Pirenzepine

Pirenzepine
Clinical data
Trade names	Gastrozepin
AHFS/Drugs.com	International Drug Names
ATC code	A02BX03 (WHO) ;
Identifiers
	IUPAC name 11-[(4-methylpiperazin-1-yl)acetyl]-5,11-dihydro-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one;
CAS Number	28797-61-7 ;
PubChem CID	4848;
IUPHAR/BPS	328;
DrugBank	DB00670 ;
ChemSpider	4682 ;
UNII	3G0285N20N;
KEGG	D08389 ;
ChEBI	CHEBI:8247 ;
ChEMBL	ChEMBL9967 ;
CompTox Dashboard (EPA)	DTXSID7023487 ;
ECHA InfoCard	100.044.739
Chemical and physical data
Formula	C19H21N5O2
Molar mass	351.410 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES O=C3c1ccccc1N(C(=O)CN2CCN(C)CC2)c4ncccc4N3;
	InChI InChI=1S/C19H21N5O2/c1-22-9-11-23(12-10-22)13-17(25)24-16-7-3-2-5-14(16)19(26)21-15-6-4-8-20-18(15)24/h2-8H,9-13H2,1H3,(H,21,26) ; Key:RMHMFHUVIITRHF-UHFFFAOYSA-N ;
	(verify)

Pirenzepine (Gastrozepin), an M₁ selective antagonist, is used in the treatment of peptic ulcers, as it reduces gastric acid secretion and reduces muscle spasm. It is in a class of drugs known as muscarinic receptor antagonists; acetylcholine is the neurotransmitter of the parasympathetic nervous system which initiates the rest-and-digest state (as opposed to fight-or-flight), resulting in an increase in gastric motility and digestion; whereas pirenzepine would inhibit these actions and cause decreased gastric motility leading to delayed gastric emptying and constipation.^[1] It has no effects on the brain and spinal cord as it cannot diffuse through the blood–brain barrier.