Felodipine

Felodipine

Systematic (IUPAC) name
(RS)-3-ethyl 5-methyl 4-(2,3-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate
Clinical data
Trade names	Plendil
AHFS/Drugs.com	monograph
MedlinePlus	a692016
Pregnancy category	US: C (Risk not ruled out)
Legal status	℞ (Prescription only)
Routes of administration	Oral
Pharmacokinetic data
Bioavailability	15%
Metabolism	Hepatic
Onset of action	2.5–5 hours
Biological half-life	25 hours
Excretion	Renal
Identifiers
CAS Number	72509-76-3 Y
ATC code	C08CA02 (WHO)
PubChem	CID: 3333
IUPHAR/BPS	4190
DrugBank	DB01023 Y
ChemSpider	3216 Y
UNII	OL961R6O2C Y
KEGG	D00319 Y
ChEBI	CHEBI:585948 Y
ChEMBL	CHEMBL1480 Y
Chemical data
Formula	C18H19Cl2NO4
Molecular mass	384.259 g/mol
SMILES O=C(OCC)\C1=C(\N/C(=C(/C(=O)OC)C1c2cccc(Cl)c2Cl)C)C
InChI InChI=1S/C18H19Cl2NO4/c1-5-25-18(23)14-10(3)21-9(2)13(17(22)24-4)15(14)11-7-6-8-12(19)16(11)20/h6-8,15,21H,5H2,1-4H3 Y Key:RZTAMFZIAATZDJ-UHFFFAOYSA-N Y
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Felodipine is a calcium channel blocker (calcium antagonist), a drug used to control hypertension (high blood pressure). It is marketed under the brand name Plendil by AstraZeneca and Renedil by Sanofi-Aventis. The formulation patent for the substance expired in 2007.

AstraZeneca dropped Plendil from its support and AZ&Me free Rx access program in October 2008.

Interactions

Studies dating back to 1989 have suggested that felodipine in combination with grapefruit juice can cause toxic effects. Oral administration of felodipine is first metabolized in the gastrointestinal tract and liver by the enzyme CYP3A4. Grapefruit juice contains bergamottin which is found to have an inhibiting effect over this enzyme and as a result the bioavailability of the drug increases, raising the risk for abnormal side effects.

Contraindications and cautions

Contraindicated with allergy to felodipine or other calcium channel blockers, sick sinus syndrome, AV heart block (second and third degree), lactation. Use cautiously with pregnancy, impaired hepatic function.