L-type calcium channel

In CLL cells, ephacrynic acid (50 μM; 24 hours) suppresses Wnt/β-catenin signaling [1]. With an IC50 of 8.56 μM, ethanolic acid (1-100 μM; 48 hours) is cytotoxic to CLL cells [1]. The eye's aqueous humor rises in response to diuretic acid (0.01-0.25 mmol/L; 30 minutes), and the rate of water outflow increases from 28% to 105% [2]. Diuric acid has anti-inflammatory properties and can decrease the activation of NF-κB staining in RAW264.7 cells when used in LPS (100 ng/mL) at 10-100 μM for 30 minutes [3]. MCF-7 spots exposed to radiation are improved by ethanolacrynic acid (20 μM/mL; 2 hours). High-K+ (80 mmol/L) and acetylcholine (acetylcholine, ACh, 100 μmol/L) are inhibited by ethanolic acid (100 μmol/L; 62.5-250 minutes). In mice, the EC50 resulting from contraction of the tracheal ring was 40.28 µmol/L and 56.22 µmol/L, respectively[8]. The intracellular Ca2+ concentrations caused by high K+ and ACh were decreased from 0.40 to 0.16 and from 0.50 to 0.39, respectively, by ethacrynic acid (100 µmol/L; 500-2500 seconds) [8]. Real-time polymerase chain reaction

Ethacrynic Acid (450 μg/mouse; oral form; once daily for 60 days) suppresses tumor growth in mice [5].

RT-PCR[1]
Cell Types: Chronic lymphocytic leukemia (CLL)
Tested Concentrations: 1 μM, 10 μM, 100 μM
Incubation Duration: 16 h
Experimental Results: Inhibition of the expression of LEF-1, Cyclin D1 and Fibronectin was concentration-dependent. (LEF-1, Cyclin D1, and Fibronectin are established target genes of the Wnt/b-catenin pathway).

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Western Blot Analysis [3]
Cell Types: RAW 264.7
Tested Concentrations: 10 μM, 20 μM, 50 μM, 100 μM; before LPS treatment (100 ng/mL; 1 h)
Incubation Duration: 30 min
Experimental Results: Inhibition of iNOS mRNA expression. Inhibits the degradation of IκBα and IκBβ.

Animal/Disease Models: Myeloma Balb/c mouse model [5]
Doses: 450 μg/mouse: po (oral gavage); one time/day for 60 days. balb/c (Bagg ALBino) mouse were injected subcutaneously (sc) (sc) with 5 × 105 MPC11 myeloma cells.
Experimental Results: Dramatically inhibited tumor growth.

Absorption, Distribution and Excretion
Ethacrylic acid has a rapid onset of action, typically within 30 minutes after oral administration and within 5 minutes after intravenous injection. Regardless of the route of administration, less than 35% of ethacrylic acid is excreted in the urine of rats and dogs, while more than 50% is excreted in the feces, suggesting that the drug is primarily excreted via the liver. Renal excretion accounts for 67%, bile/fecal excretion for 33%, and 20% is excreted unchanged. (Data from table) Ethacrylic acid is rapidly absorbed from the gastrointestinal tract. After oral administration, diuresis occurs within 30 minutes and reaches its peak at approximately 2 hours. The duration of action after oral administration is typically 6–8 hours, but can be as long as 12 hours. Following intravenous administration of sodium ethacrynic acid, diuresis typically begins within 5 minutes, reaches its maximum within 15–30 minutes, and lasts for approximately 2 hours. In animals, large amounts of ethacrylic acid accumulate only in the liver. The drug does not enter the cerebrospinal fluid. It is currently unclear whether ethacrylic acid can cross the placenta or be distributed into breast milk. Following intravenous administration of sodium ethacrylic acid, approximately 30-65% of the drug is secreted via the proximal renal tubules and excreted in the urine; approximately 35-40% is excreted in the bile, partly as cysteine conjugates. In dogs, approximately 30-40% of the drug excreted in the urine is unchanged, 20-30% is as cysteine conjugates, and 33-40% is an unstable, unknown compound. The urinary excretion rate of ethacrylic acid increases with increasing urine pH and can be decreased by probenecid. Metabolism/Metabolites: Hepatic metabolism. In rats, following intravenous administration of (5 or 50 mg/kg) 14C-ethacrylic acid, 60-70% is excreted into the bile within 4 hours; of this, <25% is ethacrylic acid, and the remainder is biotransformation products. Two major metabolites were identified in bile: glutathione adduct (ethacrynic acid-GSH) and ethacrynic acid-mercaptourate. Approximately 40% of the bile was excreted as ethacrynic acid-GSH at both doses. Ethacrynic acid-mercaptourate accounted for 18% and 30% of bile excretion in the low-dose and high-dose groups, respectively. Following intravenous administration of 5 mg/kg ethacrynic acid to dogs, 25%, 11%, and 9% of the dose were excreted as ethacrynic acid-mercaptourate, ethacrynic acid-cysteine, and ethacrynic acid-glutathione, respectively. Animal studies suggest that ethacrynic acid is metabolized into a cysteine conjugate (which may contribute to the drug's pharmacological action) and an unstable, unidentified compound.

