Felodipine

3.8

3.65

Breast Feeding; Lactation; Antihypertensive Agents; Calcium Channel Blockers; Vasodilator Agents

FDA approved drugs -> Active ingredient

FDA approved drugs -> Active ingredient

Pharmaceuticals

Warning

H302 (93.2%): Harmful if swallowed [Warning Acute toxicity, oral]

P203, P260, P264, P270, P273, P280, P301+P317, P318, P319, P330, P391, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 59 reports by companies from 11 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

A mild-to-moderate overdose of felodipine can result in hypotension secondary to peripheral vasodilation and reflex tachycardia. However, a severe overdose of felodipine can cause life-threatening profound hypotension and bradycardia. Case fatality due to profound, refractory circulatory collapse overdose has been reported in the literature. The risk of overdose increases in elderly individuals, patients with liver impairment, and concomitant administration of felodipine with beta blockers. Overdose symptoms can include lightheadedness, syncope, altered mental status, and shock secondary to profound hypotension. The insulin release from the pancreas depends on calcium influx through the L-type channels. Felodipine blocks these calcium channels and results in hyperglycemia because of decreased insulin release.

Drug Induced Liver Injury Rank (DILIrank 2.0)

Felodipine

vLess-DILI-concern

3

Adverse reactions

DOI:10.1016/j.drudis.2016.02.015

C08CA02

C - Cardiovascular system

QC - Cardiovascular system

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 major channel in muscle cells that mediates contraction; however, some studies have shown that felodipine also binds to and inhibits T-type calcium channels. T-type calcium channels are most commonly found on neurons, cells with pacemaker activity and on osteocytes. The pharmacologic significance of T-type calcium channel blockade is unknown. Felodipine also binds to calmodulin and inhibits calmodulin-dependent calcium release from the sarcoplasmic reticulum. The effect of this interaction appears to be minor. Another study demonstrated that felodipine attenuates the activity of calmodulin-dependent cyclic nucleotide phosphodiesterase (CaMPDE) by binding to the PDE-1B1 and PDE-1A2 enzyme subunits. CaMPDE is one of the key enzymes involved in cyclic nucleotides and calcium second messenger systems. Felodipine also acts as an antagonist to the mineralcorticoid receptor by competing with aldosterone for binding and blocking aldosterone-induced coactivator recruitment of the mineralcorticoid receptor. Felodipine is able to bind to skeletal and cardiac muscle isoforms of troponin C, one of the key regulatory proteins in muscle contraction. Though felodipine exhibits binding to many endogenous molecules, its vasodilatory effects are still thought to be brought about primarily through inhibition of voltage-gated L-type calcium channels. Similar to other DHP CCBs, felodipine binds directly to inactive calcium channels stabilizing their inactive conformation. Since arterial smooth muscle depolarizations are longer in duration than cardiac muscle depolarizations, inactive channels are more prevalent in smooth muscle cells. Alternative splicing of the alpha-1 subunit of the channel gives felodipine additional arterial selectivity. At therapeutic sub-toxic concentrations, felodipine has little effect on cardiac myocytes and conduction cells.

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 cultured rabbit atrial cells. Calcium ions entering the cell through these channels bind to calmodulin. Calcium-bound calmodulin then binds to and activates myosin light chain kinase (MLCK). Activated MLCK catalyzes the phosphorylation of the regulatory light chain subunit of myosin, a key step in muscle contraction. Signal amplification is achieved by calcium-induced calcium release from the sarcoplasmic reticulum through ryanodine receptors. Inhibition of the initial influx of calcium decreases the contractile activity of arterial smooth muscle cells and results in vasodilation. The vasodilatory effects of felodipine result in an overall decrease in blood pressure. Felodipine may be used to treat mild to moderate essential hypertension.

OL961R6O2C

FELODIPINE

Mechanisms of Action [MoA] - Calcium Channel Antagonists

Established Pharmacologic Class [EPC] - Dihydropyridine Calcium Channel Blocker

Chemical Structure [CS] - Dihydropyridines

Felodipine is a Dihydropyridine Calcium Channel Blocker. The mechanism of action of felodipine is as a Calcium Channel Antagonist.

Agents used for the treatment or prevention of cardiac arrhythmias. They may affect the polarization-repolarization phase of the action potential, its excitability or refractoriness, or impulse conduction or membrane responsiveness within cardiac fibers. Anti-arrhythmia agents are often classed into four main groups according to their mechanism of action: sodium channel blockade, beta-adrenergic blockade, repolarization prolongation, or calcium channel blockade.

Drugs used in the treatment of acute or chronic vascular HYPERTENSION regardless of pharmacological mechanism. Among the antihypertensive agents are DIURETICS; (especially DIURETICS, THIAZIDE); ADRENERGIC BETA-ANTAGONISTS; ADRENERGIC ALPHA-ANTAGONISTS; ANGIOTENSIN-CONVERTING ENZYME INHIBITORS; CALCIUM CHANNEL BLOCKERS; GANGLIONIC BLOCKERS; and VASODILATOR AGENTS.

A class of drugs that act by selective inhibition of calcium influx through cellular membranes.

Drugs used to cause dilation of the blood vessels.

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.

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.

10 L/kg

0.8 L/min [Young healthy subjects]