Acute Kidney Injury Due to Nephrolithiasis in Autosomal Dominant Polycystic Kidney Disease Treated With Tolvaptan: A Case Report.

A 61-year-old asymptomatic female with autosomal dominant polycystic kidney disease (ADPKD) on tolvaptan therapy was hospitalized for acute kidney injury (AKI). Nephrolithiasis had already been diagnosed; however, the patient had not undergone any interventions. She also presented with hyponatremia possibly caused by overhydration. Because the estimated glomerular filtration rate (eGFR) decline was significantly higher than the predicted rate, we considered a possible case of postrenal AKI and examined computed tomography (CT), which revealed left hydronephrosis with a 9.4-mm ureteric stone at the level of L3/L4. We restricted fluid intake, which resulted in an increase in sodium levels. She was treated with transurethral lithotripsy (TUL) twice, which successfully improved her kidney function. Although the serum sodium levels increase because of aquaresis in almost all patients treated with tolvaptan, our case was unique in that the patient presented with hyponatremia. We should pay more attention to the periodical follow-up of nephrolithiasis in addition to the increase in total kidney volume and decide the appropriate time to treat nephrolithiasis depending on the case. We should also keep in mind that ADPKD patients have a high frequency of nephrolithiasis and, even if asymptomatic, investigate urinary tract obstruction and hydronephrosis in case of AKI.

Structural basis of tolvaptan binding to the vasopressin V2 receptor.

The vasopressin V2 receptor (V2R) is a validated therapeutic target for autosomal dominant polycystic kidney disease (ADPKD), with tolvaptan being the first FDA-approved antagonist. Herein, we used Gaussian accelerated molecular dynamics simulations to investigate the spontaneous binding of tolvaptan to both active and inactive V2R conformations at the atomic-level. Overall, the binding process consists of two stages. Tolvaptan binds initially to extracellular loops 2 and 3 (ECL2/3) before overcoming an energy barrier to enter the pocket. Our simulations result highlighted key residues (e.g., R181, Y205, F287, F178) involved in this process, which were experimentally confirmed by site-directed mutagenesis. This work provides structural insights into tolvaptan-V2R interactions, potentially aiding the design of novel antagonists for V2R and other G protein-coupled receptors.

QbD green analytical procedure for the quantification of tolvaptan by utilizing stability indicating UHPLC method.

For the first time a new QbD-assisted green stability indicating ultra-high-performance liquid chromatography (UHPLC) method was developed and validated for quantifying Tolvaptan. The method is simple, quick, cost-effective, and stable, and it was used to formulate a quality target product profile (QTPP) with strategically defined critical analytical attributes (CAAs) to meet specific criteria. Chromatographic separation was undertaken using a 10 cm long column of ACE excel super C18 with an interior diameter of 2.1 mm and particle size of 1.7 µm. The analysis was performed under controlled conditions at 25 ℃ with the mobile phase flowing at a rate of 0.2 mL/min and detection occurring at 220 nm. Injected 3 µL of standard by using an isocratic mobile phase system consisting of acetonitrile and water in a 95:5 v/v ratio. The diluents, prepared by mixing acetonitrile with water at a 90:10 volumetric ratio, were utilized. The analyte's retention time was determined to be 1.63 min. The developed method provided reliable results with accuracy exceeding 99% and a correlation coefficient exceeding 0.999 ranged between 10 and 150 µg/mL across the range for LOQ-150% levels. Notably, during forced degradation testing, Tolvaptan exhibited susceptibility to acidic hydrolysis. The method effectively separated degradation products during stress testing, demonstrating its stability-indicating status. Environmental sustainability assessment of the developed method was conducted through the investigation of various indicators of Complex GAPI, Analytical Eco scale and Analytical GREEness and it was concluded the optimized method aligns with environmentally friendly practices.

Development, validation and application of a UPLC-MS/MS method for simultaneous quantification of OPC-61815 and its metabolites tolvaptan, DM-4103 and DM-4107 in human plasma.

