Description

Simple

A medication used to treat high blood pressure.

Clinical

A calcium channel blocker used to treat hypertension.

Overview

Felodipine is a long-acting 1,4-dihydropyridine calcium channel blocker (CCB)b. It acts primarily on vascular smooth muscle cells by stabilizing voltage-gated L-type calcium channels in their inactive conformation. By inhibiting the influx of calcium in smooth muscle cells, felodipine prevents calcium-dependent myocyte contraction and vasoconstriction. Felodipine is the most potent CCB in use and is unique in that it exhibits fluorescent activity. In addition to binding to L-type calcium channels, felodipine binds to a number of calcium-binding proteins, exhibits competitive antagonism of the mineralcorticoid receptor, inhibits the activity of calmodulin-dependent cyclic nucleotide phosphodiesterase, and blocks calcium influx through voltage-gated T-type calcium channels. Felodipine is used to treat mild to moderate essential hypertension.

Pharmacology

Indication

For the treatment of mild to moderate essential hypertension.

Pharmacodynamic

Felodipine belongs to the dihydropyridine (DHP) class of calcium channel blockers (CCBs), the most widely used class of CCBs. There are at least five different types of calcium channels in Homo sapiens: L-, N-, P/Q-, R- and T-type. It was widely accepted that CCBs target L-type calcium channels, the... Read more

Mechanism of action

Felodipine decreases arterial smooth muscle contractility and subsequent vasoconstriction by inhibiting the influx of calcium ions through voltage-gated L-type calcium channels. It reversibly competes against nitrendipine and other DHP CCBs for DHP binding sites in vascular smooth muscle and culture... Read more

Absorption

Is completely absorbed from the gastrointestinal tract; however, extensive first-pass metabolism through the portal circulation results in a low systemic availability of 15%. Bioavailability is unaffected by food.

Protein binding

99%, primarily to the albumin fraction.

Volume of distribution

10 L/kg

Clearance

0.8 L/min [Young healthy subjects]

Half life

17.5-31.5 hours in hypertensive patients; 19.1-35.9 hours in elderly hypertensive patients; 8.5-19.7 in healthy volunteers.

Route of elimination

Although higher concentrations of the metabolites are present in the plasma due to decreased urinary excretion, these are inactive. Animal studies have demonstrated that felodipine crosses the blood-brain barrier and the placenta.

Toxicity

Symptoms of overdose include excessive peripheral vasodilation with marked hypotension and possibly bradycardia. Oral rat LD50 is 1050 mg/kg.

Adverse Effects

Contraindications

Information currently not available.

Food Interactions

  • Avoid grapefruit products.
  • Take with or without food. The absorption is unaffected by food.

Interactions

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  • Paracetamol(acetaminophen)
  • Paxil(paroxetine)
  • Pamelor(nortriptyline)
  • Panadol(acetaminophen)
  • Patanol(olopatadine ophthalmic)
  • Pataday(olopatadine ophthalmic)
  • Parnate(tranylcypromine)
  • Pazeo(olopatadine ophthalmic)
(R)-warfarin
The serum concentration of (R)-warfarin can be increased when it is combined with Felodipine.
(S)-Warfarin
The serum concentration of (S)-Warfarin can be increased when it is combined with Felodipine.
1-benzylimidazole
1-benzylimidazole may decrease the antihypertensive activities of Felodipine.
2,4-thiazolidinedione
The risk or severity of hypoglycemia can be increased when Felodipine is combined with 2,4-thiazolidinedione.
2,5-Dimethoxy-4-ethylamphetamine
2,5-Dimethoxy-4-ethylamphetamine may decrease the antihypertensive activities of Felodipine.
2,5-Dimethoxy-4-ethylthioamphetamine
2,5-Dimethoxy-4-ethylthioamphetamine may decrease the antihypertensive activities of Felodipine.
4-Bromo-2,5-dimethoxyamphetamine
4-Bromo-2,5-dimethoxyamphetamine may decrease the antihypertensive activities of Felodipine.
4-hydroxycoumarin
The metabolism of 4-hydroxycoumarin can be decreased when combined with Felodipine.
4-Methoxyamphetamine
The metabolism of 4-Methoxyamphetamine can be decreased when combined with Felodipine.
5-methoxy-N,N-dimethyltryptamine
The metabolism of Felodipine can be decreased when combined with 5-methoxy-N,N-dimethyltryptamine.
6-Deoxyerythronolide B
The metabolism of Felodipine can be decreased when combined with 6-Deoxyerythronolide B.
7-ethyl-10-hydroxycamptothecin
The metabolism of Felodipine can be decreased when combined with 7-ethyl-10-hydroxycamptothecin.
7,8-Dichloro-1,2,3,4-tetrahydroisoquinoline
7,8-Dichloro-1,2,3,4-tetrahydroisoquinoline may increase the hypotensive activities of Felodipine.
9-aminocamptothecin
The metabolism of Felodipine can be decreased when combined with 9-aminocamptothecin.
Abafungin
The therapeutic efficacy of Abafungin can be increased when used in combination with Felodipine.
Abatacept
The metabolism of Felodipine can be increased when combined with Abatacept.
Abediterol
Felodipine may decrease the antihypertensive activities of Abediterol.
Abexinostat
The risk or severity of QTc prolongation can be increased when Felodipine is combined with Abexinostat.
Acalabrutinib
The metabolism of Felodipine can be decreased when combined with Acalabrutinib.
Acarbose
The risk or severity of hypoglycemia can be increased when Felodipine is combined with Acarbose.
1 References
  1. 1 . Dunselman PH, Edgar B: Felodipine clinical pharmacokinetics. Clin Pharmacokinet. 1991 Dec;21(6):418-30.PubMed: 1782737