Vasopressin V2 Receptor Antagonist Research Articles

Tolvaptan Safety in Autosomal Dominant Polycystic Kidney Disease; Focus on Idiosyncratic Drug Induced Liver Injury Liabilities.

Tolvaptan is a vasopressin V2 receptor antagonist which has proven to be an effective and mostly well-tolerated agent for the treatment of autosomal dominant polycystic kidney disease (ADPKD). However, its administration is associated with rare but serious idiosyncratic liver injury, which has warranted a black box warning on the drug labels and frequent monitoring of liver blood tests in the clinic. This review outlines mechanistic investigations that have been conducted to date and constructs a working narrative as explanation for the IDILI events that have occurred thus far. Potential risk factors which may contribute to individual susceptibility to DILI reactions are addressed, and key areas for future investigative/clinical development are highlighted.

Evaluating the Safety and effectivenesS in adult KorEaN patients treated with Tolvaptan for management of autosomal domInAnt poLycystic kidney disease (ESSENTIAL): final report.

Tolvaptan, a selective vasopressin V2 receptor antagonist, was first approved by the Korean Ministry of Food and Drug Safety in 2015 as a treatment option for autosomal dominant polycystic kidney disease (ADPKD). To prescribe tolvaptan safely and effectively, we designed the phase 4 clinical trial among Korean ADPKD patients with chronic kidney disease stages 1 to 3. A total of 117 Korean patients aged 19 to 50 years with rapidly progressing ADPKD were enrolled in the study. Tolvaptan was prescribed for 24 months with the maximum tolerable dose up to 120 mg/day. The primary outcome was the incidence of treatment-emergent adverse events (TEAEs) including hepatic adverse events. The secondary outcomes were the annual mean percent change of total kidney volume (TKV) and the annual mean change of estimated glomerular filtration rate (eGFR). A total of 489 TEAEs occurred in 106 patients (90.6%). A total of 17 cases of hepatic adverse events (14.5%) occurred during the study period and mostly within the first 18-month period. However, liver enzymes were normalized after drug discontinuation. Although it was not statistically significant, patients with a previous history of liver disease as well as those with mild elevation of liver enzyme showed a higher frequency of hepatic adverse events. Compared with the predicted value from the calculation, tolvaptan attenuated both TKV growth and eGFR decline rate. Although the incidence of hepatic adverse events was higher in Korean ADPKD patients compared to the previous studies, tolvaptan can be prescribed safely and effectively using meticulous titration and 1-month interval monitoring.

Update on Tolvaptan for the Treatment of Refractory Ascites in Liver Cirrhosis

Ascites is the most prevalent complication of decompensated cirrhosis, and approximately 5%-10% of cirrhotic ascites will develop into refractory ascites (RA). With complicated pathogenesis, obscure treatment strategies and poor prognosis, it is still a challenge for physicians to manage RA properly. Tolvaptan (TLV) is a new type of non-peptide selective arginine vasopressin V2 receptor antagonist targeting at suppressing renal water reabsorption, promoting free water excretion and raising blood sodium levels, which provides a new option for the treatment of RA in liver cirrhosis. In this review, we summarized the mechanisms of TLV's effect and described its efficacy, safety and predictive factors of response in treating RA, intending to provide a supplement for clinical application of tolvaptan in the management of RA.

Prognostic effect of a vasopressin V2 receptor antagonist in acute congestive heart failure patients with hypoperfusion, the wet-cold pattern.

