**9. Conclusions**

Cholinergic receptors are found throughout the body, but most especially in the CNS. Substances that block these receptors are available both naturally and pharmaceutically. Depending on the location of cholinergic receptors and their subtype, use of anticholinergic medications can result in adverse drug effects in the CNS, the eyes, the exocrine glands, the heart, the GI tract and genitourinary systems and in the skin. Older adults are especially prone to developing adverse

drug events from the use of anticholinergics. Easy to use scales are available to assess the burden of anticholinergic agents in the drug regimen. The Beer's List includes drugs that are potentially inappropriate for use in older adults because of their strong anticholinergic properties. Adverse events associated with the use of anticholinergic agents include drowsiness, sedation, cognitive impairment, confusion, delirium, hallucinations, blurred vision, dizziness, falls/fractures, urinary retention, constipation, tachycardia and xerostomia. Anticholinergic drugs have also been associated with an increase in mortality. These agents are involved with numerous drug–drug interactions adding to the anticholinergic burden. They can antagonize the effects of acetylcholinesterase inhibitors, contribute to the development of GI bleeding in patients on oral, solid forms of potassium supplementation and lead to hyperthermia in patients concomitantly receiving a carbonic anhydrase inhibitor. Anticholinergics should not be used by older adults, especially those with narrow angle glaucoma, obstructive uropathy, myasthenia gravis, obstructive GI tract disease and myocardial ischemia. Avoiding prescribing these agents whenever possible is the first step. If they are utilized, it is important for health care professionals to use the lowest doses possible, closely monitor for signs and symptoms of anticholinergic adverse events and to deprescribe as tolerated.
