Diltiazem

Diltiazem
Clinical data
Pronunciation	/dɪlˈtaɪəzɛm/
Trade names	Cardizem, others
AHFS/Drugs.com	Monograph
MedlinePlus	a684027
License data	US DailyMed: Diltiazem;
Pregnancy; category	AU: C;
Routes of; administration	By mouth, intravenous
Drug class	Nondihydropyridine calcium channel blocker
ATC code	C05AE03 (WHO) C08DB01 (WHO);
Legal status
Legal status	AU: S4 (Prescription only); UK: POM (Prescription only); US: ℞-only; EU: Rx-only; In general: ℞ (Prescription only);
Pharmacokinetic data
Bioavailability	40%
Metabolism	Liver
Elimination half-life	3–4.5 hours
Excretion	Kidney; Bile duct
Identifiers
	IUPAC name cis-(+)-[2-(2-Dimethylaminoethyl)-5-(4-methoxyphenyl)-3-oxo-6-thia-2-azabicyclo[5.4.0]undeca-7,9,11-trien-4-yl]ethanoate;
CAS Number	42399-41-7 ;
PubChem CID	39186;
IUPHAR/BPS	2298;
DrugBank	DB00343 ;
ChemSpider	35850 ;
UNII	EE92BBP03H;
KEGG	D07845 ;
ChEBI	CHEBI:101278 ;
ChEMBL	ChEMBL23 ;
PDB ligand	D6C (PDBe, RCSB PDB);
CompTox Dashboard (EPA)	DTXSID9022940 ;
ECHA InfoCard	100.050.707
Chemical and physical data
Formula	C22H26N2O4S
Molar mass	414.52 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES O=C2N(c3c(S[C@@H](c1ccc(OC)cc1)[C@H]2OC(=O)C)cccc3)CCN(C)C;
	InChI InChI=1S/C22H26N2O4S/c1-15(25)28-20-21(16-9-11-17(27-4)12-10-16)29-19-8-6-5-7-18(19)24(22(20)26)14-13-23(2)3/h5-12,20-21H,13-14H2,1-4H3/t20-,21+/m1/s1 ; Key:HSUGRBWQSSZJOP-RTWAWAEBSA-N ;
	(verify)

Diltiazem, sold under the brand name Cardizem among others, is a nondihydropyridine calcium channel blocker medication used to treat high blood pressure, angina, and certain heart arrhythmias. It may also be used in hyperthyroidism if beta blockers cannot be used. It is taken by mouth or given by injection into a vein. When given by injection, effects typically begin within a few minutes and last a few hours.

Common side effects include swelling, dizziness, headaches, and low blood pressure. Other severe side effects include an overly slow heart beat, heart failure, liver problems, and allergic reactions. Use is not recommended during pregnancy. It is unclear if use when breastfeeding is safe.

Diltiazem works by relaxing the smooth muscle in the walls of arteries, resulting in them opening and allowing blood to flow more easily. Additionally, it acts on the heart to prolong the period until it can beat again. It does this by blocking the entry of calcium into the cells of the heart and blood vessels. It is a class IV antiarrhythmic.

Diltiazem was approved for medical use in the United States in 1982. It is available as a generic medication. In 2022, it was the 100th most commonly prescribed medication in the United States, with more than 6 million prescriptions. An extended release formulation is also available.