OPC-61815 is an intravenous formulation vasopressin antagonist designed to treat heart failure patients, especially who have difficulty in oral intake. Tolvaptan together with DM-4103 and DM-4107 are considered as the major metabolites of OPC-61815 biotransformed in the liver via cytochrome P450 (CYP) 3A. An efficient and robust ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for quantification of OPC-61815 and its three metabolites in human plasma was developed and fully validated. To our best knowledge, it was the first published method that simultaneously quantified all of these four analytes in only one run. Simple and rapid sample preparation procedure and very short UPLC-MS/MS run time (3.5 min) offered OPC-61815 and its metabolites relatively high throughput detection, which was greatly beneficial to further clinical bio-sample analysis. The method showed good linearity and sufficient sensitivity in the range of 2.00-1000 ng/mL with a low limit of quantitation (2.00 ng/mL) for each analyte. For samples with concentrations above 1000 ng/mL, 100-fold dilution with blank plasma before sample preparation was accepted. High precision and accuracy, high selectivity and satisfactory recovery of this method were demonstrated. For all of the four analytes, no significant matrix effect or carry-over was observed. The stability of analytes and internal standards under different conditions were evaluated to ensure they were stable during the whole period of storage, preparation and detection. Also, re-injection reproducibility was investigated. In addition, the conversion test showed that almost no OPC-61815 converted into DM-4103 and DM-4107 during sample processing, while attention should be paid to the concentration difference between OPC-61815 and tolvaptan in bioanalysis. The developed UPLC-MS/MS method was successfully applied to an open, single and multiple dose administration phase I trial for monitoring the pharmacokinetics of OPC-61815. This work provided a promising way for further pharmacokinetic study of OPC-61815.

The role of tolvaptan add-on therapy in patients with acute heart failure: a systematic review and network meta-analysis.

Background: Several conflicting reviews have concluded that the use of loop diuretics is associated with poorer clinical and safety outcomes. Therefore, this study aimed to investigate the efficacy and safety of tolvaptan as an adjunct to conventional diuretic therapy in patients with acute heart failure (AHF). Methods: A comprehensive search was conducted on PubMed, Embase, ProQuest, EBSCO, and Cochrane Library until 24 May 2023 to identify randomized controlled trials that compared the effects of tolvaptan with conventional therapy and placebo in patients with AHF. The quality assessment of the included trials was conducted using the Cochrane risk of bias. A network meta-analysis (NMA) was conducted to examine the dosage effect of tolvaptan. Result: A total of 17 studies with 18 reports, involving 10,039 patients, were selected. The tolvaptan add-on therapy significantly alleviated dyspnea [24 h: RR 1.16 (1.04, 1.29), 48 h: RR 1.18 (1.04, 1.33)], reduced body weight within 48 h [Asian group, MD -0.93 (-1.48, -0.38); non-Asian group, MD -2.76 (-2.88, -2.65)], reduced edema [RR 1.08 (1.02, 1.15)], increased serum sodium [non-Asian group, MD 3.40 (3.02, 3.78)], and resulted in a change in serum creatinine [MD -0.10 (-0.18, -0.01)]. No significant differences were observed in mortality and rehospitalization. The NMA suggested that an intermediate dosage (15 mg/day) might offer the best efficacy in reducing dyspnea within 24 h, reducing edema, increasing serum sodium, and lowering the incidence of worsening renal function (WRF). Conclusion: In conclusion, the meta-analysis showed that tolvaptan contributed to the short-term alleviation of congestive symptoms, elevated sodium levels, and a lower incidence of WRF. However, no significant benefits were observed in long-term symptoms, rehospitalization rates, and mortality. An intermediate dosage of tolvaptan might be considered the optimal choice for various clinical outcomes. Systematic Review Registration: https://www.crd.york.ac.uk/, PROSPERO (CRD42023420288).

Juxtaglomerular apparatus-mediated homeostatic mechanisms: therapeutic implication for chronic kidney disease.

