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
Onset of action is rapid, usually within 30 minutes after an oral dose of ethacrynic acid or within 5 minutes after an intravenous injection of ethacrynic acid.
Thirty-five % or less of ethacrynic acid was excreted in urine of rats and dogs, regardless of mode of admin and 50% or more appeared in feces, suggesting hepatic elimination of the drug.
Renal elimination (67%), biliary/fecal (33%), 20% unchanged. /From table/
Ethacrynic acid is rapidly absorbed from the GI tract. Following oral admin, the diuretic effect occurs within 30 min and reaches a peak in approx 2 hr. The duration of action following oral admin is usually 6-8 hr but may continue up to 12 hr. Following IV admin of ethacrynate sodium, diuresis usually occurs within 5 min, reached a max within 15-30 min, and persists for approx 2 hr. In animals, substantial quantities of ethacrynic acid accumulate only in the liver. The drug does not enter the CSF. It is not known whether ethacrynic acid crosses the placenta or is distributed into milk in humans. ... Approx 30-65% of an IV dose of ethacrynate sodium is secreted by the proximal renal tubules and is excreted in urine; approx 35-40% is excreted in bile, partially as the cysteine conjugate. In dogs, approx 30-40% of the drug excreted in urine is unchanged, 20-30% is the cysteine conjugate, and 33-40% is an unstable, unidentified compound. The rate of urinary excretion of ethacrynic acid increases as urinary pH increases and is decreased by probenecid.

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Metabolism / Metabolites
Hepatic.
After iv admin (5 or 50 mg/kg) of (14)C-ethacrynic acid to rats 60-70% was excreted into bile within 4 hr; <25% was ethacrynic acid, the remainder was biotransformation products. The 2 major metabolites in bile were identified; one was the glutathione adduct (ethacrynic acid-GSH) and the other was ethacrynic acid-mercapturate. Approx 40% of either dose was excreted as ethacrynic acid-GSH. Ethacrynic acid-mercapturate accounted for 18% of the low dose and 30% of the high dose excreted into bile. Dogs given a 5 mg/kg dose (iv) excreted 25, 11, and 9% of the dose as ethacrynic acid-mercapturate, ethacrynic acid-cysteine and ethacrynic acid-GSH, respectively.
Animal studies indicate that ethacrynic acid is metabolized to a cysteine conjugate (which may contribute to the pharmacologic effects of the drug) and to an unstable, unidentified compound.

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Because no information is available on the use of ethacrynic acid during breastfeeding and because intense diuresis might decrease lactation, an alternate drug may be preferred, especially while nursing a newborn or preterm infant. Low doses of ethacrynic acid may not suppress lactation.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Ethacrynic acid was reportedly used successfully to suppress lactation in 6 postpartum women who did not want to breastfeed and to decrease the intensity of milk production in another. The added contribution of the diuretic to the other measures, which are effective in suppressing lactation, has not been studied. No data exist on the effects of loop diuretics on established, ongoing lactation.

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Protein Binding
> 98%

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Interactions
The high-ceiling diuretics may interact adversely with other drugs. Ethacrynic acid and furosemide are significantly bound to plasma albumin and may compete for sites on the protein with drugs such as warfarin and clofibrate. ...One should be judicious in the use of any cephalosporin in conjunction with...ethacrynic acid.
The ototoxic interaction between aminoglycoside antibiotics (Streptomycin, Kanamycin, etc.) and loop-inhibiting diuretics, such as ethacrynic acid, has been well documented. This interaction causes extensive destruction of the hair cells of the cochlea. Viomycin, Capreomycin, and Polymyxin B, when given with ethacrynic acid , were found to produce cochlear hair cell damage that was similar to that produced by aminoglycoside antibiotics admin with ethacrynic acid.
Treatment of mice with Neomycin (100 mg/kg bw, IM) 60 min prior to ethacrynic acid led to a 3-5 fold higher accumulation of ethacrynic acid in cochlear structures. It is suggested that Neomycin breaks down hemolabyrinthine or tissue permeability barriers and allows increased penetration of the other drug into the inner ear.
The temporal bones of a patient who suffered sudden deafness and ataxia after admin of both furosemide and ethacrynic acid, were examined by light and electron microscopy. There was no loss of hair or supporting cells. Some hair cells, in both the vestibular neuroepithelium and the organ of corti, particularly in the basal turn, were more densely staining and more granular than normal. Membrane whorls also were common within mitochondria of such cells. The endoplasmic reticulum of some spiral ganglion cells was dilated. The major cytologic changes were found in the stria vascularis of the cochlea and dark cell areas of the vestibular system. There was marked dilatation of the intercellular fluid spaces, consistent with the biochemical observation that loop diuretics interfere first with enzyme systems responsible for fluid transport within the inner ear.
For more Interactions (Complete) data for ETHACRYNIC ACID (11 total), please visit the HSDB record page.

