Administration Of Ethacrynic Acid Research Articles

Acetazolamide-Associated Acute Kidney Injury in Critically Ill Pediatric Patients.

Our objective was to determine the incidence and risk factors for intravenous acetazolamide-associated acute kidney injury (AKI). We utilized a retrospective cohort study including patients <19 years of age initiated on intravenous acetazolamide while admitted to an ICU. Data collection included patient demographics, clinical variables, acetazolamide dosing, and serum creatinine (SCr) values. Incidence of AKI was assessed per Kidney Disease Improving Global Outcomes criteria. Descriptive statistical analysis and ordinal logistic regression analysis were performed to determine the incidence of AKI and variables associated with AKI. A total of 868 patients met study criteria (male 55.8%, median age 0.66 years [IQR 0.19, 3.0 years]). Intravenous acetazolamide was administered at 5.1 ± 2.8 mg/kg/dose for a median of 4 doses (IQR 2, 6). Median baseline SCr was 0.28 mg/dL (IQR 0.22, 0.37), corresponding to a creatinine clearance of 115 ± 55 mL/min/1.73 m2. Acute kidney injury occurred in 26.8% (n = 233) of patients (stage I = 20.1%, stage II = 3.7%, stage III 3.1%), and no patients received renal replacement therapy. An ordinal logistic regression model identified an increased odds of AKI with cyclosporine, ethacrynic acid, and piperacillin-tazobactam administration. Acute kidney injury occurs frequently in critically ill pediatric patients receiving intravenous acetazolamide.

Repurposing ethacrynic acid for the treatment of bladder cancer.

521 Background: Bladder cancer is a common cancer in the US. Approximately seventy-five percent of new cases present as non-muscle invasive bladder cancer (NMIBC) with a high recurrence rate. Our group has demonstrated in well-characterized human NMIBC cell lines that ethacrynic acid (EA) suppresses growth by inhibiting proliferation, clonogenicity, spheroid formation and inducing apoptosis. Additionally, EA affects markers of stemness and may work through the NOTCH signaling pathway. We present a clinical trial characterizing the safety and urinary tract exposure to EA and metabolites following oral administration in patients undergoing transurethral resection of bladder tumor (TURBT). Methods: Institutional review board approval (#3674) was obtained for a Pilot trial in patients with presumed non-muscle invasive bladder cancer undergoing TURBT. All participants were given a single, 50 mg oral dose of EA in the pre-operative bay. Urine was collected at baseline, upon insertion of cystoscope (30-60 minutes post dose), and post-operatively. Urine concentrations of EA and metabolites were determined using a fully-validated UPLC-MS/MS-based analytical method. Participants were monitored for adverse events. Results: Twelve participants participated in the trial between August 2016 and February 2017. Eleven male and one female patient (median age 70.5 years) were enrolled. Final pathology demonstrated urothelial carcinoma in 5/12 (42%) subjects, three with high grade T1 and two with low-grade Ta tumors. Urine concentrations of EA and conjugates observed 30-60 minutes post-dose were as follows: EA 0.1 ug/mL, EA-glutathione 0.2 ug/mL, EA-cysteine 3 ug/mL, and EA-mercapturate 2 ug/mL. No drug-related adverse events were observed following oral EA administration. Conclusions: Despite EA receiving FDA approval over 40 years ago, our pilot trial describes for the first time, urinary tract exposure of EA and its active metabolites in bladder cancer patients after a single oral dose. These data are guiding ongoing preclinical proof of principle studies evaluating EA alone and in combination with standard of care agents in bladder cancer models. These studies warrant further studies of EA in patients with non-muscle invasive bladder cancer. Clinical trial information: NCT02852564.

Clinical Factors Associated with Dose of Loop Diuretics After Pediatric Cardiac Surgery: Post Hoc Analysis.