Effects During Pregnancy and Lactation
◉ Overview of Use During Lactation
Since there is currently no information regarding the use of ethacrynic acid during lactation, and potent diuresis may reduce milk production, alternative medications are recommended, especially when breastfeeding newborns or premature infants. Low doses of ethacrynic acid may not suppress lactation.
◉ Effects on Breastfed Infants
As of the revision date, no relevant published information was found.
◉ Effects on Lactation and Breast Milk
Ethacrynic acid has been reported to be successfully used to suppress lactation in six postpartum women who did not wish to breastfeed, and to reduce the intensity of lactation in another woman. No additional effects of diuretics on other effective lactation suppression measures have been studied. There are currently no data on the effects of loop diuretics on established sustained lactation.

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Protein Binding
>98%Interactions
Polypotent diuretics may interact adversely with other drugs. Ethacrynic acid and furosemide have high binding rates to plasma albumin, potentially competing with drugs such as warfarin and clofibrate for protein binding sites. Caution should be exercised when using any cephalosporin in combination with Ethacrynic acid. The ototoxic interactions between aminoglycoside antibiotics (streptomycin, kanamycin, etc.) and loop diuretics (such as Ethacrynic acid) are well-documented. These interactions can lead to extensive damage to cochlear hair cells. When purpuricin, capreomycin, and polymyxin B are used in combination with Ethacrynic acid, cochlear hair cell damage has been found to be similar in extent to that caused by the combination of aminoglycoside antibiotics and Ethacrynic acid. In mice, intramuscular injection of neomycin (100 mg/kg body weight) 60 minutes before Ethacrynic acid treatment increased Ethacrynic acid accumulation in the cochlear structures by 3-5 times. This suggests that neomycin may disrupt the hemolabyrinth or tissue permeability barrier, thereby promoting the penetration of another drug into the inner ear.
A patient who developed sudden deafness and ataxia after taking furosemide and ethacrynic acid had their temporal bone examined using light and electron microscopy. The results showed no loss of hair cells or supporting cells. Some hair cells in the vestibular neuroepithelium and organ of Corti, particularly in the basal gyrus, stained more intensely and exhibited a more granular appearance than normal. Membrane vortices were also commonly observed within the mitochondria of these cells. Endoplasmic reticulum dilatation was observed in some spiral ganglion cells. Major cytological changes were seen in the stria vascularis of the cochlea and the dark cell region of the vestibular system. Significantly widened intercellular spaces were observed, consistent with biochemical observations that loop diuretics primarily interfere with the enzyme system responsible for fluid transport in the inner ear.
For more complete data on interactions with ethacrynic acid (11 types), please visit the HSDB record page.

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Non-human toxicity values
Mouse intravenous LD50: 175 mg/kg (sodium ethacrylate)
Mouse oral LD50: 627 mg/kg
Rat oral LD50: 1 g/kg
Rat intraperitoneal LD50: 43 mg/kg

[1]. Ethacrynic acid exhibits selective toxicity to chronic lymphocytic leukemia cells by inhibition of the Wnt/beta-catenin pathway. PLoS One. 2009 Dec 14;4(12):e8294.

[2]. Ethacrynic acid increases facility of outflow in the human eye in vitro. Arch Ophthalmol. 1992 Jan;110(1):106-9.

[3]. Ethacrynic acid inhibits multiple steps in the NF-kappaB signaling pathway. Shock. 2005 Jan;23(1):45-53.

[4]. Ethacrynic acid: a novel radiation enhancer in human carcinoma cells. Int J Radiat Oncol Biol Phys. 1996 Jan 15;34(2):375-80.

[5]. In vivo efficacy of the diuretic agent ethacrynic acid against multiple myeloma. Leuk Res. 2012 May;36(5):598-600.

[6]. Metabolism of Strained Rings: Glutathione S-transferase-Catalyzed Formation of a Glutathione-Conjugated Spiro-azetidine without Prior Bioactivation. Drug Metab Dispos. 2019 Nov;47(11):1247-1256.

