Definição e significado de METHACHOLINE

Methacholine

Systematic (IUPAC) name
2-(acetyloxy)-N,N,N-trimethylpropan-1-aminium
Clinical data
AHFS/Drugs.com	International Drug Names
Pregnancy cat.	?
Legal status	?
Identifiers
CAS number	55-92-5 N 62-51-1 (chloride)
ATC code	None
PubChem	CID 6114
DrugBank	DB06709
ChemSpider	5888 Y
UNII	03V657ZD3V Y
KEGG	D04970 Y
ChEBI	CHEBI:50142 Y
ChEMBL	CHEMBL978 N
Chemical data
Formula	C8H18NO2+
Mol. mass	160.234 g/mol
SMILES [Cl-].O=C(OC(C)C[N+](C)(C)C)C
InChI InChI=1S/C8H18NO2.ClH/c1-7(11-8(2)10)6-9(3,4)5;/h7H,6H2,1-5H3;1H/q+1;/p-1 Y Key:JHPHVAVFUYTVCL-UHFFFAOYSA-M Y
N (what is this?)  (verify)

Methacholine (Provocholine) is a synthetic choline ester that acts as a non-selective muscarinic receptor agonist in the parasympathetic nervous system.

  Uses

Methacholine is primarily used to diagnose bronchial hyperreactivity,^[1] 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 cholinomimetic.

  Pharmacology

It is highly active at all of the muscarinic receptors, but has little effect on the nicotinic receptors. Methacholine has a charged quaternary amine structure, rendering it insoluble to lipid cell membranes. 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 resistance to acetylcholinesterases.

Methacholine has a β-methyl group which provides selectivity towards M-type receptors as compared to N-type receptors. The quaternary ammonium group is essential for activity. The ester however makes it susceptible to the enzyme acetylcholine esterase.^[2]

  Contraindications

Use of methacholine, is contraindicated in patients with recent heart attack or stroke, uncontrolled hypertension, known severe airway disease, or an aortic aneurysm. It may be used with caution by nursing or pregnant mothers and patients taking certain medications for myasthenia gravis.^[3]

  References

  External links

• Provocholine.com