Muscarinic antagonist

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

A muscarinic receptor antagonist is an agent that reduces the activity of the muscarinic acetylcholine receptor. Most of them are synthetic, but scopolamine atropine are belladonna alkaloids, and are naturally extracted.

Important^[1] muscarinic agonists include atropine, hyoscine, ipratropium, tropicamide, cyclopentolate and pirenzepine.

Comparison table

Substance	Trade names	Mechanism^[2]	Clinical use^[2]	Adverse effects^[2]
Atropine (D/L-Hyoscyamine)		non-selective antagonism, CNS stimulation	in anaesthesia anticholinesterase poisoning bradycardia antispasmodic in gastrointestinal hypermotility	urinary retention xerostomia blurred vision
Scopolamine (L-Hyoscine)		non-selective antagonism, CNS depression	as atropine motion sickness	as atropine sedation
Ipratropium		non-selective antagonism, without any mucociliary excretion inhibition.	in asthma and bronchitis
Tropicamide		short acting non-selective antagonism, CNS depression	produce mydriasis and cycloplegia in diagnostics	may cause ocular hypertension
Pirenzepine		M1 receptor-selective antagonist inhibits gastric secretion	in peptic ulcer (not much anymore)	(fewer than non-selective ones)
Diphenhydramine	Benadryl
Dimenhydrinate	Dramamine
dicyclomine
flavoxate
oxybutynin
tiotropium	Spiriva
cyclopentolate		short acting non-selective antagonism, CNS depression	produce mydriasis and cycloplegia in diagnostics	may cause ocular hypertension
atropine methonitrate		non-selective antagonism, blocks transmission in ganglia	antispasmodic in gastrointestinal hypermotility
trihexyphenidyl	Artane
tolterodine	Detrusitol
solifenacin	Vesicare
darifenacin	Enablex
benztropine	Cogentin

References

↑ Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone. ISBN 0-443-07145-4. Page 147
↑ ^2.0 ^2.1 ^2.2 Unless else specified in table boxes, then ref is: Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone. ISBN 0-443-07145-4. Page 147

External links

http://cvpharmacology.com/antiarrhy/atropine.htm
Muscarinic+antagonists at the US National Library of Medicine Medical Subject Headings (MeSH)

Template:Drugs for functional gastrointestinal disorders

Template:Mydriatics and cycloplegics Template:Receptor agonists and antagonists

Template:Jb1 Template:WH Template:WS

[Rang147-1] Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone. ISBN 0-443-07145-4. Page 147

[Rang147Unless-2] 2.0 ^2.1 ^2.2 Unless else specified in table boxes, then ref is: Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone. ISBN 0-443-07145-4. Page 147

[1]

[2]

Muscarinic antagonist

Overview

Comparison table

See also

References

External links

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