A post hoc analysis of a randomized controlled trial comparing the clinical effects of furosemide and ethacrynic acid was conducted. Infants undergoing cardiac surgery with cardiopulmonary bypass were included in order to explore which clinical factors are associated with diuretic dose in infants with congenital heart disease. Overall, 67 patients with median (interquartile range) age of 48 (13-139) days were enrolled. Median diuretic dose was 0.34 (0.25-0.4) mg/kg/h at the end of postoperative day (POD) 0 and it significantly decreased (p=0.04) over the following PODs; during this period, the ratio between urine output and diuretic dose increased significantly (p=0.04). Age (r -0.26, p=0.02), weight (r -0.28, p=0.01), cross-clamp time (r 0.27, p=0.03), administration of ethacrynic acid (OR 0.01, p=0.03), and, at the end of POD0, creatinine levels (r 0.3, p=0.009), renal near-infrared spectroscopy saturation (-0.44, p=0.008), whole-blood neutrophil gelatinase-associated lipocalin levels (r 0.30, p=0.01), pH (r -0.26, p=0.02), urinary volume (r -0.2755, p=0.03), and fluid balance (r 0.2577, p=0.0266) showed a significant association with diuretic dose. At multivariable logistic regression cross-clamp time (OR 1.007, p=0.04), use of ethacrynic acid (OR 0.2, p=0.01) and blood pH at the end of POD0 (OR 0.0001, p=0.03) was independently associated with diuretic dose. Early resistance to loop diuretics continuous infusion is evident in post-cardiac surgery infants: Higher doses are administered to patients with lower urinary output. Independently associated variables with diuretic dose in our population appeared to be cross-clamping time, the administration of ethacrynic acid, and blood pH.

Inhibition of Glutathione S-Transferase by Ethacrynic Acid Augments Ischemia-Reperfusion Damage and Apoptosis and Attenuates the Positive Effect of Ischemic Postconditioning in a Bilateral Acute Hindlimb Ischemia Rat Model

Aims: We studied the effects of the inhibition of the endogene antioxidant glutathione-S-transferase (GST) by ethacrynic acid (EA) on ischemia-reperfusion (IR) injury and postconditioning (PC) in the lower extremities. We aimed to examine the oxidative stress parameters (OSP), inflammatory response and activation of proapoptotic signaling proteins (PSP) after revascularization surgery. Methods: Sixty Wistar rats were divided into 6 groups: control, IR, PC, EA-control, IR and administration of EA (IR/EA) and PC and administration of EA (PC/EA). The IR, PC, IR/EA and PC/EA groups underwent 60 min of infrarenal aortic cross-clamping. After that, PC was performed in the PC and PC/EA groups. In 3 of the groups, the animals were treated with EA (EA-control, IR/EA and PC/EA groups) as well. The ischemia was followed by 120 min of reperfusion. Blood samples and biopsy specimens were collected from the quadriceps muscle. Plasma malondialdehyde, reduced glutathione, thiol/sulfhydryl group levels, TNF-α and IL-6 concentrations and superoxide-dismutase enzyme activity were measured. Results: The levels of the OSP and the inflammatory proteins were higher in the EA-administered groups. The ratio of phosphorylated PSP was higher in the EA-administered groups and the protective effect of PC did not develop. Conclusions: Inhibition of GST by EA augmented the IR damage. GST inhibition was associated with a different activation of the mitogen-activated protein kinases and the PSP, regulating these pathways in the process of apoptosis and PC.

Influence of ethacrynic acid on the anticonvulsant activity of conventional antiepileptic drugs in the mouse maximal electroshock seizure model

The aim of this study was to determine whether ethacrynic acid (EA), a loop diuretic with anticonvulsant activity, would affect the protective action of the conventional antiepileptics (AEDs) carbamazepine (CBZ), phenytoin (PHT), valproate (VPA) and phenobarbital (PB) in the mouse maximal electroshock seizure (MES) model. The effects of acute and chronic treatment with EA on these AEDs were examined. At a single dose of 100mg/kg ip, EA enhanced the antielectroshock activity of VPA, decreasing its ED50 value from 225.6 to 146.6mg/kg (p<0.05), but enhancement was not observed following continuous administration of EA (12.5mg/kg) for seven days. Combined treatment of EA with other AEDs had no effect on their ED50 values. The observed interaction between EA and VPA was pharmacodynamic in nature as EA did not alter free plasma (non-protein-bound) and total brain concentrations of VPA. Taking into consideration the clinical use of both drugs, this interaction between EA and VPA can be important for patients receiving these drugs.