This study investigated whether the oral vasopressin V2 receptor antagonist tolvaptan has beneficial effects on mortality in real-world congestive heart failure (CHF) patients with hypoperfusion (i.e. the wet-cold pattern), from the viewpoint of cardiorenal syndrome. Data on 5511 consecutive CHF patients were extracted from the Tokyo CCU Network data registry. Congestion and hypoperfusion were defined by Nohria-Stevenson clinical profiles at the time of hospitalization. Propensity scores for tolvaptan use were calculated for each patient and used to assemble two matched cohorts of patients receiving tolvaptan or not in the CHF with and without hypoperfusion groups. Of the entire study cohort, 1073 patients (19%) had CHF with hypoperfusion (i.e. the wet-cold pattern). In-hospital mortality was significantly higher for CHF patients with than without hypoperfusion (log-rank, P < 0.001). The rate of tolvaptan use did not differ significantly between CHF patients with and without hypoperfusion (15% vs. 14%, respectively; P = 0.7848). In the propensity-matched CHF with hypoperfusion cohort, there was a significant association between the use of tolvaptan and a reduction in in-hospital mortality (log-rank, P = 0.0052). Conversely, in the matched CHF without hypoperfusion cohort, tolvaptan use was not associated with in-hospital mortality (log-rank, P = 0.4417). There was a significant association between the use of tolvaptan and a reduction in in-hospital mortality in CHF patients with, but not without, hypoperfusion. These findings hint at possible individualized therapies for patients with CHF.

A Synthetic Route to Tetrahydro-1H-azepino[4,3,2-cd]indoles via Ring-Opening Cyclization of Activated Azetidines with 4-Bromoindole: Toward a Vasopressin V2 Receptor Antagonist.

A simple one-pot, two-step strategy for the synthesis of tetrahydro-1H-azepino[4,3,2-cd]indoles via Lewis acid-catalyzed SN2-type ring opening of activated azetidines with 4-bromoindole, followed by a Pd-catalyzed intramolecular C-N cyclization reaction, with good to excellent yields is described. Utilizing this protocol, the vasopressin V2 receptor antagonist precursor has been synthesized easily. Enantioenriched tetrahydro-1H-azepino[4,3,2-cd]indoles were obtained by starting from enantiopure azetidine.

Tolvaptan therapy for edema in patients with chronic kidney disease.

Tolvaptan is a vasopressin V2 receptor antagonist that is commonly prescribed to alleviate edema associated with renal diseases. However, the clinical benefits of tolvaptan in chronic kidney disease (CKD) remain unclear. This study aimed to evaluate the effectiveness of tolvaptan in managing edema caused by CKD. The efficacy and treatment regimen of tolvaptan were assessed in a cohort of 96 patients with renal edema and CKD. During the treatment, the patients' creatinine (CR), uric acid (UA), and estimated glomerular filtration rate (eGFR) were monitored as important indicators of kidney function. Coagulation-associated molecules including fibrinogen, D-dimer, and fibrin degradation products (FDPs) were measured. Electrolyte disorders and acute kidney injury were closely monitored. Tolvaptan was administered at a daily dose of 7.5 mg, and 30 mg of edoxaban was administered to manage deep vein thrombosis. During the course of tolvaptan therapy, the eGFR of the patients was not declined. Edema was eliminated in 82.18% of patients. Proteinuria was reduced in the patients (p<0.05). There were no significant changes in serum sodium levels throughout treatment, and no significant difference was observed in blood volume between the end of treatment and baseline levels. Importantly, acute kidney injury did not occur, and renal edema and deep vein thrombosis were successfully treated. As long as a rational treatment regimen is followed, tolvaptan is a safe and effective diuretic for treating edema in CKD, even in the late stages of CKD without reducing residual renal function in the patients.

