Side effects of painkillers are worse in Alzheimer's

A recent study demonstrates that pain relief drugs produce more pronounced side effects when taken by people with dementia. A second study uncovers why this might be the case.

Roughly 50 percent of people with dementia who are living in nursing homes experience substantial pain. According to earlier studies, this pain often goes unnoticed by clinicians and is therefore poorly managed.

Although paracetamol is generally the first line of treatment for pain, opioids are used when paracetamol is not effective. In fact, around 40 percent of people with dementia living in nursing homes are prescribed opioids.

The team found that side effects such as personality changes, sedation, and confusion were significantly worse in individuals taking opioids, compared with those taking a placebo.

In fact, those who were prescribed the opioid buprenorphine experienced three times the level of harmful side effects. Also, the patients taking buprenorphine were much less active.

"Pain is a symptom that can cause huge distress and it's important that we can provide relief to people with dementia. Sadly, at the moment, we're harming people when we're trying to ease their pain."

Prof. Clive Ballard, University of Exeter Medical School, U.K.

Prof. Ballard's team has also carried out studies on the mechanism behind the increased risk of side effects for people with dementia.

Initially, they were looking at the treatment of arthritis in a mouse model. But along the way, they noticed that mice with Alzheimer's were much more sensitive to the effects of morphine; they needed less for adequate pain relief and experienced worse adverse effects.

They discovered that this was because mice with Alzheimer's release higher levels of the body's natural opioids, such as endorphins.