A class of drug commonly used to treat everything from chronic obstructive pulmonary disease (COPD) to depression has now been linked to accelerating the loss of mobility in older age. This adds a new dimension to long-term use of anticholinergic drugs, which have already been linked to dementia.
Researchers from the South Australian Health and Medical Research Institute (SAHMRI) and the University of Washington investigated whether long-term anticholinergic medication use could impact the body as much as a growing body of evidence has suggested it effects the brain.
While you may not recognize them by their functional name, anticholinergic drugs are extremely common. Essentially, they dial down the overactivity of the neurotransmitter acetylcholine, which can cause a broad range of health issues. Anticholinergics are used to reduce cold and flu symptoms (diphenhydramine/Benadryl), relieve motion sickness and histamine reactions (promethazine/Phenergan) and relax the bladder to limit frequent urination (oxybutynin/Ditropan). They're also used to relieve muscle stiffness in Parkinson's disease sufferers and even as a common sleep aid.
So why is something that's so widespread and popular – even commonly available as over-the-counter medicine – an issue? Acetylcholine is an important neurotransmitter for thinking, muscle control and memory. By dulling it, those taking an anticholinergic – especially later in life – can experience confusion, drowsiness, dizziness and weakness. Over time, these symptoms can turn into chronic issues with memory and movement.
And this physical movement and weakness aspect is what the researchers were interested in understanding. Earlier studies, many going back to 2015, have formed a growing body of evidence that long-term anticholinergic use could be contributing to accelerated cognitive decline and even triggering dementia. This work is still ongoing.
Now, it seems enduring use of the medication can slow you down physically – effectively aging you faster. In a cohort study of 4,283 people, whose data was collected between 1994 and 2020 as part of the Adult Changes in Thought study, the researchers found "statistically significant associations for gait speed" (walking speed) in people who had taken these drugs in what would be deemed clinically conventional – or more than 1,096 daily doses over 10 years.
The study focused solely on older adults; the average age at baseline for the men and women was 74.3 years, with follow-up assessments at around eight years later. So most of the cohort were in their 80s at the end of the study, and some in their 90s.
The results were adjusted for consecutive years versus that conventional use spread over the decade, as well as comorbidities and other conditions that could impact walking speed and strength.
Advanced modeling also found that people who had taken the drugs more recently (in the previous four years leading up to the study's end date) showed the most significant decline in walking pace. However, there was no significant loss of grip strength, which was also assessed.
Gait speed declined more if people used these drugs a lot – especially in older age. And while decade-long anticholinergic use didn't reveal any significant loss of grip strength, those who met that 1,096 daily-dose threshold in the previous six years were found to have a much higher likelihood of weakened grip as well as slower walking pace.
While the researchers don't advise steering clear of anticholinergics altogether – given that they are very effective in treating the broad range of conditions they do – the research encourages older adults to be mindful of the pros and cons of the drugs, and whether long-term use is ultimately more harmful.
"Anticholinergics are associated with numerous adverse outcomes in older adults; therefore, it is essential for clinicians to avoid their use when possible, prescribe the lowest effective dose, and periodically reevaluate patients to identify de-prescribing opportunities to minimize potential harms," the researchers noted.
The research was published in the journal JAMA Network Open.
Source: University of Washington via Scimex
