pharm Chapter 16: Cholinergic Agonists and Antagonists

drugs that affect the parasympathetic nervous system are

(1)   The cholinergic agonists—muscarinic agonists or parasympathomimetics.

(2)   The cholinergic antagonists (blocking agents)—muscarinic antagonists, parasympatholytics, or more commonly called anticholinergics.

The two types of cholinergic receptor

muscarinic receptors, which stimulate smooth muscle and slow the heart rate, and nicotinic receptors, which affect the skeletal muscles.

 

There are two types of cholinergic agonists

direct-acting cholinergic agonists act on receptors to activate a tissue response, and indirect-acting cholinergic agonists inhibit the action of the enzyme cholinesterase (also called acetylcholinesterase).

Drugs that inhibit cholinesterase are called

cholinesterase inhibitors, acetylcholinesterase (AChE) inhibitors, or anticholinesterases.

 

The major responses of cholinergic agonists are to

stimulate bladder and GI tone, miosis, and increase neuromuscular transmission.

Other effects of cholinergic agonists include

decreased heart rate and blood pressure and increased salivary, GI, and bronchial secretions.