INTRODUCTION: Juxtaglomerular apparatus (JGA)-mediated homeostatic mechanism links to how sodium-glucose cotransporter 2 inhibitors (SGLT2is) slow progression of chronic kidney disease (CKD) and may link to how tolvaptan slows renal function decline in autosomal dominant polycystic kidney disease (ADPKD). AREA COVERED: JGA-mediated homeostatic mechanism has been hypothesized based on investigations of tubuloglomerular feedback and renin-angiotensin system. We reviewed clinical trials of SGLT2is and tolvaptan to assess the relationship between this mechanism and these drugs. EXPERT OPINION: When sodium load to macula densa (MD) increases, MD increases adenosine production, constricting afferent arteriole (Af-art) and protecting glomeruli. Concurrently, MD signaling suppresses renin secretion, increases urinary sodium excretion, and counterbalances reduced sodium filtration. However, when there is marked increase in sodium load per-nephron, as in advanced CKD, MD adenosine production increases, relaxing Af-art and maintaining sodium homeostasis at the expense of glomeruli. The beneficial effects of tolvaptan on renal function in ADPKD may also depend on the JGA-mediated homeostatic mechanisms since tolvaptan inhibits sodium reabsorption in the thick ascending limb.The JGA-mediated homeostatic mechanism regulates Af-arts, constricting to relaxing according to homeostatic needs. Understanding this mechanism may contribute to the development of pharmacotherapeutic compounds and better care for patients with CKD.

An Electronic Health Record-Integrated Application for Standardizing Care and Monitoring Patients With Autosomal Dominant Polycystic Kidney Disease Enrolled in a Tolvaptan Clinic: Design and Implementation Study.

Background: Tolvaptan is the only US Food and Drug Administration-approved drug to slow the progression of autosomal dominant polycystic kidney disease (ADPKD), but it requires strict clinical monitoring due to potential serious adverse events. Objective: We aimed to share our experience in developing and implementing an electronic health record (EHR)-based application to monitor patients with ADPKD who were initiated on tolvaptan. Methods: The application was developed in collaboration with clinical informatics professionals based on our clinical protocol with frequent laboratory test monitoring to detect early drug-related toxicity. The application streamlined the clinical workflow and enabled our nursing team to take appropriate actions in real time to prevent drug-related serious adverse events. We retrospectively analyzed the characteristics of the enrolled patients. Results: As of September 2022, a total of 214 patients were enrolled in the tolvaptan program across all Mayo Clinic sites. Of these, 126 were enrolled in the Tolvaptan Monitoring Registry application and 88 in the Past Tolvaptan Patients application. The mean age at enrollment was 43.1 (SD 9.9) years. A total of 20 (9.3%) patients developed liver toxicity, but only 5 (2.3%) had to discontinue the drug. The 2 EHR-based applications allowed consolidation of all necessary patient information and real-time data management at the individual or population level. This approach facilitated efficient staff workflow, monitoring of drug-related adverse events, and timely prescription renewal. Conclusions: Our study highlights the feasibility of integrating digital applications into the EHR workflow to facilitate efficient and safe care delivery for patients enrolled in a tolvaptan program. This workflow needs further validation but could be extended to other health care systems managing chronic diseases requiring drug monitoring.

Measured and Estimated Glomerular Filtration Rate to Evaluate Rapid Progression and Changes over Time in Autosomal Polycystic Kidney Disease: Potential Impact on Therapeutic Decision-Making.

