Methacholine

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 YesY
62-51-1 (chloride)
ATC code None
PubChem CID 6114
DrugBank DB06709
ChemSpider 5888 YesY
UNII 03V657ZD3V N
KEGG D04970 N
ChEBI CHEBI:50142 N
ChEMBL CHEMBL978 N
Chemical data
Formula C8H18NO2+
Mol. mass 160.234 g/mol
SMILES eMolecules & PubChem
 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.

Contents

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

  1. ^ Birnbaum S, Barreiro TJ (June 2007). "Methacholine challenge testing: identifying its diagnostic role, testing, coding, and reimbursement". Chest 131 (6): 1932–5. doi:10.1378/chest.06-1385. PMID 17565027. http://www.chestjournal.org/cgi/pmidlookup?view=long&pmid=17565027. 
  2. ^ Medicinal Chemistry of Adrenergics and Cholinergics
  3. ^ http://ajrccm.atsjournals.org/cgi/content/full/161/1/309

External links


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Look at other dictionaries:

  • Methacholine challenge test — A methacholine challenge test is a medical test used to assist in the diagnosis of asthma. The patient breathes in nebulized methacholine. This provokes narrowing of the airways (bronchoconstriction). This is detected when the patient performs… …   Wikipedia

  • methacholine chloride — A derivative of acetylcholine; a parasympatomimetic agent used as a bronchoconstrictor in testing for bronchial hyperreactivity. * * * [USP] the chloride salt of methacholine, used as a cholinergic, especially in the treatment of Raynaud disease …   Medical dictionary

  • methacholine challenge — a type of bronchial challenge or inhalational challenge used as a test for airway reactivity or atopic asthma; aerosolized methacholine is applied to the airways and the patient is assessed for responsiveness or hyperresponsiveness …   Medical dictionary

  • methacholine — noun A synthetic choline ester that alters the activity of muscarinic receptors in certain neurons …   Wiktionary

  • methacholine — metha·cho·line .meth ə kō .lēn n a parasympathomimetic drug administered in the form of its crystalline chloride C8H18ClNO2 esp. to diagnose hypersensitivity of the bronchial air passages (as in asthma) see MECHOLYL, provocholine * * *… …   Medical dictionary

  • methacholine — metha·choline …   English syllables

  • methacholine — noun parasympathomimetic drug (trademark Mecholyl) that stimulates secretions and smooth muscle activity • Syn: ↑Mecholyl • Usage Domain: ↑trademark (for: ↑Mecholyl) • Hypernyms: ↑medicine, ↑ …   Useful english dictionary

  • MICR — methacholine inhalation challenge response …   Medical dictionary

  • MICR — • methacholine inhalation challenge response …   Dictionary of medical acronyms & abbreviations

  • Metacholintest — Der Methacholintest (Methacholin Provokationstest, engl.: Methacholine Challenge Test ) ist ein unspezifischer, inhalativer Provokationstest, der in der Pneumologie und Allergologie zur Messung von bronchialer Obstruktion und Hyperreaktivität… …   Deutsch Wikipedia

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