#2119 Long-term efficacy of tolvaptan therapy in patients with ADPKD

Abstract Background and Aims Currently, the only available therapy to ameliorate disease progression in patients with autosomal dominant polycystic kidney disease (ADPKD) is tolvaptan, a vasopressin V2 receptor antagonist. Real-life data on tolvaptan treatment effect is sparce, with several limitations including restricted follow-up, relatively small patient groups, no control groups, or only data reported on kidney function without total kidney volume. We studied, therefore, the long-term effect of tolvaptan on kidney function as well as kidney growth in a relatively large number of real-life ADPKD patients and controls. Moreover, we investigated the effect of salt and protein intake on long-term treatment efficacy. Method Data from two national ADPKD cohorts were pooled. Kidney function (creatinine-based eGFR) was measured at least yearly and total kidney volume (TKV, measured by MRI or CT) at least 3-yearly. Salt and protein intake were measured by 24 h urine excretion. To investigate the long-term effects of tolvaptan we assessed change in eGFR and TKV before as well as after start of tolvaptan using linear mixed effects models. For this purpose, we excluded the acute treatment effect from start to 6 months after initiation of tolvaptan. As a control group, we included all patients who were not treated with tolvaptan, assessing change in eGFR and TKV before and after the theoretical start of treatment (based on the average time of tolvaptan initiation observed in the tolvaptan-treated group) as well as a matched control group. Subgroup analyses of salt and protein intake were based on the median urinary excretion of sodium or urea. Results 697 patients (47 ± 12 years, 59.1% female) were included, of which 104 patients used tolvaptan. Mean duration of tolvaptan use was 6.0 ± 4.5 years (range: 0.8 to 15.6). Tolvaptan use reduced yearly eGFR decline by 17.4% (−4.43 to −3.66 mL/min/1.73 m2/year, p = 0.03, number of measurements: n = 817), whereas in the non-tolvaptan control group after the theoretical start of treatment, eGFR decline increased by 13.3% (−1.95 to −2.21 mL/min/1.73 m2/year, p = 0.2, n = 2804). Long-term TKV growth did not change after start of tolvaptan treatment (4.90 to 5.53%/year, p = 0.5, n = 316). Similar results were obtained in the matched control group. A more substantial treatment effect of tolvaptan on eGFR slope was noted in patients with high compared to low salt intake (assessed as ≥ versus &amp;lt; median urinary sodium excretion of 146 mmol/24 h (difference 1.62 (0.22 to 3.02) mL/min/1.73 m2/year, p = 0.02). Subgroup analysis according to median protein intake did not show a significant difference in tolvaptan treatment effect. Conclusion In this study, with real-life patient data, long-term follow-up, and a control group, we found that tolvaptan attenuated long-term kidney function decline but, notably, did not influence kidney growth. Higher daily salt intake was associated with a more substantial tolvaptan treatment effect, perhaps due to higher vasopressin levels before treatment, and consequently more vasopressin antagonism by tolvaptan.

#1636 Treatment of Tolvaptan related polyuria with bendroflumethiazide for ADPKD: Does it really work?

Abstract Background and Aims Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary renal disease worldwide and accounts for 10% of patients on renal replacement therapy. Currently, the arginine vasopressin (AVP) V2 receptor antagonist Tolvaptan is the only available treatment for ADPKD which slows cyst formation and thus the progression of kidney disease by inducing AVP resistance. However, its aquaretic side effects can be debilitating and is the most common reason for medication discontinuation. Thiazides such as bendroflumethiazide are natriuresis-promoting diuretics through their action on the sodium-chloride channel in the distal convoluted tubule that are widely used to treat polyuria in inherited AVP deficiency or resistance. However, there is limited information about their effect in patients treated with Tolvaptan. The aim of this observational study is to review the impact on patients’ quality of life by using a low dose bendroflumethiazide with Tolvaptan in patients with ADPKD who are suffering from Tolvaptan induced aquaretic side effects. Method Details of all patients with ADPKD who are on Tolvaptan with or without bendroflumethiazide who are currently attending the polycystic kidney disease (PKD) clinic at Royal Free London NHS Foundation Trust were obtained, and their medications reviewed. Patients who have previously been or were currently on bendroflumethiazide to enable them to continue Tolvaptan therapy were identified. Information about the impact of bendroflumethiazide on their quality of life and their aquaretic side effects were obtained via phone call. If they discontinued bendroflumethiazide, the reason for this was explored. In addition, eGFR, sodium, potassium, and calcium at the time of bendroflumethiazide initiation as well as at three, six, nine and twelve months post bendroflumethiazide initiation were obtained. Results Out of 136 patients receiving Tolvaptan for treatment of ADPKD at our centre, eight (5.8%) were prescribed bendroflumethiazide for treatment of their aquaretic side effects from Tolvaptan. Two of these eight patients (25%) stopped bendroflumethiazide due to adverse reactions. The remaining six patients (75%) remained on the medication, and all reported significant subjective improvement in their symptoms of polyuria, nocturia and in their overall quality of life. Two of the six patients (33.3%) that remained on bendroflumethiazide had also subsequently increased their Tolvaptan dose. No electrolyte disturbances were noted after initiation of bendroflumethiazide. Conclusion Using bendroflumethiazide appears to improve the quality of life through reduction of polyuria and nocturia in patients suffering from Tolvaptan-induced aquaretic side effects with some patients subsequently able to increase their Tolvaptan dose by taking bendroflumethiazide which might result in augmented therapeutic benefit of Tolvaptan. Further placebo-controlled randomised studies with longitudinal will be needed to determine the true benefit-disbenefit balance of thiazide therapy in patients taking tolvaptan, especially to determine whether there is a negative effect on efficacy of tolvaptan on the underlying ADPKD. However, based on our small observational study, the number of patients needed to determine whether bendroflumethiazide improves the tolerability and medication adherence in patients who are debilitated by the aquaretic side effects of Tolvaptan would be small.