Autosomal polycystic kidney disease (ADPKD) is the most common genetic form of kidney failure, reflecting unmet needs in management. Prescription of the only approved treatment (tolvaptan) is limited to persons with rapidly progressing ADPKD. Rapid progression may be diagnosed by assessing glomerular filtration rate (GFR) decline, usually estimated (eGFR) from equations based on serum creatinine (eGFRcr) or cystatin-C (eGFRcys). We have assessed the concordance between eGFR decline and identification of rapid progression (rapid eGFR loss), and measured GFR (mGFR) declines (rapid mGFR loss) using iohexol clearance in 140 adults with ADPKD with ≥3 mGFR and eGFRcr assessments, of which 97 also had eGFRcys assessments. The agreement between mGFR and eGFR decline was poor: mean concordance correlation coefficients (CCCs) between the method declines were low (0.661, range 0.628 to 0.713), and Bland and Altman limits of agreement between eGFR and mGFR declines were wide. CCC was lower for eGFRcys. From a practical point of view, creatinine-based formulas failed to detect rapid mGFR loss (-3 mL/min/y or faster) in around 37% of the cases. Moreover, formulas falsely indicated around 40% of the cases with moderate or stable decline as rapid progressors. The reliability of formulas in detecting real mGFR decline was lower in the non-rapid-progressors group with respect to that in rapid-progressor patients. The performance of eGFRcys and eGFRcr-cys equations was even worse. In conclusion, eGFR decline may misrepresent mGFR decline in ADPKD in a significant percentage of patients, potentially misclassifying them as progressors or non-progressors and impacting decisions of initiation of tolvaptan therapy.

Prospective Study on Individualized Dose Adjustment of Tolvaptan Based on Urinary Osmolality in Patients With ADPKD.

Introduction: Tolvaptan has been shown to reduce renal volume and delay disease progression in autosomal-dominant polycystic kidney disease (ADPKD). However, no biomarkers are currently available to guide dose adjustment. We aimed to explore the possibility of individualized tolvaptan dose adjustments based on cut-off values for urinary osmolality (OsmU). Methods: This prospective cohort study included patients with ADPKD, with rapid disease progression. Tolvaptan treatment was initiated at a dose of 45/15 mg and increased based on OsmU, with a limit set at 200 mOsm/kg. Primary renal events (25% decrease in estimated glomerular filtration rate [eGFR] during treatment), within-patient eGFR slope, and side effects were monitored during the 3-year follow-up. Results: Forty patients participated in the study. OsmU remained below 200 mOsm/kg throughout the study period, and most patients required the minimum tolvaptan dose (mean dose, 64 [±10] mg), with a low discontinuation rate (5%). The mean annual decline in eGFR was -3.05 (±2.41) ml/min per 1.73 m2 during tolvaptan treatment, compared to the period preceding treatment, corresponding to a reduction in eGFR decline of more than 50%. Primary renal events occurred in 20% of patients (mean time to onset, 31 months; 95% confidence interval [CI] = 28-34). Conclusion: Individualized tolvaptan dose adjustment based on OsmU in patients with ADPKD and rapid disease progression provided benefits in terms of reducing eGFR decline, compared with reference studies, and displayed lower dropout rates and fewer side effects. Further studies are required to confirm optimal strategies for the use of OsmU for tolvaptan dose adjustment in patients with ADPKD.

Case report: Secondary failure to tolvaptan in a patient with SCLC and paraneoplastic SIADH.

The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is frequent in lung cancer patients. Here, we report a case with persistent hyponatremia, which suggested malignant SIADH and facilitated an early diagnosis of small cell lung cancer (SCLC). A combined radio-chemotherapy led to a partial remission and resolution of SIADH. An early relapse was indicated by reoccurring severe hyponatremia and increased copeptin levels, which were used as surrogate markers for the antidiuretic hormone (ADH). As palliative immunochemotherapy, together with fluid restriction and solute substitution, were unable to control hyponatremia, treatment with the ADH V2-receptor antagonist tolvaptan was initiated. Over time, the dose of tolvaptan needed to be increased, paralleled by a well-documented exponential increase of copeptin levels. In summary and conclusion, this is a rare case of a secondary failure to tolvaptan with unique documentary evidence of increasing copeptin levels. This observation supports the hypothesis that exceedingly high ADH levels may lead to competitive displacement of tolvaptan from the V2 receptor.

Clinical efficacy of tolvaptan in acute decompensated heart failure patients with severe aortic stenosis and atrial fibrillation: a sub-analysis from the LOHAS registry.