[7]. Ethacrynic acid decreases expression of proinflammatory intestinal wall cytokines and ameliorates gastrointestinal stasis in murine postoperative ileus. Clinics (Sao Paulo). 2018 Oct 18;73:e332.

[8]. [Ethacrynic acid inhibits airway smooth muscle contraction in mice]. Sheng Li Xue Bao. 2019 Dec 25;71(6):863-873. Chinese. PMID: 31879742.

[9]. Ethacrynic Acid Inhibits Sphingosylphosphorylcholine-Induced Keratin 8 Phosphorylation and Reorganization via Transglutaminase-2 Inhibition. Biomol Ther (Seoul). 2013 Sep 30;21(5):338-42.

Ethacrynic acid is a white solid. (NTP, 1992)
Ethacrynic acid is an aromatic ether, a derivative of phenoxyacetic acid, with chlorine atoms substituted at positions 2 and 3 of the benzene ring and a 2-methylenebutyryl group substituted at position 4. It is a loop diuretic used to treat hypertension caused by conditions such as congestive heart failure, liver failure, and kidney failure. It is also an inhibitor of glutathione S-transferase (EC 2.5.1.18). It has the effects of ion transport inhibitor, glutathione S-transferase (EC 2.5.1.18) inhibitor, and loop diuretic. It is an aromatic ether, monocarboxylic acid, aromatic ketone, and dichlorobenzene. It is functionally related to acetic acid.
This compound primarily inhibits the ascending limb of the loop of Henle, but also inhibits the cotransport of sodium, potassium, and chloride in the proximal and distal tubules. This pharmacological action leads to increased excretion of these ions, increased urine volume, and decreased extracellular fluid. This compound is classified as a loop diuretic or a highly potent diuretic. Ethacrynic acid is a loop diuretic. Its physiological effect is achieved by increasing the diuretic effect of the loop of Henle. Ethacrynic acid is an unsaturated ketone derivative of aryloxyacetic acid, without sulfonamide substituents, and belongs to the loop diuretic class. Ethacrynic acid is extensively bound to plasma proteins; both ethacrynic acid and its metabolites are excreted unchanged in bile and urine. Ethacrynic acid primarily inhibits the cotransport of sodium, potassium, and chloride in the ascending limb of the loop of Henle, but also inhibits cotransport in the proximal and distal tubules. This pharmacological action leads to increased excretion of these ions, increased urine volume, and decreased extracellular fluid. This compound is classified as a loop diuretic or a highly potent diuretic. Indications: Used to treat hypertension and edema caused by conditions such as congestive heart failure, liver failure, and kidney failure.
FDA Label

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Mechanism of Action
Ethacrylic acid primarily inhibits the cotransport of sodium, potassium, and chloride in the ascending limb of the loop of Henle, but also inhibits cotransport in the proximal and distal tubules. This pharmacological action leads to the excretion of these ions, increasing urine volume and reducing extracellular fluid. Diuretics initially lower blood pressure by reducing plasma and extracellular fluid volume; cardiac output also decreases, which explains their hypotensive effect. Eventually, cardiac output returns to normal, and peripheral resistance also decreases. Its mechanism of action does not involve carbonic anhydrase inhibition.
Optimal diuretic activity depends on at least two structural requirements: (1) a methylene group and an adjacent ketone group capable of reacting with the thiol radical of the presumed receptor, and (2) a substituent on the aromatic ring.
In vitro studies have shown that ethacrylic acid inhibits the active transport of chloride ions in the lumen of the ascending limb of the loop of Henle, thereby reducing the reabsorption of sodium and chloride at this site. Because even low concentrations of ethacrylic acid can produce this inhibitory effect in the presence of cysteine, it has been proposed that the ethacrylic acid-cysteine metabolite is the most active form of the drug. This drug increases potassium excretion in the distal renal tubules. Ethacrylic acid does not inhibit carbonic anhydrase, nor is it an aldosterone antagonist. During treatment, aldosterone secretion may increase, which could lead to ethacrylic acid-induced hypokalemia. ...It irreversibly binds to two sulfhydryl groups of glyceraldehyde-3-phosphate dehydrogenase, thereby inactivating the enzyme. However, the diuretic effect cannot be attributed to this type of biochemical reaction...