#1891 Evaluating the safety and effectiveness of Tolvaptan for management of adult Korean ADPKD patients (ESSENTIAL study): final report

Abstract Background and Aims Tolvaptan, a selective vasopressin V2 receptor antagonist, was first approved by Korean FDA in 2015 as a treatment option in autosomal dominant polycystic kidney disease (ADPKD). In order to prescribe Tolvaptan safely and effectively, we designed the phase 4 clinical trial among Korean ADPKD patients with chronic kidney disease (CKD) stage 1-3. Method Korean patients aged 19 to 50 with rapidly progressing ADPKD were enrolled in the study. The dose titration was performed every one week for a total of 4 weeks. The patient was prescribed Tolvaptan with the maximum tolerable dose up to 120 mg per day. A total duration of Tolvaptan prescription was 24 months. The primary outcome was the incidence of treatment emergent adverse events (TEAE) including drug-induced liver injury (DILI). The secondary outcomes were the annual mean percent change of total kidney volume (TKV) and the annual mean change of estimated glomerular filtration rate (eGFR). Results A total of 117 patients were included in the analysis. Mean age was 38.7 ± 8.4 years old and male were predominant (58.1%). The average TKV was 2066 ± 1094 mL and mean eGFR was 79.7 ± 27.7 mL/min/1.73 m2. Mean duration of Tolvaptan exposure was 1.7 ± 0.6 years and the average daily dose of Tolvaptan was 94.4 ± 24.1 mg/day. A total of 489 treatment-emergent adverse events (TEAE) occurred in 106 (90.6%) patients during study duration. The drug-induced liver injury and aquaresis-related adverse events were two most common adverse events. A total of 17 DILI cases (14.5%) occurred during the study period and mostly within 18-month period. However, liver enzymes were normalized after drug discontinuation The patients with previous history of liver disease as well as those who were prescribed higher dose of Tolvaptan demonstrated higher frequency of DILI. Mean growth rate of TKV after Tolvaptan treatment was 4.5 ± 0.5% and mean eGFR decline rate was -3.0 ± 0.39 mL/min/1.73 m2/year. Comparing with the predicted value from calculation, Tolvaptan attenuated both TKV growth and eGFR decline rate. Conclusion This study is the first post-marketing survey assessing the safety and efficacy of Tolvaptan in Korean ADPKD patients. The incidence of DILI was higher than the previous studies and especially in those with liver disease and higher Tolvaptan prescription dose. While Tolvaptan can effectively reduce TKV and attenuate eGFR decline, the clinicians should be aware of higher frequency of DILI among Korean population.

