Pirenzepine

Description

Pirenzepine is available as dihydrochloride monohydrate, soluble in water. Because of its unfavorable balance between weak antisecretory and frequent anticholinergic adverse effects (dry mouth, blurred vision), pirenzepine is considered obsolete .

Chemical properties

solid

Originator

Microsules Bernabo, Microsules Bernabo

The Uses of Pirenzepine

Pirenzepine, is an M1 selective antagonist, that is used in the treatment of peptic ulcers, as it reduces gastric acid secretion and reduces muscle spasm.

The Uses of Pirenzepine

antifungal

Background

An antimuscarinic agent that inhibits gastric secretion at lower doses than are required to affect gastrointestinal motility, salivary, central nervous system, cardiovascular, ocular, and urinary function. It promotes the healing of duodenal ulcers and due to its cytoprotective action is beneficial in the prevention of duodenal ulcer recurrence. It also potentiates the effect of other antiulcer agents such as cimetidine and ranitidine. It is generally well tolerated by patients.

Indications

For the treatment of peptic ulcer, gastric ulcer, and duodenal ulcer.

Definition

ChEBI: Pirenzepine is a pyridobenzodiazepine. It has a role as an anti-ulcer drug, a muscarinic antagonist and an antispasmodic drug.

Manufacturing Process

48.4 g of 5,11-dihydro-6H-pyrido[2,3-b][1,4]benzo-diazepin-6-one were refluxed in 900 ml of absolute dioxane for 15 minutes. Thereafter, over a period of 45 minutes, 28 ml of chloroacetyl chloride and 52 ml of triethylamine were simultaneously added dropwise to the mixture. The mixture was refluxed for eight hours and then vacuum-filtered after having cooled. The filtrate was evaporated in vacuum. The crystalline residue was recrystallized from acetonitrile in the presence of activated charcoal. MP: 212°-213°C (with decomposition). Yield: 85% of theory.
A mixture of 67.5 g of 11-chloroacetyl-5,11-dihydro-6H-pyrido[2,3b][1,4]benzodiazepin-6-one, 183 ml of N-methylpiperazine and 1.37 liters of absolute benzene was refluxed for 18 hours. Thereafter, the crystalline precipitate was vacuum filtered off, dissolved in aqueous 20% hydrochloric acid, the solution was evaporated in vacuum, the crystalline residue wasdissolved in 250 ml of water while heating, the solution was admixed with 150 ml of isopropanol and active charcoal, filtered, and 2.5 liters of isopropanol were added to the filtrate. After cooling, the precipitate was vacuum filtered off, yielding 70% of theory of the 5,11-dihydro-11-[(4'-methyl-1'-piperazinyl)acetyl]-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one dihydrochloride, M.P. 257259°C (decomp.).
The free base of pirenzepine, obtained from the dihydrochloride by making an aqueous solution thereof alkaline with dilute sodium hydroxide and extracting it with chloroform, had MP: 226°-228°C after recrystallization from methanol/ether.

Therapeutic Function

Antiulcer, Antiemetic

Biological Activity

M 1 muscarinic receptor selective antagonist. Inverse agonist activity reported.

Pharmacokinetics

Pirenzepine belongs to a group of medications called antispasmodics/anticholinergics. These medications are used to relieve cramps or spasms of the stomach, intestines, and bladder. Pirenzepine is used to treat duodenal or stomach ulcers or intestine problems. It can be used together with antacids or other medicine in the treatment of peptic ulcer. It may also be used to prevent nausea, vomiting, and motion sickness.

Enzyme inhibitor

This hygroscopic antiulcerative (FWfree-base = 351.41 g/mol; CAS 28797-61- 7) is a gastric acid inhibitor and selective M1 muscarinic receptor antagonist, and the antisecretory properties of pirenzepine on gastric acid and pepsin secretion may be attributed to this antagonistic activity on muscarinic M1 receptors.

Metabolism

Not Available