Type 2 Pseudohypoaldosteronism: New Insights Into Renal Potassium, Sodium, and Chloride Handling

Type 2 Pseudohypoaldosteronism: New Insights Into Renal Potassium, Sodium, and Chloride Handling

Chinchilla models of selective cochlear hair cell loss

Although it is well known that ethacrynic acid (EA) can enhance gentamicin (GM) ototoxicity, there has been no systematic study of the relationship between dosing parameters and inner ear pathology. We examined the effects of two parameters, GM dose and time delay between GM and EA administration, on cochlear and vestibular hair cell loss in chinchillas. ‘No delay’ groups received one injection of GM (125, 40, 20, or 10 mg/kg i.m.) followed immediately by EA (40 mg/kg i.v.); ‘delay’ groups received GM (10 mg/kg i.m.) followed by EA 1 or 1.5 h later. Animals were sacrificed 7 days later for evaluation of hair cell loss in the cochlea and vestibular end organs (cristae, saccule and utricle). Vestibular function was assessed prior to sacrifice by measuring the duration of nystagmus induced by cold caloric stimulation. No delay groups had ∼100% loss of outer hair cells and dose-dependent losses of inner hair cells, ranging from ∼100% to 58%. In 1 and 1.5 h delay groups, inner hair cell losses were ∼19% and 0%, outer hair cell losses were ∼74% and 47%, and outer hair cell loss followed a typical base to apex gradient. Two results were remarkable. First, the three groups with partial inner hair cell loss showed an atypical lesion pattern in which losses were substantially greater in the apical half than in the basal half of the cochlea. Second, there was no vestibular pathology in any group. The results establish dosing parameters that can be used to produce animal models with defined patterns and magnitudes of cochlear hair cell damage, but normal vestibular function and morphology.

Topical gentamicin and ethacrynic acid: Effects on cochlear function

To determine whether concurrent intravenous administration of the loop diuretic ethacrynic acid potentiates the toxicity of the aminoglycoside antibiotic gentamicin applied topically on the round window. The authors studied the effects on cochlear sensitivity of co-administered intracardiac ethacrynic acid (40 mg/kg) and high-dose topical gentamicin solution (100%) applied to the round window. Comparisons were made with animals receiving ethacrynic acid plus systemic gentamicin (100 mg/kg); topical gentamicin alone; systemic gentamicin alone; and intravenous ethacrynic acid alone. Experiments were carried out on pigmented guinea pigs weighing 400 to 500 g. Changes in cochlear function were characterized by monitoring shifts in compound action potential (CAP) thresholds by use of chronic indwelling electrodes implanted at the round window, vertex, and contralateral mastoid. After 20 days animals receiving ethacrynic acid in combination with topical gentamicin to the round window failed to demonstrate a significant deterioration in cochlear sensitivity, whereas all animals receiving systemic gentamicin plus ethacrynic acid experienced profound increases in CAP thresholds. This study supports the contention that ethacrynic acid potentiates aminoglycoside ototoxicity by facilitating the entry of the antibiotics from the systemic circulation into the endolymph. In addition, this study answers important clinical concerns regarding the safety of the use of topical aminoglycoside agents in combination with loop diuretics.

O-152 - Induction of c-fos expression by intracerebro- ventricular administration of ethacrynic acid in mouse brain.

O-152 - Induction of c-fos expression by intracerebro- ventricular administration of ethacrynic acid in mouse brain.

Early and late increases of c- fos expression by intracerebroventricular administration of ethacrynic acid in mouse brain

Early and late increases of c- fos expression by intracerebroventricular administration of ethacrynic acid in mouse brain

On-line trace enrichment for the determination of ethacrynic acid in urine by liquid chromatography and column-switching

A chromatographic method based on liquid chromatography (LC) using column-switching for the determination of ethacrynic acid in urine samples, is described. The proposed system uses a Hypersil ODS-C18, 30 μm (20 mm × 2.1 mm i.d.) pre-column for the pre-concentration and separation of ethacrynic acid from the biological matrix. Polar urinary compounds are removed by flushing the pre-column with purified water, and the enriched analyte is then switched in back-flush mode onto an HP-LiChrospher RP C18, 5 μm (125 × 4 mm i.d.) analytical column, where it is chromatographed using an acetonitrile-acetate buffer gradient elution. The UV detector was set at 275 nm. The recovery of drug was 99 ± 2% in the 0.010–1.0 μg/ml concentration range. The limit of detection was 1 ng/ml, the total analysis time being less than 10 min. The reliability of this study has been tested by analyzing urine samples after minimum single dose (25 mg) administration of ethacrynic acid.

