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. It has no effects on the brain and spinal cord as it cannot diffuse through the blood–brain barrier.

Pirenzepine has been investigated for use in myopia control.

It promotes the homodimerization or oligomerisation of M₁ receptors.