Antiproliferative role of the vasopressin V2 receptor antagonist tolvaptan in a murine xenograft model of small cell lung cancer

Antiproliferative role of the vasopressin V2 receptor antagonist tolvaptan in a murine xenograft model of small cell lung cancer

Long-Residence Time Peptide Antagonist for the Vasopressin V2 Receptor to Treat Autosomal Dominant Polycystic Kidney Disease.

The dysregulated intracellular cAMP in the kidneys drives cystogenesis and progression in autosomal dominant polycystic kidney disease (ADPKD). Mounting evidence supports that vasopressin V2 receptor (V2R) antagonism effectively reduces cAMP levels, validating this receptor as a therapeutic target. Tolvaptan, an FDA-approved V2R antagonist, shows limitations in its clinical efficacy for ADPKD treatment. Therefore, the pursuit of better-in-class V2R antagonists with an improved efficacy remains pressing. Herein, we synthesized a set of peptide V2R antagonists. Peptide 33 exhibited a high binding affinity for the V2R (Ki = 6.1 ± 1.5 nM) and an extended residence time of 20 ± 1 min, 2-fold that of tolvaptan. This prolonged interaction translated into sustained suppression of cAMP production in washout experiments. Furthermore, peptide 33 exhibited improved efficacies over tolvaptan in both ex vivo and in vivo models of ADPKD, underscoring its potential as a promising lead compound for the treatment of ADPKD.

Detection of Inflammatory Signaling in Individuals with Bardet-Biedl Syndrome Presenting Symptoms of Polycystic Kidney Disease

Context: Bardet-Biedl syndrome is a rare genetic disorder with variable prevalence rates across populations, characterized by symptoms such as retinal degeneration and intellectual disability. In this study, researchers investigated renal cystic epithelia from patients with PKD1 mutations. This study identified the upregulation of genes related to the Jak-STAT pathway and NF-κB signaling in these renal cells. These pathways appear to be crucial in regulating immune responses within cystic epithelial and renal cell types in PKD-affected kidneys. Evidence Acquisition: This study was carried out through a literature search with the keywords of polycystic kidney disease (PKD), Newborn, and Bardet-Biedl syndrome (BBS), combined with Drug Therapy in Scopes, PubMed, and Web of Science. This study included relevant articles (i.e., randomized controlled trials, observational studies, guidelines, and reviews) written in English and published between 2000 and 2023. Results: Recent genome-wide expression analyses have provided valuable insights into the molecular mechanisms associated with PKD. The Jak-STAT system, essential for immune signaling, can be activated by cytokines, such as interleukin 6 (IL-6) and interferon-gamma (IFN-γ). Conclusions: Promising developments in the treatment of PKD have emerged from studies involving immune-modulating drugs in animal models. Glucocorticoids and rosmarinic acid exhibited positive effects, reducing cystic indices and preserving renal function in PKD mice and rats. Mycophenolate mofetil, an immunosuppressive drug, showed effectiveness in reducing cyst area, inflammation, and fibrosis in rat models. Additionally, COX-2 inhibitors, PPARγ agonists, and vasopressin V2 receptor antagonists demonstrated potential in slowing cystic disease progression.

Long-Term Effects of Tolvaptan in Autosomal Dominant Polycystic Kidney Disease: Predictors of Treatment Response and Safety over 6 Years of Continuous Therapy.