BACKGROUND: Severe aortic valve stenosis (AS) and atrial fibrillation (AF) are risk factors of hemodynamic instability in heart failure (HF) management due to low cardiac output, respectively. Therefore, the treatment of HF due to severe AS complicated with AF is anticipated to be difficult. Tolvaptan, a vasopressin V2 receptor inhibitor, is effective in controlling acute decompensated heart failure (ADHF) with hemodynamic stability. However, its clinical efficacy against ADHF caused by AS with AF remains to be determined. METHODS: Clinical information (from September 2014 to December 2017) of 59 patients diagnosed with ADHF due to severe AS (20 patients with AF; 39 patients with sinus rhythm [SR]) was obtained from the LOHAS registry. The registry collected data from seven hospitals and assessed the short-term effects of tolvaptan in patients hospitalized for ADHF with severe AS. We attempted to identify clinical differences from baseline up to 4 days, comparing patients with AF (AF group) versus those with SR (SR group). RESULTS: There were no significant differences between the groups in age (83.7 ± 4.5 vs. 85.8 ± 6.9 years, respectively; p = 0.11) and aortic valve area (0.60 [0.46-0.73] vs. 0.56 [0.37-0.70] cm2, respectively; p = 0.50). However, left atrial volume was larger (104 [85-126] vs. 87 [64-103] mL, respectively; p < 0.01), whereas stroke volume was lower (51.6 ± 14.8 vs. 59.0 ± 18.7 mL, respectively; p = 0.08) in the AF group versus the SR group. Body weight decreased daily from baseline up to day 4 in both groups (from 55.4 to 53.2 kg [p < 0.01] and from 53.5 to 51.0 kg [p < 0.01], respectively) without change in heart rate. Notably, the systolic blood pressure decreased slightly in the AF group after 2 days of treatment with tolvaptan. CONCLUSIONS: Short-term treatment with tolvaptan improved HF in patients hospitalized for severe AS, regardless of the presence of AF or SR. After achieving sufficient diuresis, a slight decrease in blood pressure was observed in the AF group, suggesting an appropriate timeframe for safe and effective use of tolvaptan.

Long-term effectiveness and safety of tolvaptan in autosomal dominant polycystic kidney disease.

BACKGROUND AND OBJECTIVES: Evidence on the long-term use of tolvaptan in autosomal dominant polycystic kidney disease (ADPKD) is limited. The aim was to evaluate the tolvaptan effectiveness and safety in real clinical setting. MATERIAL AND METHODS: A single-center observational study (2016-2022) involving ADPKD patients treated with tolvaptan was conducted. Annual change in serum creatinine (sCr) and estimated glomerular filtration rate (eGFR) before and after treatment initiation were evaluated. Change in total kidney volume (TKV), blood pressure (BP) and urinary albuminuria at 12, 24 and 36 months after initiation were also determined. Adverse events (AEs) according to the Common Terminology Criteria for Adverse Events (CTCAE) v5.0 were analyzed. RESULTS: A total of 22 patients were included. No significant differences pre- vs post tolvaptan treatment in annual rate of change in eGFR (-3.52ml/min/1.73m2 [-4.98%] vs -3.98ml/min/1.73m2 [-8.48%], p=0.121) and sCr (+0.06mg/dL [4.22%] vs +0.15mg/dL [7.77%], p=0.429) were observed. Tolvaptan improved urinary osmolality at 12 (p=0.019) and 24 months (p=0.008), but not at 36 months (p=0.11). There were no changes in TKV, BP control and urinary albuminuria at 12, 24 or 36 months. A worse response was shown in patients with rapid kidney function decline (p=0.042). A 36.4% of the patients developed grade III/IV AEs. A 22.7% discontinued treatment due to unacceptable toxicity. CONCLUSIONS: This study shows a modest benefit of tolvaptan in ADPKD patients, as well as safety concerns.

Treatment for patients with autosomal dominant polycystic kidney disease in the chronic kidney disease without kidney replacement therapy in real-world clinical practice: a descriptive retrospective cohort study.

