Common Painkillers Could Cause Harmful Side Effects in Dementia Patients: Study

Common painkillers could cause harmful side effects in people with dementia, according to research.

Scientists based in the U.K. and Norway found opioid-based drugs were linked to negative side effects including personality changes, confusion and sedation in patients with dementia.

The findings of the two studies into dementia are set to be presented at the Alzheimer's Association International Conference 2018 this week, and therefore have not been peer reviewed.

Rather than a single disease, dementia is an umbrella term used to describe disorders that cause symptoms including debilitating memory problems and a decline in thinking skills. The most common form of dementia is Alzheimer's, which an estimated 5.7 million Americans currently live with.

Researchers found painkillers can cause harmful side effects in patients with dementia. As dementia affects a person’s ability to communicate, managing pain can be particularly difficult. Getty Images

Around half of people with dementia who live in care homes experience some form of significant pain, for instance from unrelated conditions such as arthritis. But the pain often goes under-diagnosed and is poorly managed when it is caught, past studies have shown. Paracetamol (acetaminophen) is usually the first-choice painkiller for clinicians, followed by opioid treatments, the authors noted.

As it becomes harder for dementia patients to communicate, treating their pain can be difficult. As such, researchers at the University of Exeter, U.K., King's College, U.K, and the University of Bergen, Norway, wanted to understand the effect opioids have on these patients.

In a study led by the University of Bergen, the team conducted a randomized control trial of 162 residents of 47 Norwegian care homes who were diagnosed with advanced dementia and depression. Patients with severe pain were excluded.

The results revealed those who were given the opioid buprenorphine (which is prescribed to up to 15 percent of dementia patients in countries where the drug is available) saw their risk of experiencing negative side effects triple from the baseline, compared to those who took acetaminophen or a placebo. These patients were also significantly less active than others, the authors said.

In a separate study in mice with arthritis led by the University of Exeter Medical School, scientists found rodents with a disease comparable to Alzheimer's responded to lower doses of morphine to ease pain than those without the neurodegenerative disorder. They also suffered worse side effects compared with control mice when their dose were raised. The mice given morphine also produced more endorphins and other types of the body's natural painkillers, the authors found.

The team concluded the dose of opioid painkillers given to those with dementia must be reviewed.

Professor Clive Ballard of the Age-Related Diseases department at the University of Exeter Medical School said in a statement: "Sadly at the moment, we're harming people when we're trying to ease their pain. We urgently need more research in this area, and we must get this dosing right. We need to establish the best treatment pathway and examine appropriate dosing for people with dementia."

Ballard told Newsweek that he hopes the study will "inform a concerted effort to reduce prescribing, involving everyone involved in dementia treatment and care. We need to explore nonpharmacological alternatives to improve care."

Sally Copley, director of policy campaigns and partnerships at the U.K.-based charity Alzheimer's Society, who was not involved in the study, said the phone calls the organization receives on its helpline demonstrate how important it is to manage pain in dementia patients.

She cautioned the study only involved individuals with dementia and depression, and excluded those with severe pain. "So it's not clear if the results would be the same for people with dementia living in care homes with severe pain," said Copley.

Dr. Laura Phipps of the charity Alzheimer's Research UK, who did not work on the study, said: "Previous studies have also highlighted issues with side effects of other medications used to treat people with dementia, including antipsychotic drugs to treat agitation and aggression.

"With dementia often coming hand in hand with other complex health needs, it's important to explore how dose regimens may need to be adapted for people with dementia, as well as researching nondrug interventions that help to maintain the best quality of life possible while minimizing the susceptibility to harmful side effects."

Anyone worried about the main medication they have been prescribed should contact their doctor, she said.