Tolvaptan, an oral vasopressin V2 receptor antagonist, reduces renal volume expansion and loss of renal function in patients with autosomal dominant polycystic kidney disease (ADPKD). Data for predictive factors indicating patients more likely to benefit from long-term tolvaptan are lacking. Data were retrospectively collected from 55 patients on tolvaptan for 6 years. Changes in renal function, progression of renal dysfunction (estimated glomerular filtration rate [eGFR], 1-year change in eGFR [ΔeGFR/year]), and renal volume (total kidney volume [TKV], percentage 1-year change in TKV [ΔTKV%/year]) were evaluated at 3-years pre-tolvaptan, at baseline, and at 6 years. In 76.4% of patients, ΔeGFR/year improved at 6 years. The average 6-year ΔeGFR/year (range) minus baseline ΔeGFR/year: 3.024 (-8.77-20.58 mL/min/1.73 m2). The increase in TKV was reduced for the first 3 years. A higher BMI was associated with less of an improvement in ΔeGFR (p = 0.027), and family history was associated with more of an improvement in ΔeGFR (p = 0.044). Hypernatremia was generally mild; 3 patients had moderate-to-severe hyponatremia due to prolonged, excessive water intake in response to water diuresis-a side effect of tolvaptan. Family history of ADPKD and baseline BMI were contributing factors for ΔeGFR/year improvement on tolvaptan. Hyponatremia should be monitored with long-term tolvaptan administration.

Pharmacokinetics, pharmacodynamics and safety of 15mg-tolvaptan administered orally for 7 consecutive days to Chinese patients with child-Pugh B cirrhosis.

Background: Tolvaptan, a selective vasopressin V2-receptor antagonist, can elicit a diuretic effect without significant electrolyte loss. The aims were to evaluate multiple-dose pharmacokinetics, pharmacodynamics and safety of daily administration of 15mg tolvaptan in Chinese adult patients with confirmed Child-Pugh Class B cirrhosis accompanied by ascites. Methods: This was an open-label, single-center, single- and multiple-dose study. All patients received a daily 15mg dose of tolvaptan for 7 consecutive days. The plasma concentrations of tolvaptan and its two metabolites (DM-4103, DM-4107) were measured using high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS). In addition, various pharmacokinetics parameters were calculated. The pharmacodynamic outcomes evaluated changes in serum sodium and potassium concentrations, daily urine volume, daily water consumption, fluid balance and body weight. Safety profiles, including the incidence of treatment-emergent adverse events (TEAEs), were carefully recorded. Results: Eleven patients with Child-Pugh B cirrhosis were eventually enrolled in the study. Plasma concentrations of tolvaptan and DM-4107 reached steady-states after 7 days of consecutive oral administration. No accumulation of tolvaptan or DM-4107 was found, but DM-4103 accumulated 18.2-fold after multiple-dosing. The daily urine volume and daily water consumption were statistically significantly increased after administration of tolvaptan from Day 1 to Day 7 (all p < 0.05), accompanied by an increased serum sodium concentration. Of 11 patients, 9 (81.8%) reported 20 TEAEs, with the majority being mild to moderate in severity. The most commonly occurring TEAEs were thirst (45.5%), pollakiuria (36.4%) and dry mouth (27.3%). Conclusion: Tolvaptan at a daily dose of 15mg had a diuretic effect but did not increase serum sodium excretion or lead to tolvaptan accumulation. It is therefore can be safely used for short-term treatment of Chinese adult patients with confirmed Child-Pugh B cirrhosis. Clinical Trial Registration: https://clinicaltrials.gov/search?term=NCT01359462, identifier NCT01359462.

Reducing sugar intake through chronic swimming training: Exploring palatability changes and central vasopressin mechanisms

