Cholinergic agents

Cholinergic agents are a category of drugs and other substances that produce, alter, or mimic the effects of the neurotransmitter acetylcholine within the body. These agents are important in a wide range of bodily functions, including muscle contraction, heart rate, digestion, and memory.

Mechanism of action

Cholinergic agents work by interacting with cholinergic receptors on the surface of cells. These receptors are activated by the neurotransmitter acetylcholine, which is released by nerve cells in response to certain signals. Cholinergic agents can either mimic the effects of acetylcholine (known as agonists) or block its effects (known as antagonists).

Types of cholinergic agents

There are two main types of cholinergic agents: direct-acting and indirect-acting.

Direct-acting cholinergic agents bind directly to cholinergic receptors and activate them, mimicking the effects of acetylcholine. Examples of direct-acting agents include carbachol, bethanechol, and pilocarpine.

Indirect-acting cholinergic agents work by inhibiting the enzyme acetylcholinesterase, which breaks down acetylcholine in the synaptic cleft. By inhibiting this enzyme, these agents increase the amount of acetylcholine available to bind to and activate cholinergic receptors. Examples of indirect-acting agents include physostigmine, neostigmine, and donepezil.

Clinical uses

Cholinergic agents have a wide range of clinical uses, due to the widespread distribution of cholinergic receptors in the body. They are used in the treatment of conditions such as glaucoma, myasthenia gravis, Alzheimer's disease, and certain types of urinary incontinence.

Side effects

The side effects of cholinergic agents are generally related to overstimulation of the parasympathetic nervous system. These can include bradycardia, hypotension, bronchoconstriction, increased salivation and sweating, nausea, and diarrhea.

See also

• Anticholinergic
• Parasympathomimetic drug
• Neurotransmitter