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Muscarinic antagonist



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
trihexyphenidyl Artane
tolterodine Detrusitol
solifenacin Vesicare
darifenacin Enablex
benztropine Cogentin

See also

References

  1. ^ Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone. ISBN 0-443-07145-4.  Page 147
  2. ^ a b c Unless else specified in table boxes, then ref is: Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone. ISBN 0-443-07145-4.  Page 147


 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Muscarinic_antagonist". A list of authors is available in Wikipedia.
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