BACKGROUND: In real-world clinical practice, treatments selected for patients with autosomal dominant polycystic kidney disease (ADPKD) in the chronic kidney disease (CKD) without kidney replacement therapy (KRT) have not been reported. This study investigated the oral treatments used in these patients and the changes in their use in recent years. Additionally, we studied the factors affecting tolvaptan dose reduction or discontinuation. METHODS: This retrospective cohort study was conducted using the medical records of 160 hospitals in Japan. Patients with ADPKD or polycystic kidney disease registered on the database between January 2014 and December 2020 were selected. Changes in prescription proportions over time were assessed using the Cochran-Armitage test. We focused on patients prescribed with >15 mg of tolvaptan daily to identify the factors related to its dose reduction or discontinuation and used Multivariate Cox regression analysis to evaluate them. RESULTS: Tolvaptan use in patients with ADPKD in the CKD without KRT stage has increased. As of 2020, 25% of patients were treated with tolvaptan. Overall, 3639 patients with ADPKD were enrolled in the database, of whom 156 were treated with tolvaptan. Of these, 64 patients (41%) reduced or discontinued tolvaptan during the observation period. The presence of an estimated glomerular filtration rate <60 mL/min/1.73 m2 at the beginning of the treatment was associated with a higher risk of tolvaptan dose reduction or discontinuation. CONCLUSION: The proportion of patients with ADPKD treated with high-dose tolvaptan is increasing. However, patients with late-stage CKD tended to reduce or discontinue tolvaptan.

Comparative Safety and Effectiveness of Urea and Tolvaptan for the Management of Hyponatremia.

Background: The optimal management of euvolemic and hypervolemic hyponatremia remains controversial. The effectiveness of the vasopressin receptor antagonist tolvaptan on serum sodium normalization has been well described in the literature, although the associated risk of serum sodium overcorrection limits its use. Urea has been proposed as an alternative treatment option due to its milder serum sodium raising effects and adverse event profile. Objective: This study aimed to compare urea and tolvaptan for their serum sodium raising effects and potential for overcorrection. Methods: In a multicenter retrospective review, 46 hospitalized patients who received either urea or tolvaptan for the management of hyponatremia were evaluated for the rate of serum sodium normalization and overcorrection. Results: Mean serum sodium concentrations at baseline were 125.91 mEq/L and 123.83 mEq/L for patients treated with urea and tolvaptan, respectively. After 12 hours, tolvaptan was associated with a significantly higher rate of serum sodium increase compared with urea (5.05 mEq/L vs 1.10 mEq/L; P = .001). However, no statistically significant differences were observed in the mean change in serum sodium concentrations at 24 hours, 48 hours, or with the proportion of patients who reached a serum sodium concentration of 135 mEq/L. Overcorrection rates were significantly higher with tolvaptan compared with urea at 43% and 9%, respectively. Conclusion: The results of this study suggest that urea has a comparable effectiveness profile to tolvaptan for the management of hyponatremia with a significantly reduced risk of overcorrection.

Renal ultrasonography predicts worsening renal function in patients with heart failure under tolvaptan administration.

AIMS: Renal dysfunction in patients with chronic heart failure predicts a poor prognosis. Tolvaptan has a diuretic effect in patients with chronic kidney disease and heart failure without adverse effects on renal function. We aimed to determine the effects of tolvaptan and predictors of worsening renal function in patients with heart failure. METHODS AND RESULTS: This post hoc analysis was a sub-analysis of a single-centre prospectively randomized trial on the early and short-term tolvaptan administration. We enrolled 201 participants with decompensated heart failure between January 2014 and March 2019 (early group, n = 104; age: 79.0 ± 12.8 years; late group, n = 97; age: 80.3 ± 10.8 years). Renal ultrasonography was performed before and after the administration of tolvaptan. Urine output and oral water intake significantly increased during tolvaptan administration. The difference between water intake and urine volume increased during tolvaptan administration. Changes in body weight, blood pressure, heart rate, and estimated glomerular filtration rate (eGFR) in both groups were comparable. The changes in peak-systolic velocity (PSV), acceleration time (AT) of the renal arteries, and resistance index were comparable. The changes in PSV and end-diastolic velocity (EDV) of the interlobar arteries increased following tolvaptan administration (Δmax PSV: 0.0 ± 14.8 cm/s before tolvaptan vs. 5.6 ± 15.7 cm/s after tolvaptan, P = 0.002; Δmean PSV: 0.4 ± 12.3 vs. 4.9 ± 12.7 cm/s, P = 0.002; Δmax EDV: -0.2 ± 3.5 vs. 1.4 ± 4.0 cm/s, P = 0.001; Δmean EDV: -0.0 ± 3.1 vs. 1.1 ± 3.4 cm/s, P = 0.003). The renal artery AT was negatively correlated with the eGFR (Δmax AT: beta = -0.2354, P = 0.044; Δmean AT: beta = -0.2477, P = 0.035). CONCLUSIONS: Tolvaptan increased the PSV and EDV of the interlobar artery, which may mean tolvaptan increased renal blood flow. The renal artery AT may be a surrogate for worsening renal function.