Chronic electrical stimulation reverses deafness-related depression of electrically evoked 2-deoxyglucose activity in the guinea pig inferior colliculus

The [ 14C]-2-deoxyglucose (2-DG) autoradiographic technique was used to study how auditory-related metabolic activity changes with deafness, and how chronic electrical stimulation of the deafened system may modify these changes. Guinea pigs were deafened by administration of kanamycin and ethacrynic acid. After nine weeks of deafness, the basal unstimulated uptake of 2-DG in the inferior colliculus (IC) was lower than in normal hearing control animals. 100 μA of acute cochlear electrical stimulation significantly increased 2-DG uptake in normal hearing animals but did not evoke a significant increase in four or nine week deafened animals. Electrically elicited 2-DG uptake in the IC is therefore depressed by prolonged deafness. In a second series of experiments, after four weeks of deafness, animals were chronically electrically stimulated via a cochlear implant 2.5-3.5 h a day, five days a week for five weeks at 100 μ,A. Acute cochlear electrical stimulation following this chronic stimulation significantly increased 2-DG uptake in the contralateral IC over unstimulated levels. This suggests that some depressive effects of profound deafness on the auditory brain stem may be reduced or reversed with chronic electrical stimulation by a cochlear implant.

Evidence for two discrete sources of 2f1-f2 distortion-product otoacoustic emission in rabbit. II: Differential physiological vulnerability.

In a previous report, it was shown that, in normal rabbit ears, the amplitude and phase of 2f1-f2 distortion-product otoacoustic emissions (DPOAEs) elicited by low-level (< 60-70 dB SPL) stimuli display a differential dependence on stimulus parameters to those evoked by high-level (> 60-70 dB SPL) stimuli, indicating differences in the underlying generation mechanisms. In the present study, the physiological vulnerability of DPOAEs in each of the two 2f1-f2 DPOAE-response regions identified on the basis of differential parametric properties, was characterized. Thus emissions evoked using stimulus levels from 45-75 dB SPL were measured over time upon: (1) induction of lethal anoxia, (2) acute injection of ethacrynic acid, and (3) acute injection of ethacrynic acid 2 h after a single administration of gentamicin. The DPOAEs evoked by low-level stimuli (45 dB SPL) were abolished within 3-4 min of induction of anoxia, whereas DPOAEs evoked by high-level stimuli (75 dB SPL) were unchanged in this period. The high-level emissions decreased with a complex time course postmortem, and demonstrated behaviors, including evidence of susceptibility to fatigue, suggesting a dependence upon a cochlear energy supply. Low-level DPOAEs could be temporarily abolished, with complete recovery, by an acute administration of ethacrynic acid that had little effect on high-level DPOAEs. Treatment with the gentamicin and ethacrynic-acid combination, which would be expected to produce widespread hair-cell damage, eliminated low-level DPOAEs, and greatly reduced high-level emissions. In combination with previously published data, these findings strongly suggest that low- and high-level 2f1-f2 DPOAEs arise from discrete sources. The data are consistent with the proposal that the low-level DPOAE source is an active, micromechanical process, but suggest that the proposed origin of high-level DPOAEs exclusively in the passive macromechanics of the cochlear partition may be incorrect. The elimination of both low- and high-level DPOAEs revealed the presence of a third, residual 2f1-f2 DPOAE component, approximately 75-80 dB below the stimulus-tone levels, that may reflect the true passive-distortion response of the cochlea.