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Therapeutic Uses
Diuretics
The primary use of loop diuretics is to treat acute pulmonary edema. The rapid increase in intravenous volume and rapid sodium excretion reduce left ventricular filling pressure, thus rapidly relieving pulmonary edema. Loop diuretics are also widely used to treat chronic congestive heart failure, particularly when reducing extracellular fluid volume to minimize venous and pulmonary congestion. Diuretics are also widely used to treat hypertension; controlled clinical trials have shown that Na+-Cl- cotransporter inhibitors (thiazides and thiazide-like diuretics) reduce morbidity and mortality, while Na+-K+-2Cl- cotransporter inhibitors do not. Nevertheless, Na+-K+-2Cl- cotransporter inhibitors appear to be as effective as Na+-Cl- cotransporter inhibitors in lowering blood pressure, with less impact on lipid profiles. /Loop Diuretics/ Edema caused by nephrotic syndrome is often unresponsive to other types of diuretics; loop diuretics are often the only medication capable of alleviating severe edema associated with this kidney disease. Loop diuretics are also used to treat edema and ascites caused by cirrhosis; however, care must be taken to avoid inducing encephalopathy or hepatorenal syndrome. For patients with drug overdose, loop diuretics can be used to induce forced diuresis to promote faster kidney clearance of the causative drug. /Loop Diuretics/
Loop diuretics, used in combination with isotonic saline to prevent volume depletion, are used to treat hypercalcemia. Loop diuretics interfere with the kidneys' ability to produce concentrated urine. Therefore, loop diuretics, used in combination with hypertonic saline, can be used to treat life-threatening hyponatremia. /Loop Diuretics/
For more complete data on the therapeutic uses of ethacrynic acid (10 in total), please visit the HSDB record page.

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Drug Warnings
Veterinarian: Rapid ototoxicity in cats. Contraindicated in patients with impaired renal function.
Routine use is not recommended during pregnancy. /Loop Diuretics/
Elderly patients may be more sensitive to the side effects of the usual adult dose.
Ethacrynic acid may cause gastrointestinal adverse reactions, including anorexia, abdominal discomfort or pain, nausea, vomiting, weakness, diarrhea, and dysphagia. Gastrointestinal adverse reactions most commonly occur after high-dose administration or continuous use for 1-3 months, and may require discontinuation. Severe, massive watery diarrhea may occur; if this occurs, the drug should be permanently discontinued. Gastrointestinal bleeding has been reported, most commonly in patients receiving intravenous ethacrynic acid sodium, especially those receiving heparin sodium concurrently. Acute necrotizing pancreatitis has been reported, accompanied by elevated serum amylase. For more complete data on ethacrynic acid (16 in total), please visit the HSDB record page. Pharmacodynamics: Ethacrynic acid is a monosulfonamide loop diuretic or a highly potent diuretic. Ethacrynic acid acts on the ascending limb of the loop of Henle and the proximal and distal tubules. Urine output is generally dose-related and depends on the degree of fluid retention. Because ethacrynic acid inhibits the reabsorption of filtered sodium by a much higher proportion than most other diuretics, its excretion of water and electrolytes may be several times higher than that of thiazide diuretics. Therefore, ethacrynic acid is effective for many patients with severely impaired renal function. Aside from rapid diuresis leading to a significant reduction in plasma volume, ethacrynic acid has almost no effect on glomerular filtration rate or renal blood flow.

C13H12CL2O4

303.14

302.011

C, 51.51; H, 3.99; Cl, 23.39; O, 21.11

58-54-8

Ethacrynic acid sodium;6500-81-8

3278

White to off-white solid powder

1.35g/cm3

480ºC at 760mmHg

125 °C

244.1ºC

3.605

1

4

6

19

370

0

ClC1C(=C(C([H])=C([H])C=1C(C(=C([H])[H])C([H])([H])C([H])([H])[H])=O)OC([H])([H])C(=O)O[H])Cl

AVOLMBLBETYQHX-UHFFFAOYSA-N

InChI=1S/C13H12Cl2O4/c1-3-7(2)13(18)8-4-5-9(12(15)11(8)14)19-6-10(16)17/h4-5H,2-3,6H2,1H3,(H,16,17)

2-[2,3-dichloro-4-(2-methylidenebutanoyl)phenoxy]acetic acid

Taladren; Ethacrynic acid; Etacrinic acid; Hydromedin; Otacril Reomax; Crinuryl; MK-595; Mingit; NSC 624008; NSC 85791

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO: 61~100 mg/mL (201.2~329.9 mM)
H2O: ~27.5 mg/mL (~90.7 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (8.25 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (8.25 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (8.25 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 1 mg/mL (3.30 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication.

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 (Please use freshly prepared in vivo formulations for optimal results.)