The screening, diagnosis, and management of patients with autosomal dominant polycystic kidney disease: A national consensus statement from Taiwan.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited cause of end-stage kidney disease (ESKD) worldwide. Guidelines for the diagnosis and management of ADPKD in Taiwan remains unavailable. In this consensus statement, we summarize updated information on clinical features of international and domestic patients with ADPKD, followed by suggestions for optimal diagnosis and care in Taiwan. Specifically, counselling for at-risk minors and reproductive issues can be important, including ethical dilemmas surrounding prenatal diagnosis and pre-implantation genetic diagnosis. Studies reveal that ADPKD typically remains asymptomatic until the fourth decade of life, with symptoms resulting from cystic expansion with visceral compression, or rupture. The diagnosis can be made based on a detailed family history, followed by imaging studies (ultrasound, computed tomography, or magnetic resonance imaging). Genetic testing is reserved for atypical cases mostly. Common tools for prognosis prediction include total kidney volume, Mayo classification and PROPKD/genetic score. Screening and management of complications such as hypertension, proteinuria, urological infections, intracranial aneurysms, are also crucial for improving outcome. We suggest that the optimal management strategies of patients with ADPKD include general medical care, dietary recommendations and ADPKD-specific treatments. Key points include rigorous blood pressure control, dietary sodium restriction and Tolvaptan use, whereas the evidence for somatostatin analogues and mammalian target of rapamycin (mTOR) inhibitors remains limited. In summary, we outline an individualized care plan emphasizing careful monitoring of disease progression and highlight the need for shared decision-making among these patients.

Additional renoprotective effect of the SGLT2 inhibitor dapagliflozin in a patient with ADPKD receiving tolvaptan treatment.

Autosomal dominant polycystic kidney disease (ADPKD) is a major cause of end-stage kidney disease (ESKD). Vasopressin plays a pivotal role in ADPKD progression; therefore, the selective vasopressin V2 receptor antagonist tolvaptan is used as a key drug in the management of ADPKD. On the other hand, sodium-glucose cotransporter-2 inhibitors (SGLT2i), which may possibly stimulate vasopressin secretion due to the diuretic effect of the drug, have been shown to have both renal and cardioprotective effects in various populations, including those with non-diabetic chronic kidney disease. However, the effect of SGLT2i in patients with ADPKD have not been fully elucidated. Herein, we report the case of a patient with ADPKD on tolvaptan who was administered the SGLT2i dapagliflozin. The patient was a Japanese woman diagnosed with ADPKD at age 30. Despite the treatment with tolvaptan, eGFR was gradually declined from 79.8 to 50 ml/min/1.73 m2 in almost 5 years and 10 mg of dapagliflozin was initiated in the hope of renoprotective effects. Although a small increase in vasopressin levels was observed, eGFR decline rate was moderated after dapagliflozin initiation. This case suggested an additional renoprotective effect of dapagliflozin in patient with ADPKD receiving tolvaptan. Although there is no evidence about the renal protective effect of SGLT2i in patients with ADPKD, we hereby report a case successfully treated with dapagliflozin for approximately 2 years. Further research, including clinical trials, is needed to evaluate whether SGLT2i are effective in patients with ADPKD.