The Effect of Intracamerally Injected Ethacrynic Acid on Intraocular Pressure in Patients with Glaucoma

We studied the effect of ethacrynic acid on intraocular pressure in eyes with advanced open-angle glaucoma. Five to 15 microliters of ethacrynic acid (3.3 to 9.8 micrograms) was injected intracamerally after retrobulbar anesthesia was achieved in five eyes of five patients with advanced glaucoma. Intraocular pressure before treatment ranged from 26 to 46 mm Hg with maximal medical treatment. A reduction in intraocular pressure from 9 to 31 mm Hg was observed in all patients three to 24 hours after treatment, and this effect lasted for three days, with a gradual return of intraocular pressure to pretreatment values one week after treatment. No acute corneal or anterior chamber side effects were observed and results of corneal endothelial cells counts were essentially unchanged two months after treatment. We suggest that ethacrynic acid may represent a new class of antiglaucoma medication. Intracameral administration of ethacrynic acid or a derivative might be contemplated in the future at the time of other ocular surgical procedures to treat short-term intraocular pressure increase.

Regulation of renal hemodynamics after protein feeding: effects of loop diuretics

These studies were designed to test the hypothesis that the renal vasodilation and increased glomerular filtration rate (GFR) after a high-protein meal are mediated by the tubuloglomerular feedback (TGF) mechanism. In eight chronically instrumented conscious dogs, a meal of raw beef (10 g/kg) caused GFR to increase from 66 +/- 5 to 90 +/- 7 ml/min and effective renal plasma flow (ERPF) to increase from 191 +/- 25 to 281 +/- 24 ml/min, while plasma alpha-amino N levels rose from 4.0 +/- 0.1 to 7.3 +/- 0.6 mg/dl. On another day the dogs were given an infusion of furosemide to block TGF, and fluid and salt losses were continuously replaced. Furosemide alone caused GFR to increase in most animals, although the average change did not reach statistical significance, and ERPF increased by 31%. Sodium excretion rose from 15 +/- 5 to 2,390 +/- 280 mueq/min, and urine flow rose from 1.17 +/- 0.22 to 20.5 +/- 2.4 ml/min. Autoregulatory capability was also abolished (autoregulatory index = 0.87 +/- 0.09 compared with 0.19 +/- 0.05 before furosemide). However, there was no significant change in GFR and ERPF after a subsequent meat meal in dogs receiving furosemide. On another day, some of the dogs were given another loop diuretic, ethacrynic acid, which caused no change in GFR, whereas its effects on ERPF, sodium excretion, and urine output were similar to those of furosemide. There were also no changes in GFR or ERPF after a meat meal during ethacrynic acid administration, despite normal increases in plasma alpha-amino N.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of acute and chronic respiratory alkalosis on preexisting chronic metabolic alkalosis

The severity of the alkalemia produced by a reduction in arterial carbon dioxide tension (PaCO2) in normal humans and animals is ameliorated by buffer and renal responses that diminish the levels of plasma bicarbonate concentration ([HCO3-]p). These adjustments have even greater potential importance in preventing extreme degrees of alkalemia when hypocapnia occurs in the presence of an initially elevated [HCO3-]p (mixed respiratory and metabolic alkalosis). The aim of the present study was to characterize the acute (approximately 3 h) and chronic (5 days) acid-base effects of respiratory alkalosis when superimposed on chronic metabolic alkalosis. Ten dogs were made alkalotic by the repeated administration of ethacrynic acid and the provision of a chloride-restricted diet. Hypocapnia (delta PaCO2 = 10 mmHg) was then superimposed by exposing the animals to 11% O2 in an environmental chamber. A large fall in [HCO3-]p occurred in the acute hypocapnic phase that was further augmented in the chronic phase; the corresponding delta [HCO3-]p/delta PaCO2 slopes were 0.43 and 0.71 meq.l-1.mmHg-1, respectively, values substantially larger than those previously reported for hypocapnia in normals as well as in animals with preexisting HCl acidosis. Hyperlactatemia was responsible, on average, for 43% of the decrement in [HCO3-]p during acute hypocapnia but for only 20% of the delta [HCO3-]p during the chronic phase of the study. The striking decrement in [HCO3-]p observed in response to the chronic reduction in PaCO2 was sufficient not only to prevent the development of extreme alkalemia but also to offset entirely the effect of hypocapnia on plasma [H+].

