GPs have been urged to review the use of anticholinergic medications in their elderly patients, particularly those with dementia, after researchers found their use was associated with declines in both physical and cognitive function.
Their systematic review published in Age and Ageing found these declines in functioning were related to the number of anticholinergic drugs and length of time taken.
The researchers said patients could be at increased risk of becoming unable to carry out normal daily activities like feeding themselves, washing and getting dressed as a result.
The team, led by Dr Chris Fox, honorary consultant psychogeriatrician at the University of East Anglia Norwich medical school, looked at 46 studies from around the world, including a total of 60,944 patients who had taken anti-cholinergic medications for up to 10 years.
Of these, five out of eight studies that considered physical function showed anticholinergic drugs were associated with significantly reduced scores on measures of activities of daily living and increased use of mobility aids. Two of the studies also showed a correlation between the increase in anticholinergic burden and the reduction in ability to carry out daily activities, while another found a cumulative effect of anticholinergics over time on reduced functional impairment.
In addition, 23 out of a total of 33 studies that looked at cognitive effects found anticholinergics were associated with an increased risk of incident cognitive impairment or reductions in measures of cognitive function.
The researchers concluded: ‘This systematic review provides strong evidence for the adverse effect of increased anticholinergic load on cognition. The results also show consistent evidence that medicines with anticholinergic properties may be associated with reduced physical function.’
The team said further research is still needed to confirm whether the drugs are directly to blame and whether any particular types of anticholinergic are more harmful than others.
But Dr Fox told Pulse GPs should in the meantime review the use of drugs with anticholinergic effects in their elderly patients with dementia, and those taking five or more medications, and consider switching them onto alternative drugs where possible.
Dr Fox said: ‘Once you start to get to five medications, you start to get increased risks of interactions and side effects, so these patients should be targeted to see if they’ve got a high anticholinergic score and then you should consider alternatives.
‘There are some drugs used for bladder control drugs that affect the cholinergic system, there are other newer ones that don’t – so obviously switching between those is one option.
‘Also some cardiac medications have anticholinergic effect – there are alternatives without anti-cholinergic side effects that can be found relatively easily.’
Professor Tony Avery, professor of primary care at Nottingham University and a GP in the city, agreed that until further evidence comes available GPs should review the use of these drugs carefully and consider alternatives – but added that this could be challenging in practice.
Professor Avery said: ‘This is a big challenge for GPs because we use these drugs to manage a wide variety of conditions that can be very troublesome for patients. One example is the use of anticholinergic drugs in older people with urinary incontinence.
‘GPs have to balance the short-term benefits of improved continence with possible long-term effects on cognitive function. Involving patients in the decision making may be helpful, and if patients are taking more than one drug with anticholinergic side effects it might be sensible to come to a joint decision on which (if any) is the highest priority for longer-term use.’