- Certain anticholinergic agents used to treat depression,
Parkinson's disease or urinary incontinence may be associated with an
increased risk of development of dementia.
- Anticholinergic agents are a class
of drugs that block chemical signals to the brain that control muscle
movements. These agents are often used for conditions such as urinary
incontinence, depression, Parkinson's disease, chronic lung disease (COPD)
use of anticholinergic agents, especially in adults over the age of 45 years
may increase the risk of dementia according to a recent study conducted by the
University of East Anglia, UK. The
findings of the study appear in the British
Aim of Study
- Numerous earlier studies have
reported associations between use of anticholinergic drugs and cognitive
decline and dementia later, but it is not clearly understood whether the
dementia was actually due to the drugs or the underlying condition for
which they were prescribed.
team of scientists led by George Savva at the University of East Anglia,
therefore, undertook to estimate the association
between duration and degree of exposure to
various classes of anticholinergic drugs and subsequent dementia.
‘Drugs with anticholinergic properties should be avoided in older adults and pharmacological and non-pharmacological alternatives should instead be considered.’
Details of Study
- The team studied data from the UK's
Clinical Practice Research Database of 40,770 patients between the ages of
65 to 99 years who were diagnosed with dementia between April 2006 and
- Every case (dementia) patient was matched to up to seven control
patients of the same age and sex, but not suffering from dementia.
- Drugs used to treat them were scored
based on their anticholinergic activity using the Anticholinergic Cognitive Burden (ACB) scale. An ACB score
of 1 meant possible
- anticholinergic activity, while a score
of 2 or 3 meant being definitely anticholinergic.
- Daily doses of each drug were then compared for both
cases and controls with an exposure
period of 4 to 20 years before
a diagnosis of dementia was made.
- During this period, a total of
14,453 (35%) cases and 86,403 (30%) controls were taking at least one anticholinergic drug with an ACB score of 3.
- After ruling out possible
influencing factors, the team found that anti-depressants,
drugs, and drugs to treat
urinary incontinence with definite anticholinergic activity (ACB
score of 3) upped dementia risk up to 20 years after exposure.
- However, an increased risk was not found for drugs with possible
anticholinergic activity (ACB score of 1) or in gastrointestinal or
respiratory drugs having definite anticholinergic activity (ACB score of
- Other anti-depressants
(particularly selective serotonin reuptake inhibitors) with an ACB score
of 1 were linked to dementia, but only closer to the time of prescription,
which may not represent a direct causal link, feel the study team.
Thus, the findings of the
study suggest a possible association between long-term use of anticholinergic agents and
risk of dementia in persons over the age of 45 years.
authors admit that a firm causal link cannot be established and this is mainly
an observational study. Certain
limitations included mis-classification
of dementia in patients and lack of data on the severity of depression
. However, this study was
the largest of its kind till date and accounted for several potential
Takeaway from Study
- The scientists believe that the
association might be "caused by a class specific effect, or by agents
being used for very early symptoms of dementia" and further research
into the effects of specific drug classes is necessary for more clarity.
- However, they feel clinicians
"should continue to be vigilant with respect to the use of
anticholinergic drugs, and should consider the risk of long term cognitive
effects, as well as short term effects, associated with specific drug
classes when performing their risk-benefit analysis."
In an editorial linked to the study, Professor Shelly Gray
at the University of Washington and Professor Joseph Hanlon at the University
of Pittsburgh, say this research "raises important issues about the best
way to summarise anticholinergic burden for future research."
What is Dementia?
refers to a group of symptoms caused by disorders affecting the brain. These
symptoms may include memory loss and difficulties with thinking and
understanding, problem-solving or language, and can become severe enough to
affect a person's ability to perform daily activities. Dementia may also be
associated with changes in mood or behaviour.
Dementia is a progressive condition, meaning the symptoms will gradually get
worse over time as more brain cells are destroyed and eventually die. It is not
a specific disease per se but can be caused by several underlying conditions
such as Alzheimer's disease
, Parkinson disease,
thyroid disease, sleep disorders and certain vitamin deficiencies. A complete
evaluation is therefore necessary to identify the cause and treat as
conclusion, the consensus among the scientists appears to be that anticholinergic
agents are best avoided in older adults.
for most highly anticholinergic drugs, non-pharmacological and pharmacological
alternatives are available and should be considered," they conclude.
- Anticholinergic - (https://en.wikipedia.org/wiki/Anticholinergic#Medical_uses)