Stimulation of renin release by PGE2 and PGI2 infusion in the dog: enhancing effect of ureteral occlusion or administration of ethacrynic acid

This study on 19 anaesthetized dogs had two objectives. The first was to compare the potencies of PGE2 and PGI2 as stimulators of renin release and demonstrate their dependency on activation of intrarenal mechanisms for renin release. The second objective was to demonstrate that ethacrynic acid (ECA) increases renin release not as a stimulator, but by activating intrarenal mechanisms. After inhibiting renal prostaglandin synthesis by indomethacin, PGE2 and PGI2 infused into the aorta proximal to the renal arteries exerted no significant effects on renin release, but increased renin release during ureteral occlusion. At equimolar infusion rates, PGI2 increased renin release twice as much as PGE2, but this difference in potency may reflect differences in degradation since 86% of PGE2 and 29% of PGI2 (measured as 6-keto-PGF1 alpha) were degraded during one passage through the kidney. By infusing PGF2 at 8 nmol min-1 and PGI2 at 2 nmol min-1 renin release increased equally and the prostaglandin outputs increased to the same levels as during ureteral occlusion before indomethacin administration. ECA did not increase renin release after indomethacin administration. However, infusion of PGE2 during continuous ECA administration increased renin release in a dose-dependent manner similar to the experiments performed during ureteral occlusion. We conclude that PGI2 and PGE2 in the amounts synthesized in the kidney seem to be equally important stimulators of renin release but their relative potencies cannot be determined because the site of degradation is uncertain. Renin release is enhanced by intrarenal mechanisms activated by ECA infusion or ureteral occlusion, which both cause autoregulatory vasodilation and reduce NaCl reabsorption at the macula densa.

Evaluation of Eighth Nerve Integrity by the Electrically Evoked Middle Latency Response

A reliable objective test for estimating the number and distribution of surviving eighth nerve fibers needs to be identified for selection of candidates for cochlear implantation. Kanamycin and ethacrynic acid administration in guinea pigs resulted in graded amounts of eighth nerve degeneration over time. The electrically-induced middle latency response (EMLR) was acutely recorded in these animals at specific post-drug times, followed by the immediate killing of the animals, histologic preparation, and spiral ganglion cell density determination. Significant progressive spiral ganglion cell loss was noted by 4 weeks that increased over time. While EMLR threshold remained stable over time, the slope of the EMLR input/output function decreased with increasing post-drug intervals in a manner directly correlated with reduction in spiral ganglion cell density.

Intracerebroventricular injection of ethacrynic acid induces status epilepticus

The intracerebroventricular (i.c.v.) injection of ethacrynic acid to mice at a dose of more than 25 μg induced repeated tonic-clonic convulsions with subsequent death. Ethacrynic acid was more potent than other loop diuretics such as furosemide and bumetanide. Diazepam and 2-amino-5-phosphonovaleric acid notably reduced both the incidence of convulsion and the lethality seen after ethacrynic acid administration. Both phenobarbital and ketamine suppressed the incidence of convulsions but not the lethality. Without effects on the incidence of convulsions or lethality, dextromethorphan prolonged, while phenytoin or atropine shortened, the time to the onset of convulsion. Neither ethosuximide, carbamazepine, nor muscimol had a significant effect on the responses to ethacrynic acid. The present findings indicate that i.c.v. injected ethacrynic acid shows strong convulsive activity, probably due to impairment of Cl − transport processes, concomitant with enhancement of excitatory amino acid activity in the brain.

Uptake of Radioactive Sulphur in the Endolymphatic Sac:An Autoradiographic Study

Autoradiographic uptake of labelled sulphur (S35) in the endolymphatic sac was analysed after performing surgical labyrinthectomy and after systemic administration of glycerol and ethacrynic acid. Accumulation of radioactive substance was observed after surgical labyrinthectomy and associated with a deposition of stainable substance in the endolymphatic sac lumen. Increased activity was noted in the epithelial layer after administration of ethacrynic acid, whereas glycerol did not increase radioactivity in the endolymphatic sac despite the deposition of stainable substance therein. This fact was believed to depend on a too short time interval between the injection and the sacrifice of the animals, as well as a weaker concentration of the sulphated compound within the endolymphatic sac. The results suggest that the endolymphatic sac may secrete sulphur-containing substances presumably associated with a deposition of a stainable substance in the endolymphatic sac.