Adverse drug events

The more medicines a person takes, the more likely they are to have an adverse drug reaction. The proportion of adults with one or more potentially serious drug-drug interactions in their treatment more than doubled in the period from 1995 to 2010. A study found that 80 per cent of patients who were dispensed 15 or more medicines were at risk of a potentially serious interaction.

The same study found that individuals taking multiple medicines were more likely to receive a medicine with anticholinergic activity and the proportion of older people in that population receiving an anticholinergic had grown to 23.7 per cent in 2010, despite increasing evidence of harm from anticholinergic medicines.

Falls

It is often assumed that polypharmacy is related to falls in older people. However, a study reviewing falls in people over 50 years of age taking four or more medicines found that they were not more likely to fall and injure themselves than people taking fewer medicines.

Instead, it was the choice of medicine that was important. If one of the medicines in their regimen was a benzodiazepine, the risk increased by 40 per cent, and taking an antidepressant increased the risk by 50 per cent.

Practice point

Thinking about the causes of polypharmacy, which do you recognise in your community? What role can you play in identifying polypharmacy and how can you go about doing this?

Have you completed the final module in this series on polypharmacy?
Part two: Medicines optimisation in polypharmacy