The central nervous system and the brain are very sensitive to anticholinergic side effects due to fewer cholinergic neurons or receptors in the brain of older individuals. In addition, the liver and kidney have less ability to break down and excrete medications. Also, drugs can cross more easily into the brain.
Older adults are more sensitive to adverse events associated with anticholinergics, including confusion, dry mouth, blurry vision, constipation, urinary retention, decreased perspiration, and excess sedation. Anticholinergics have also been associated with increased risk of dementia.
These effects may be subtle or dramatic, yet can be overlooked or discounted as a natural consequence of old age. Elderly patients can be particularly sensitive to the anticholinergic action of drugs because of physiological and pathophysiological changes that often accompany the aging process.
Also, people with the following conditions shouldn’t use anticholinergics:
How do anticholinergics affect dementia risk? A. Anticholinergic drugs act by blocking acetylcholine, a chemical involved in nervous system functions. When the drugs block these functions in the brain, it can cause cognitive changes.
Anticholinergic syndrome results from competitive antagonism of acetylcholine at central and peripheral muscarinic receptors. Central inhibition leads to an agitated (hyperactive) delirium – typically including confusion, restlessness and picking at imaginary objects – which characterises this toxidrome.
Typical symptoms include dry mouth, constipation, urinary retention, bowel obstruction, dilated pupils, blurred vision, increased heart rate, and decreased sweating (Table 1).
Common. Anticholinergic effects include dry mouth, constipation, difficulty urinating, and loss of accommodation. α-Antagonism: Orthostatic hypotension and ejaculatory failure may occur. Sedation is probably due to H1 receptor antagonism, and is more common with the phenothiazines.
The orthostatic hypotension common with these agents is caused by antinorepinephrine alpha blockade, and the cardiac conduction problems are caused by inherently toxic effects of the drug on the heart.
The most common CNS side effects of OAB anticholinergic agents are headache, dizziness, somnolence, confusion, and fatigue. However, more serious side effects such as memory impairment, psychotic behavior, insomnia, hallucination, and delirium can also occur [13-17].
Anticholinergic effects: May cause anticholinergic effects (constipation, xerostomia, blurred vision, urinary retention); use with caution in patients with decreased gastrointestinal motility, urinary retention, BPH, xerostomia, or visual problems.
With a suitable prescription, anticholinergics are usually safe, but some people do experience side effects. The potential side effects depend on the individual’s medical history, as well as the dosage and specific type of anticholinergics that they take. Possible side effects include: confusion.
Anticholinergic drugs block the action of acetylcholine. This substance transmits messages in the nervous system. In the brain, acetylcholine is involved in learning and memory. In the rest of the body, it stimulates muscle contractions.
Drugs with anticholinergic properties, such as diuretics and stimulants, are known to cause sleep disturbances, whereas sedatives may lead to daytime drowsiness. These effects of polypharmacy may negatively impact sleep quality and quality of life .
Anticholinergic Cognitive Burden Scale (ACB) developed by Boustani et al.  is based on a systematic literature review of medicines with known anticholinergic activity. The ACB scale included medicines that were likely to have a negative impact on cognition [27,28].
Barone says. (Pro tip: There are lots of helpful meditation apps you can download that include recordings specifically for relaxing your body before sleep.) Dr. Barone also suggests taking 1-3mg of melatonin right around bedtime.