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Non-Human Toxicity Values
LD50 Mouse iv 175 mg/kg /Ethacrynate sodium/
LD50 Mouse oral 627 mg/kg
LD50 Rat oral 1 g/kg
LD50 Rat ip 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)
Etacrynic acid is an aromatic ether that is phenoxyacetic acid in which the phenyl ring is substituted by chlorines at positions 2 and 3, and by a 2-methylidenebutanoyl group at position 4. It is a loop diuretic used to treat high blood pressure resulting from diseases such as congestive heart failure, liver failure, and kidney failure. It is also a glutathione S-transferase (EC 2.5.1.18) inhibitor. It has a role as an ion transport inhibitor, an EC 2.5.1.18 (glutathione transferase) inhibitor and a loop diuretic. It is an aromatic ether, a monocarboxylic acid, an aromatic ketone and a dichlorobenzene. It is functionally related to an acetic acid.
A compound that inhibits symport of sodium, potassium, and chloride primarily in the ascending limb of Henle, but also in the proximal and distal tubules. This pharmacological action results in excretion of these ions, increased urinary output, and reduction in extracellular fluid. This compound has been classified as a loop or high ceiling diuretic.
Ethacrynic acid is a Loop Diuretic. The physiologic effect of ethacrynic acid is by means of Increased Diuresis at Loop of Henle.
Ethacrynic Acid is an unsaturated ketone derivative of aryloxyacetic acid without a sulfonamide substituent belonging to the class of loop diuretics. Ethacrynic acid is extensively bound to plasma proteins; both ethacrynic acid in its unchanged form as well as its metabolites are excreted in bile and urine.
A compound that inhibits symport of sodium, potassium, and chloride primarily in the ascending limb of Henle, but also in the proximal and distal tubules. This pharmacological action results in excretion of these ions, increased urinary output, and reduction in extracellular fluid. This compound has been classified as a loop or high ceiling diuretic.

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Drug Indication
For the treatment of high blood pressure and edema caused by diseases like congestive heart failure, liver failure, and kidney failure.
FDA Label

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Mechanism of Action
Ethacrynic acid inhibits symport of sodium, potassium, and chloride primarily in the ascending limb of Henle, but also in the proximal and distal tubules. This pharmacological action results in excretion of these ions, increased urinary output, and reduction in extracellular fluid. Diuretics also lower blood pressure initially by reducing plasma and extracellular fluid volume; cardiac output also decreases, explaining its antihypertensive action. Eventually, cardiac output returns to normal with an accompanying decrease in peripheral resistance. Its mode of action does not involve carbonic anhydrase inhibition.
Optimal diuretic activity depends on at least 2 structural requirements: (1) methylene and adjacent ketone groups capable of reacting with sulfhydryl radicals of presumed receptor, and (2) substituents on aromatic nucleus.
In vitro, ethacrynic acid inhibits the active transport of chloride in the lumen of the ascending limb of the loop of Henle, thereby diminishing reabsorption of sodium and chloride at that site. Because this inhibition occurred with lower concns of ethacrynic acid in the presence of cysteine, it has been proposed that the ethacrynate-cysteine metabolite is the most active form of the drug. The drug increases potassium excretion in the distal renal tubule. Ethacrynic acid does not inhibit carbonic anhydrase, and it is not an aldosterone antagonist. Aldosterone secretion may incr during therapy with the drug and may contribute to the hypokalemia caused by ethacrynic acid.
...IRREVERSIBLY COMBINES WITH 2 THIOL GROUPS OF GLYCERALDEHYDE 3-PHOSPHATE DEHYDROGENASE, THUS INACTIVATING THE ENZYME. HOWEVER, IT IS NOT POSSIBLE TO ATTRIBUTE DIURETIC ACTION TO THIS TYPE OF BIOCHEMICAL REACTION...

