What are the side effects of anticholinergic medications?

Anticholinergics are drugs that block the action of acetylcholine, a neurotransmitter, or a chemical messenger, that carries parasympathetic nerve impulses. They reduce spasms of smooth muscles (for example, muscles in the bladder). Side effects include dry mouth, blurry vision, constipation, trouble urinating, drowsiness, memory problems, and confusion.