Excessive sugar intake has been associated with the onset of several non-communicable chronic diseases seen in humans. Physical activity could affect sweet taste perception which may affect sugar intake. Therefore, it was investigated the chronic effects of swimming training on sucrose intake/preference, reactivity to sucrose taste, self-care in neurobehavioral stress, and the possible involvement of the vasopressin type V1 receptor in sucrose solution intake. Male Wistar rats, of from different cohorts were used, subjected to a sedentary lifestyle (SED) or swimming training (TR - 1 h/day, 5×/week, for 8 weeks, with no added load). Weekly intake was verified in SED and TR rats after access to a sucrose solution 1×/week, 2 h/day, for eight weeks. Chronic effects of swimming and/or a sedentary lifestyle were carried out three days after the end of the physical exercise protocol. Swimming training reduced the intake of sucrose solution from the third week onwards in the two-bottle test measured once a week for 8 weeks. After the ending of the swimming protocol, sucrose intake was also reduced as per its preference. This reduced intake is probably correlated with the carbohydrate aspect of sucrose since saccharin intake was not affected. In addition, chronic swimming training was shown to reduce ingestive responses, increase neutral responses, without interfering with aversive, in the sucrose solution taste reactivity test. In addition, these results are not related to a depressive-like behavior, nor to neurobehavioral stress. Furthermore, treatment with vasopressin V1 receptor antagonist abolished the reduced sucrose intake in trained rats. The results suggest that swimming performed chronically is capable of reducing intake and preference for sucrose by decreasing the palatability of sucrose without causing depressive-type behavior or stress. In addition, the results also suggest that central V1 vasopressin receptors are part of the mechanisms activated to reduce sucrose intake in trained rats.

Immediate drop of urine osmolality upon tolvaptan initiation predicts impact on renal prognosis in patients with ADPKD.

Tolvaptan, a vasopressin V2 receptor antagonist, is used for treating autosomal dominant polycystic kidney disease (ADPKD). We focused on changes in urinary osmolality (U-Osm) after tolvaptan initiation to determine whether they were associated with the therapeutic response to tolvaptan. This was a single-centre, prospective, observational cohort study. Seventy-two patients with ADPKD who received tolvaptan were recruited. We analysed the relationship between changes in U-Osm and annual estimated glomerular filtration rate (eGFR) in terms of renal prognostic value using univariable and multivariable linear regression analyses. The mean value of U-Osm immediately before tolvaptan initiation was 351.8±142.2 mOsm/kg H2O, which decreased to 97.6±23.8 mOsm/kg H2O in the evening. The decrease in U-Osm was maintained in the outpatient clinic 1 month later. However, the 1-month values of U-Osm showed higher variability (160.2±83.8 mOsm/kg H2O) than did those in the first evening of tolvaptan administration. Multivariate analysis revealed that the baseline eGFR, baseline urinary protein and U-Osm change in the evening of the day of admission (initial U-Osm drop) were significantly correlated with the subsequent annual change in eGFR. U-Osm can be measured easily and rapidly, and U-Osm change within a short time after tolvaptan initiation may be a useful index for the renal prognosis in actual clinical practice.

Electrochemical Behavior and Determination of Tolvaptan Using Glassy Carbon and Boron-Doped Diamond Electrodes

Tolvaptan (TOL), a vasopressin V2 receptor antagonists drug, is used to treat hyponatremia in people with heart failure. Herein, we report for the first time the electrochemical behavior of TOL and its oxidation metabolite TOL-oxo on glassy carbon and boron-doped diamond electrodes (GCE, BDDE) by cyclic voltammetry (CV). For both molecules, two-electron irreversible oxidation was observed in 0.5 M H2SO4, while single-electron irreversible oxidation occurred at pH 7.0. A sensitive and rapid electroanalytical technique for the detection of TOL has been developed, based on differential pulse voltammetry (DPV). Linearity was obtained with GCE within a concentration range between 1–1000 μM, using anodic currents appearing around 1397 mV. For BDDE, the concentration range was 8–1000 μM using anodic currents around 1490 mV.

Autosomal Dominant Polycystic Kidney Disease: Is There a Role for Autophagy?

