Anticholinergic effects refer to the side effects caused by medications that block the action of the neurotransmitter acetylcholine. These effects can include dry mouth, blurred vision, constipation, and difficulty urinating. They occur because the medications inhibit the normal functioning of the parasympathetic nervous system, which is responsible for regulating bodily functions like salivation and digestion. Common medications that may cause anticholinergic effects include certain antidepressants, antihistamines, and antipsychotics. While these medications can be effective for treating various conditions, it is important for patients to be aware of potential side effects and discuss any concerns with their healthcare provider.