Muscarinic antagonist

Muscarinic antagonist is a type of drug that blocks the action of the neurotransmitter acetylcholine in the central and the peripheral nervous system. These agents inhibit parasympathetic nerve impulses by selectively blocking the binding of acetylcholine to its receptor in nerve cells. The nerve fibers of the parasympathetic system are responsible for the involuntary movement of smooth muscles present in the gastrointestinal tract, urinary tract, lungs, etc.

Mechanism of Action

Muscarinic antagonists work by binding to muscarinic cholinergic receptors, thereby inhibiting the parasympathetic nervous system. They are competitive inhibitors and are able to bind to the receptor without activating it. This prevents acetylcholine from binding to the receptor and exerting its effect.

Uses

Muscarinic antagonists have a variety of uses in medicine. They are used to treat a variety of conditions, including:

• Gastrointestinal disorders such as peptic ulcers and irritable bowel syndrome
• Respiratory disorders such as chronic obstructive pulmonary disease (COPD) and asthma
• Urinary disorders such as overactive bladder
• Ophthalmic disorders such as mydriasis and cycloplegia

Side Effects

Like all medications, muscarinic antagonists can cause side effects. These may include:

• Dry mouth
• Blurred vision
• Constipation
• Dizziness
• Urinary retention

Examples

Examples of muscarinic antagonists include:

• Atropine
• Scopolamine
• Ipratropium
• Tiotropium
• Oxybutynin

See Also

• Cholinergic antagonist
• Nicotinic antagonist

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  Muscarinic antagonist