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Therapeutic Uses
Diuretics
A major use of loop diuretics is in the treatment of acute pulmonary edema. A rapid incr in venous capacitance in conjunction with a brisk natriuresis reduces left ventricular filling pressures and thereby rapidly relieves pulmonary edema. Loop diuretics also are widely used for the treatment of chronic congestive heart failure when diminution of extracellular fluid volume is desirable to minimize venous and pulmonary congestion. Diuretics are widely used for the treatment of hypertension, and controlled clinical trials demonstrating reduced morbidity and mortality have been conducted with Na+-Cl- symport (thiazides and thiazide-like diuretics), but not Na+-K+-2Cl- symport, inhibitors. Nonetheless, Na+-K+-2Cl- symport inhibitors appear to lower blood pressure as effectively as Na+-Cl- symport inhibitors while causing smaller perturbations in the lipid profile. /Loop diuretics/
The edema of nephrotic syndrome often is refractory to other classes of diuretics, and loop diuretics often are the only drugs capable of reducing the massive edema associated with this renal disease. Loop diuretics also are employed in the treatment of edema and ascites of liver cirrhosis; however, care must be taken not to induce encephalopathy or hepatorenal syndrome. In patients with a drug overdose, loop diuretics can be used to induce a forced diuresis to facilitate more rapid renal elimination of the offending drug. /Loop diuretics/
Loop diuretics- combined with isotonic saline admin to prevent volume depletion- are used to treat hypercalcemia. Loop diuretics interfere with the kidney's ability to produce a concentrated urine. Consequently, loop diuretics combined with hypertonic saline are useful for the treatment of life-threatening hyponatremia. /Loop diuretics/
For more Therapeutic Uses (Complete) data for ETHACRYNIC ACID (10 total), please visit the HSDB record page.

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Drug Warnings
Vet: Rapid ototoxicity in cats. Do not admin in cases of decr renal function.
Not recommended for routine use /in pregnancy/. /Loop diuretics/
Geriatric patients may be more sensitive to the effects of the usual adult dose.
Ethacrynic acid may cause adverse GI effects, including anorexia, abdominal discomfort or pain, nausea, vomiting, malaise, diarrhea, and dysphagia. Adverse GI effects occur most frequently when large doses are employed or after 1-3 months of continuous therapy and may necessitate discontinuing the drug. Severe, profuse, watery diarrhea may occur; the drug should be permanently discontinued if this occurs. GI bleeding has been reported, most frequently in patients receiving IV ethacrynate sodium therapy and especially in patients receiving heparin sodium concomitiantly. Acute necrotizing pancreatitis, with an incr in serum amylase, has been reported.
For more Drug Warnings (Complete) data for ETHACRYNIC ACID (16 total), please visit the HSDB record page.

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Pharmacodynamics
Ethacrynic acid is a monosulfonamyl loop or high ceiling diuretic. Ethacrynic acid acts on the ascending limb of the loop of Henle and on the proximal and distal tubules. Urinary output is usually dose dependent and related to the magnitude of fluid accumulation. Water and electrolyte excretion may be increased several times over that observed with thiazide diuretics, since ethacrynic acid inhibits reabsorption of a much greater proportion of filtered sodium than most other diuretic agents. Therefore, ethacrynic acid is effective in many patients who have significant degrees of renal insufficiency. Ethacrynic acid has little or no effect on glomerular filtration or on renal blood flow, except following pronounced reductions in plasma volume when associated with rapid diuresis.

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.)