An anticholinergic agent is a substance that blocks the action of the neurotransmitter acetylcholine at synapses in the central and the peripheral nervous system. These agents inhibit parasympathetic nerve impulses by selectively blocking the binding of the neurotransmitter acetylcholine to its receptor in nerve cells..Anticholinergics are a broad group of medicines that act on the neurotransmitter, acetylcholine. They are also called antispasmodics. By blocking the action of acetylcholine, anticholinergics prevent impulses from the parasympathetic nervous system from reaching smooth muscle and causing contractions, cramps or spasms..On the other hand, there are drugs that have an unintended anticholinergic effect. They include certain antidepressants and antipsychotics which increase or decrease dopamine and serotonin neurotransmitters to alter a person’s mood. In some cases, the drugs can block acetylcholine and lead to anticholinergic side effects..Anticholinergic drugs affect the function of many organs by preventing acetylcholine from binding to its receptors. Anticholinergic drugs decrease the activity of muscles in the gut and reduce production of sweat, saliva, digestive juices, urine, and tears..