Muscarinic antagonists


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Muscarinic antagonists

Autonomic medications

Autonomic medications

Cholinergic receptors

Adrenergic receptors

Cholinomimetics: Direct agonists

Cholinomimetics: Indirect agonists (anticholinesterases)

Muscarinic antagonists

Sympathomimetics: Direct agonists

Sympatholytics: Alpha-2 agonists

Adrenergic antagonists: Presynaptic

Adrenergic antagonists: Alpha blockers

Adrenergic antagonists: Beta blockers


Muscarinic antagonists


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Muscarinic antagonists

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External References

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Adverse effects/events

atropine p. 242

Atropine p. 242

antimuscarinic reaction p. 252

for β -blocker overdose p. 329

cholinesterase inhibitor poisoning p. 241

toxicity treatment p. 249


atropine for p. 242


atropine p. 242

Geriatric patients

atropine in p. 242

Glaucoma p. 555

atropine p. 242


atropine as cause p. 242

Urinary retention

atropine p. 242


Content Reviewers

Yifan Xiao, MD


Antonia Syrnioti, MD

Samantha McBundy, MFA, CMI

Sam Gillespie, BSc

Muscarinic antagonists, or antimuscarinic medications, are a class of medications that prevent muscarinic receptors of the parasympathetic nervous system from getting stimulated by acetylcholine.

Okay, first things first, the nervous system is divided into the central nervous system, so the brain and spinal cord; and the peripheral nervous system.

The peripheral nervous system can be divided into the somatic nervous system, which controls voluntary movement of our skeletal muscles; and the autonomic nervous system, which is further divided into the sympathetic and parasympathetic nervous systems, and controls the involuntary movement of the smooth muscles, and the glands of our organs.

Now, the autonomic nervous system is made up of a relay that includes two neurons.

We’ll focus on just the parasympathetic nervous system.

Signals for the parasympathetic nervous system start in the hypothalamus.

These hypothalamic neurons synapse with nuclei in the brainstem or spinal cord, which send out signals to preganglionic neurons that travel to the rest of the body.

Their targets are the parasympathetic ganglion, which consist of many postganglionic neuron cell bodies and are located nearby or directly in the target organs.

The postganglionic neurons extend the rest of the way to the target cell, where they release the neurotransmitter acetylcholine, which is why they are also called cholinergic neurons.


Muscarinic antagonists, also known as antimuscarinic medications, are a class of drugs that block the activation of muscarinic receptors of the parasympathetic nervous system. Examples of muscarinic antagonists include atropine, scopolamine, and ipratropium. These drugs are used to treat a variety of conditions, such as asthma, glaucoma, and urinary incontinence. They can also be used to treat the symptoms of poisoning from organophosphate insecticides.


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  6. "[Atropine. Principles and rules of utilization]" Rev Prat (2001)
  7. "Antimuscarinic drugs" Prof Nurse (2004)

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