A critical study has established between the long-term usage of certain anticholinergic drugs to a higher risk of dementia later on in life and this particular research is believed to be the largest and the most detailed investigation till date into long-term anticholinergic use and risk of dementia.
Anticholinergic are drugs that work by blocking a chemical messenger or a neurotransmitter called acetylcholine that carries brain signals for controlling muscles.
These drugs are used in the treatment of a variety of conditions from Parkinson’s disease and loss of bladder to asthma, chronic obstructive pulmonary disease and depression.
Anticholinergics that are used for depression, for e.g. amitriptyline, dosulepin and paroxetine have been linked previously to a higher risk of dementia even when they were used before 20 years.
A few studies have even suggested that use of any kind of anticholinergic is connected to a high risk of dementia.
Long-term use of certain anticholinergics
A new study was conducted by the University of East Anglia in the United Kingdom and the results have now been published in the BMJ, found that the long-term usages of only certain types of anticholinergics are associated with higher dementia risk.
It confirms the link to long-term use of anticholinergics for depression, and also for Parkinson’s disease (such as procyclidine) and loss of bladder control (for example, oxybutynin, solifenacin, and tolterodine).
Nevertheless, this particular study was not successful in finding any link between increased risk of dementia and other anticholinergic drugs like antihistamines and medications that are used for abdominal cramps.
In order to carry out their research, the scientists used data from the Clinical Practice Research Database which had anonymous records of more than 11 million people across UK.
Anticholinergic Cognitive Burden
That dataset that was made use of in the study had details of 40,770 patients who suffered from dementia in the age group 65-99, diagnosed in between the year2006-2015. Each of them was compared with 7 individuals who did not have dementia but who belonged to the same sex and were of the same age group.
A system called the Anticholinergic Cognitive Burden scale was used to determine the effect of such drugs on the patients.
An ACB score of 1 meant that a drug was “possibly anticholinergic,” but a score of 2 or 3 meant that it was “definitely anticholinergic.” In totality, more than 27 million prescriptions were analyzed in the process.
The records and the matched controls of the patients were reviewed in order to count all prescriptions and doses for drugs with an ACB score of 1-3 during the period covering 4-20 years before making the dementia diagnosis.
It was discovered that 35% of the dementia patients and 30% of the control patients were prescribed a minimum of one drug with a score of 3 on the ACB scale during the period. Further research was carried out in order to ascertain the effect of factors that might influence the results.
Further analysis found that drugs with an ACB score of 3 that was prescribed for depression, Parkinson’s disease and loss of bladder control were connected to a higher link of dementia even after 20 years of the exposure.
Clinicians Must Keep Vigil
The researchers did point out about the shortcomings of their pattern of study and have clearly mentioned that they cannot say if anticholinergics are directly responsible for dementia or not.
A possibility, according to them is that people taking drugs are already in the very early stages of dementia.
But, since the link was there even when exposure took place 15-20 years before dementia was diagnosed, the authors proclaim that “reverse causation or confounding with early dementia symptoms are less likely explanations.”
Clinicians have been advised to be vigilant at all times when it comes to the use of anticholinergic drugs and they have also been asked to take into account the possible long term and short term effects while comparing the risks versus benefits.
Importance of Research
More than 50 million people across the globe are affected by dementia and each year 10 million more are diagnosed with the same. It is painful for the person when he finds out that he is suffering from a disease that will rob away their ability to think, remember, hold a conversation and live independently. “People are skeptical of scientists and doctors truly want to cure the disease rather than simply manage It and make money”, says Alan Goodall – moderator of a popular pharmacy forum.
“This research is really important,” explains study leader Dr. George Savva, who works in the School of Health Sciences at UEA, “because there are an estimated 350 million people affected globally by depression, and bladder conditions requiring treatment are estimated to affect over 13 percent of men and 30 percent of women in the U.K. and [United States].”
“Many of the treatment options for these conditions,” he continues, “involve medication with anticholinergic effects.”
As per Dr. Savva, “Developing strategies to prevent dementia, therefore, becomes a global priority.”
In an editorial article associated with the study, Prof. Shelly Gray from the University of Washington in Seattle and Prof. Joseph Hanlon from the University of Pittsburgh in Pennsylvania mentioned that authors did a commendable job of addressing the problem of the best manner to “summarize anticholinergic burden for future research.”
They also second that in the meantime, as recommended by guidelines, anticholinergics, in general, should be avoided in order adults.