Glycopyrrolate

Description

Glycopyrrolate is an antagonist of muscarinic acetylcholine receptors (mAChRs; K_is = 0.42, 1.77, 0.52, 0.78, and 1.29 nM for the M₁-M₅ receptors, respectively). It induces relaxation of precontracted isolated human bronchi when used at concentrations of 0.01, 0.1, or 1 μM. Glycopyrrolate reduces post-prandial gastric antral motility in dogs when administered at a dose of 0.01 mg/kg. It inhibits salivation in a rat model of sialorrhea induced by pilocarpine with an ED₅₀ value of 0.74 μg/kg. Formulations containing glycopyrrolate have been used in the treatment of sialorrhea, peptic ulcers, and chronic obstructive pulmonary disease (COPD).

Chemical Properties

White Solid

Uses

Inhaled glycopyrrolate of is used  to treat air flow blockage and prevent worsening of chronic obstructive  pulmonary disease (COPD), including chronic bronchitis and emphysema. COPD is a long-term lung disease that causes bronchospasm (difficulty with breathing).

Uses

Glycopyrrolate inhibits secretion of digestive juices and restores normal stomach function. It is used for treating stomach ulcers, inflamed intestine, and also as a pre-operational drug for inhibiting excess stomach secretion.

Uses

A synthetic, quaternary ammonium anticholinergic. Antispasmodic; preanesthetic medicant.

Definition

ChEBI: A quaternary ammonium salt composed of 3-{[cyclopentyl(hydroxy)phenylacetyl]oxy}-1,1-dimethylpyrrolidin-1-ium and bromide ions in a 1:1 ratio.

General Description

Glycopyrrolate, 3-hydroxy-1,1-dimethylpyrrolidinium bromide -cyclopentylmandelate(Robinul), occurs as a white, crystalline powder that is solublein water or alcohol but practically insoluble in chloroformor ether.
Glycopyrrolate is a typical anticholinergic and possesses,at adequate dosage levels, the atropine-like effectscharacteristic of this class of drugs. It has a spasmolyticeffect on the musculature of the GI tract as well as the genitourinarytract. It diminishes gastric and pancreatic secretionsand the quantity of perspiration and saliva. Its sideeffects are also typically atropine-like (i.e., dryness of themouth, urinary retention, blurred vision, constipation).Glycopyrrolate is a more potent antagonist on M1 than onM2 and M3 receptors. The low affinity of M2 receptorsmay, in part, explain the low incidence of tachycardiaduring use of this drug as an antispasmodic.77 Because ofits quaternary ammonium character, glycopyrrolate rarelycauses CNS disturbances, although in sufficiently highdosage, it can bring about ganglionic and myoneural junctionblock.

Mechanism of action

Glycopyrrolate exhibits onset of action within 1 minute when given intravenously and an elimination half-life of approximately 50 minutes. Glycopyrrolate undergoes urinary excretion and elimination.

Clinical Use

Glycopyrrolate is used as an adjunct in the management of pepticulcer and other GI ailments associated with hyperacidity,hypermotility, and spasm. In common with other anticholinergics,its use does not preclude dietary restrictions or use ofantacids and sedatives if these are indicated.

Side effects

• dry mouth
• blurred vision
• vision problems
• loss of taste
• headache
• nervousness
• confusion
• drowsiness

Safety Profile

Poison by intravenous and intraperitoneal routes. Moderately toxic by ingestion and subcutaneous routes. Experimental reproductive effects. When heated to decomposition it emits very toxic fumes of NOx and Br-. See also BROMIDES.

Synthesis

Glycopyrrolate, 3-[(cyclopentylhydroxyphenylacetyl)oxy]-1,1-dimethylpyrrolidinium bromide (14.1.22), is synthesized from the methyl ester of |á-cyclopentylmandelic acid (14.1.20) by transesterification using 3-hydroxy-1-methylpyrrolidine as an alcohol component, which forms the ester (14.1.21), which is further transformed into a quaternary salt upon reaction with methylbromide, giving glycopyrrolate (14.1.22). The starting methyl ester of |á-cyclopentylmandelic acid (14.1.20) is synthesized by reacting cyclopentylmagnesiumbromide with the methyl ester of phenylglyoxylic acid [17,18].