Otenzepad

Otenzepad is a competitive muscarinic receptor antagonist that is relatively selective at the M2 receptor. It was investigated as a treatment for arrhythmia and bradycardia due to its cardioselectivity but research ceased after stage III clinical trials. The drug was originally developed by the German pharmaceutical company, Boehringer Ingelheim Pharma KG.^[1]

Otenzepad

Structure of Otenzepad
Clinical data
Routes of administration	oral
Pharmacokinetic data
Bioavailability	45% (oral)[1]
Elimination half-life	2.5h
Identifiers
IUPAC name 11-[2-[2-(diethylaminomethyl)piperidin-1-yl]acetyl]-5H-pyrido[2,3-b][1,4]benzodiazepin-6-one
CAS Number	102394-31-0 Y
PubChem CID	107867
IUPHAR/BPS	309
ChemSpider	97004
UNII	OM7J0XAL0S
ChEBI	CHEBI:111174
ChEMBL	ChEMBL17045
CompTox Dashboard (EPA)	DTXSID0045674
ECHA InfoCard	100.220.541
Chemical and physical data
Formula	C24H31N5O2
Molar mass	421.545 g·mol−1
3D model (JSmol)	Interactive image
SMILES CCN(CC)CC1CCCCN1CC(=O)N2C3=CC=CC=C3C(=O)NC4=C2N=CC=C4
InChI InChI=1S/C24H31N5O2/c1-3-27(4-2)16-18-10-7-8-15-28(18)17-22(30)29-21-13-6-5-11-19(21)24(31)26-20-12-9-14-25-23(20)29/h5-6,9,11-14,18H,3-4,7-8,10,15-17H2,1-2H3,(H,26,31) Key:UBRKDAVQCKZSPO-UHFFFAOYSA-N

Pharmacodynamics

The (+)-enantiomer has 8 times greater potency at the M2 receptor than the (-)-enantiomer.^[1]

Potency of Otenzepad at muscarinic receptor isoforms^[1]

mAChR isoform	Dissociation constant (Ki)
M1	537.0 - 1300nM[1][2]
M2	81.0 - 186nM[1][2]
M3	838 - 2089.0nM[2][1]
M4	407.0 - 1800nM[1][2]
M5	2800nM[2]

See also

• Muscarinic antagonist
• Antiarrhythmic agent