced grip strength than females.

Professor Hilmer said this was an important body of research and the first study to rigorously assess the effects of age and sex on susceptibility to the adverse impacts of multiple medications.

“The research indicates that a one-size fits all approach to the prescription of multiple medications is not advised, and the differences in age and sex should be considered,” she said.

“To get the best outcomes from medications, we need to practice personalised medicine.

“It’s important to consider not only the person’s diagnosis, but also their age, sex, other medications, other diseases, genetic and environmental factors.

“We would particularly like to see a more cautious approach when multiple medicines are prescribed for older people.”

Co-first author Dr John Mach said further studies are needed to investigate the impact of a broader range of medications.

“While males were more susceptible to the regimen we tested, females may be more susceptible to other drug classes.

“Our study highlights the need for further investigations to ensure medication use across Australia is supported by scientific evidence.”

Dr Harry Wu, who was also a co-first author, hopes the study will be the first of many to promote a more personalised approach to medication use.

“It has been exciting to have the opportunity here at the Kolling to conduct this bedside to bench research, to help understand how to treat and monitor patients who take multiple medicines.”