Autosomal-Dominant Polycystic Kidney Disease (ADPKD) is a monogenic disorder initiated by mutations in either PKD1 or PKD2 genes, responsible for encoding polycystin 1 and polycystin 2, respectively. These proteins are primarily located within the primary cilia. The disease follows an inexorable progression, leading most patients to severe renal failure around the age of 50, and extra-renal complications are frequent. A cure for ADPKD remains elusive, but some measures can be employed to manage symptoms and slow cyst growth. Tolvaptan, a vasopressin V2 receptor antagonist, is the only drug that has been proven to attenuate ADPKD progression. Recently, autophagy, a cellular recycling system that facilitates the breakdown and reuse of aged or damaged cellular components, has emerged as a potential contributor to the pathogenesis of ADPKD. However, the precise role of autophagy in ADPKD remains a subject of investigation, displaying a potentially twofold impact. On the one hand, impaired autophagy may promote cyst formation by inducing apoptosis, while on the other hand, excessive autophagy may lead to fibrosis through epithelial to mesenchymal transition. Promising results of autophagy inducers have been observed in preclinical studies. Clinical trials are warranted to thoroughly assess the long-term safety and efficacy of a combination of autophagy inducers with metabolic and/or aquaferetic drugs. This research aims to shed light on the complex involvement of autophagy in ADPKD, explore the regulation of autophagy in disease progression, and highlight the potential of combination therapies as a promising avenue for future investigations.

Efficacy and safety of postoperative preemptive use of tolvaptan for patients with cirrhosis undergoing hepatectomy for hepatocellular carcinoma.

Optimal choice of diuretics in perioperative management remains unclear in enhanced recovery after liver surgery. This study investigated the efficacy and safety of tolvaptan (oral vasopressin V2-receptor antagonist) in postoperative management of patients with liver injury and hepatocellular carcinoma. The patients clinically diagnosed with liver cirrhosis were included in this study. Clinical outcomes of 51 prospective cohort managed with a modified postoperative protocol using tolvaptan (validation group) were compared with 83 patients treated with a conventional management protocol (control group). Postoperative urine output were significantly larger and excessive body weight increase were reduced with no impairment in renal function or serum sodium levels in the validation group. Although the total amount of discharge and trend of serum albumin level were not significantly different among the groups, global incidence of postoperative morbidity was less frequent (19.6% vs. 44.6%, P=0.005) and postoperative stay was significantly shorter (8 days vs.10 days, P=0.008) in the validation group compared with the control group. Tolvaptan could be safely used for the patients with injured liver in postoperative management after hepatectomy and potentially advantageous in the era of enhanced recovery after surgery with its strong diuretic effect and better fluid management.

The Efficacy, the Treatment Response and the Aquaretic Effects of a Three-Year Tolvaptan Regimen in Polycystic Kidney Disease Patients.

Tolvaptan, a selective vasopressin V2 receptor antagonist, is the first and only approved specific treatment for Autosomal-Dominant Polycystic Kidney Disease (ADPKD), and is used in current clinical practice. Real clinical data are missing. In this retrospective study, 41 ADPKD patients received tolvaptan for 3 years, from 2018 to 2021. Total kidney volume (TKV) was measured using Magnetic Resonance Imaging, at initiation and at the end of the treatment period. A complete biochemistry/hematology profile and a 24 h urine volume collection were performed monthly for the first 18 months and every 3 months thereafter. At the end of the treatment period, the median (IQR) estimated Glomerular Filtration Rate (e-GFR) was 5.3 (-1.3, 8.7) mL/min higher than the expected e-GFR decline without treatment, while the prediction for End Stage Chronic Kidney Disease (ESKD) had been prolonged by 1 (0, 2) year. Total Kidney Volume did not change significantly (2250 (1357) mL at 3 years of treatment vs. 2180 (1091) mL expected without treatment, p = 0.48). Younger patients with a relatively preserved e-GFR, lower hypertension burden, better familiar renal prognosis and more severe imaging data showed better outcomes. The aquaretic adverse effects of tolvaptan did not affect renal function and electrolyte balance in 51 patients, in a follow-up period of 18 months. Consequently, tolvaptan seems to be effective in preventing progression of ADPKD when administered in a timely manner in patients with better familiar renal history, shorter hypertension duration and worse imaging profile. Increased diuresis does not affect treatment efficacy.