Wikipedia:WikiProject Chemicals/Chembox validation/VerifiedDataSandbox and Methacholine: Difference between pages

{{Short description|Chemical compound}}

| Watchedfields = changed

| verifiedrevid = 462249464

| tradename = Provocholine

| Drugs.com = {{drugs.com|cdi|methacholine}}

| DailyMedID = Methacholine

| pregnancy_US = N

| pregnancy_category =

| legal_AU = S4

| legal_US = Rx-only

| legal_status =

| routes_of_administration = Respiratory

| ATC_prefix = V04

| ATC_suffix = CX03

| bioavailability =

| protein_bound =

| metabolism =

| elimination_half-life =

| excretion =

| CAS_number_Ref = {{cascite|changed|??}}

| CAS_number = 55-92-5

| CAS_supplemental ={{CAS|62-51-1}} (chloride)

| DrugBank_Ref = {{drugbankcite|correct|drugbank}}

| UNII_Ref = {{fdacite|correct|FDA}}

| KEGG_Ref = {{keggcite|correct|kegg}}

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEMBL = 978

<!--Chemical data-->

| IUPAC_name = 2-(Acetyloxy)-''N'',''N'',''N''-trimethylpropan-1-aminium

| C=8 | H=18 | N=1 | O=2 | charge = +

'''Methacholine''' ([[International Nonproprietary Name|INN]], [[United States Adopted Name|USAN]]) (trade name '''Provocholine'''), also known as '''acetyl-β-methylcholine''', is a synthetic [[choline]] [[ester]] that acts as a non-selective [[muscarinic receptor]] agonist in the [[parasympathetic nervous system]].

==Medical uses==

Methacholine is primarily used to diagnose [[bronchial hyperreactivity]],<ref name="pmid17565027">{{cite journal |vauthors=Birnbaum S, Barreiro TJ |title=Methacholine challenge testing: identifying its diagnostic role, testing, coding, and reimbursement |journal=Chest |volume=131 |issue=6 |pages=1932–5 |date=June 2007 |pmid=17565027 |doi=10.1378/chest.06-1385}}</ref> which is the hallmark of [[asthma]] and also occurs in [[chronic obstructive pulmonary disease]]. This is accomplished through the [[bronchial challenge test]], or methacholine challenge, in which a subject inhales aerosolized methacholine, leading to [[bronchoconstriction]]. Other therapeutic uses are limited by its adverse cardiovascular effects, such as [[bradycardia]] and [[hypotension]], which arise from its function as a [[acetylcholine|cholinomimetic]].

==Pharmacology==

It is highly active at all of the muscarinic receptors, but has little effect on the [[nicotinic receptor]]s. Methacholine has a charged [[quaternary amine]] structure, rendering it insoluble in lipid [[cell membrane]]s. Clinically, this means that it will not cross the [[blood–brain barrier]] and has poor absorption from the [[gastrointestinal tract]]. It is broken down at a relatively slow rate within the body, due to its relative resistance to [[acetylcholinesterase]]s.

The chemical structure of methacholine is identical to [[acetylcholine]] but with a methyl group on the beta carbon (hence being called acetyl-β-methylcholine), this β-methyl group provides selectivity toward [[muscarinic receptor]]s as compared to [[nicotinic receptor]]s. The quaternary ammonium group is essential for activity. The ester makes it susceptible to the enzyme [[acetylcholine esterase]].<ref>{{cite web |title=Medicinal Chemistry of the Peripheral Nervous System – Adrenergics and Cholinergic their Biosynthesis, Metabolism and Structure Activity Relationships |publisher=pharmaxchange.info |url=http://pharmaxchange.info/notes/medicinal_chemistry/adrenergics_cholinergics.html |access-date=2010-10-16 |url-status=dead |archive-url=https://web.archive.org/web/20101104022742/http://pharmaxchange.info/notes/medicinal_chemistry/adrenergics_cholinergics.html |archive-date=2010-11-04}}</ref>{{Unreliable source?|date=August 2018}}

==Contraindications==

Use of methacholine is contraindicated in patients with recent heart attack or stroke, uncontrolled hypertension, known severe airway disease, or aortic aneurysm. It may be used with caution by nursing or pregnant mothers and patients taking certain medications for [[myasthenia gravis]].<ref>{{cite journal |author=Valentin Popa |title=ATS guidelines for methacholine and exercise challenge testing |journal=American Journal of Respiratory and Critical Care Medicine |volume=163 |issue=1 |year=2001 |pages=292–293 |pmid=11208661 |doi=10.1164/ajrccm.163.1.16310b}}</ref>

==References==

{{Reflist}}

==External links==

* {{cite web |url=https://druginfo.nlm.nih.gov/drugportal/name/methacholine |publisher=U.S. National Library of Medicine |work=Drug Information Portal |title=Methacholine}}

* {{cite web |url=https://druginfo.nlm.nih.gov/drugportal/name/methacholine%20chloride |publisher=U.S. National Library of Medicine |work=Drug Information Portal |title=Methacholine chloride}}

{{Muscarinic acetylcholine receptor modulators}}

{{Portal bar|Medicine}}

[[Category:Acetate esters]]

[[Category:Choline esters]]

[[Category:Muscarinic agonists]]

[[Category:Peripherally selective drugs]]

[[Category:Quaternary ammonium compounds]]