Protocol to evaluate the efficacy and safety of tolvaptan in patients with refractory ascites after liver resection: an open-label, single-arm phase I/II study.

Background: In patients with chronic liver diseases such as cirrhosis, massive ascites after hepatic resection is the cause of prolonged hospitalization and worsening prognosis. Recently, the efficacy of tolvaptan in refractory ascites has been reported; however, there are no reports on the efficacy or safety of tolvaptan for refractory ascites after hepatic resection. This study aims to evaluate the efficacy of early administration of tolvaptan in patients with refractory ascites after hepatic resection. Materials and methods: This is an open-label, single-arm phase I/II study. This study subject will comprise patients scheduled for hepatic resection of a liver tumor. Patients with refractory ascites after hepatic resection (drainage volume on postoperative day 1 ≥5 ml/body weight 1 kg/day) will be treated with tolvaptan. The primary endpoint will include the maximum change in body weight after hepatic resection relative to the preoperative baseline. The secondary endpoints will include drainage volume, abdominal circumference, urine output, postoperative complication rate (heart failure and respiratory failure), number of days required for postoperative weight gain because of ascites to decrease to preoperative weight, change in improvement of postoperative pleural effusion, total amount of albumin or fresh frozen plasma transfusion, type and amount of diuretics used, and postoperative hospitalization days. Conclusion: This trial will evaluate the efficacy and safety of tolvaptan prophylaxis for refractory ascites after hepatic resection. As there are no reports demonstrating the efficacy of tolvaptan prophylaxis for refractory ascites after hepatic resection, the authors expect that these findings will lead to future phase III trials and provide valuable indications for the selection of treatments for refractory postoperative ascites.

Evaluation of the Renal and Cardiovascular Effects of Long-Term Tolvaptan Treatment in Autosomal Dominant Polycystic Kidney Disease.

INTRODUCTION: Cardiovascular diseases constitute a significant cause of morbidity and mortality in individuals with autosomal dominant polycystic kidney disease (ADPKD). This study aimed to assess the long-term effects of tolvaptan on the kidneys and heart in rapidly progressing ADPKD. METHODS: Among 354 patients diagnosed with ADPKD, 58 meeting the eligibility criteria for tolvaptan were included in the study. The study comprised two groups with similar demographic and clinical characteristics: 29 patients receiving tolvaptan treatment and 29 in the control group. Several included genetic analysis, magnetic resonance imaging, and echocardiography. Clinical and cardiac changes were recorded in both groups after a 3-year follow-up. RESULTS: Tolvaptan treatment demonstrated a significant reduction in the rate of eGFR decline compared to the control group. Furthermore, it was observed that tolvaptan could prevent the development of cardiac arrhythmias by inhibiting an increase in QTc interval and heart rate. CONCLUSION: These findings suggest that, in addition to slowing kidney progression in ADPKD management, tolvaptan may potentially benefit in preventing cardiac complications.

Diuretic Treatment in Patients with Heart Failure: Current Evidence and Future Directions-Part II: Combination Therapy.

PURPOSE OF REVIEW: Fluid retention or congestion is a major cause of symptoms, poor quality of life, and adverse outcome in patients with heart failure (HF). Despite advances in disease-modifying therapy, the mainstay of treatment for congestion-loop diuretics-has remained largely unchanged for 50 years. In these two articles (part I: loop diuretics and part II: combination therapy), we will review the history of diuretic treatment and current trial evidence for different diuretic strategies and explore potential future directions of research. RECENT FINDINGS: We will assess recent trials, including DOSE, TRANSFORM, ADVOR, CLOROTIC, OSPREY-AHF, and PUSH-AHF, and assess how these may influence current practice and future research. There are few data on which to base diuretic therapy in clinical practice. The most robust evidence is for high-dose loop diuretic treatment over low-dose treatment for patients admitted to hospital with HF, yet this is not reflected in guidelines. There is an urgent need for more and better research on different diuretic strategies in patients with HF.