Efficacy and safety of two different tolvaptan doses in the treatment of hyponatremia in the Emergency Department

A retrospective study on tolvaptan prescription in clinical practice in patients with syndrome of inappropriate secretion of antidiuretic hormone (SIADH) using the Japanese claims database

We aimed to survey the status of tolvaptan administration in routine clinical practice since the approval of a novel indication for treating syndrome of inappropriate secretion of antidiuretic hormone (SIADH) in Japan. Data from a population of 3,152 patients aged ≥18 years and diagnosed with SIADH between July 1, 2020 and June 30, 2021 were extracted from a Japanese database. Tolvaptan was administered to 586 patients while 2,566 patients were followed up without tolvaptan. In the tolvaptan-treated group, the standard initial doses were 3.75 mg and 7.5 mg in 290 (49.5%) and 250 (42.7%) patients, respectively. The dose was increased in 112 (38.6%) and 71 (28.4%) and decreased in 8 (2.8%) and 46 (18.4%) of patients with 3.75 and 7.5 mg initial doses, respectively. Of the total 586 SIADH patients treated with tolvaptan, serum sodium concentrations were analyzed in 60 patients. In both treatment groups of 3.75 and 7.5 mg initial doses, the serum sodium concentration was elevated from the second day of treatment and reached 135 mEq/L on the fourth day, which was maintained for 2 weeks. Rapid correction of hyponatremia (>10 mEq/L increase in serum sodium concentration over 1 day or >18 mEq/L increase over 2 days) occurred in 26.7% patients with a 7.5 mg initial dose (4 of 15 patients) but not in the patients with a 3.75 mg initial dose (n = 16), suggesting that an initial dose of 3.75 mg of tolvaptan may be a better choice for the safe and proper correction of hyponatremia.

Long-term low-dose tolvaptan efficacy and safety in SIADH

PURPOSE

Tolvaptan, a selective vasopressin V2-receptor antagonist, is approved for the treatment of SIADH-related hyponatremia, but its use is limited. The starting dose is usually 15 mg/day, but recent clinical experience suggests a lower starting dose (<15 mg/day) to reduce the risk of sodium overcorrection. However, long-term low-dose efficacy and safety has not been explored, so far. Aim of our study is to characterize safety and efficacy of long-term SIADH treatment with low-dose Tolvaptan.

METHODS

We retrospectively evaluated 11 patients receiving low-dose Tolvaptan (<15 mg/day) for chronic SIADH due to neurological, idiopathic and neoplastic causes. Plasma sodium levels were measured before and 1, 3, 5, 15 and 30 days after starting Tolvaptan and then at 3-month intervals. Anamnestic and clinical data were collected.

RESULTS

Mean time spanned 27.3 ± 29.8 months (range 6 months-7 years). Mean plasma sodium levels were within normal range 1, 3 and 6 months after starting Tolvaptan as well as after 1, 2, 3, 5 and 7 years of therapy. Neither osmotic demyelination syndrome nor overcorrection were observed. Plasma sodium levels normalization was associated with beneficial clinical effects. Neurological patients obtained seizures disappearance, improvement in neurological picture and good recovery from rehabilitation. Neoplastic patients were able to start chemotherapy and improved their general condition. Patients did not show hypernatremia during long-term follow-up and reported mild thirst and pollakiuria.

CONCLUSIONS

The present study shows that long-term low-dose Tolvaptan is safe and effective in SIADH treatment. No cases of overcorrection were documented and mild side effects were reported.

Syndrome of Inappropriate Antidiuresis: From Pathophysiology to Management

Hyponatremia is the most common electrolyte disorder, affecting more than 15% of patients in the hospital. Syndrome of inappropriate antidiuresis (SIAD) is the most frequent cause of hypotonic hyponatremia, mediated by nonosmotic release of arginine vasopressin (AVP, previously known as antidiuretic hormone), which acts on the renal V2 receptors to promote water retention. There are a variety of underlying causes of SIAD, including malignancy, pulmonary pathology, and central nervous system pathology. In clinical practice, the etiology of hyponatremia is frequently multifactorial and the management approach may need to evolve during treatment of a single episode. It is therefore important to regularly reassess clinical status and biochemistry, while remaining alert to potential underlying etiological factors that may become more apparent during the course of treatment. In the absence of severe symptoms requiring urgent intervention, fluid restriction (FR) is widely endorsed as the first-line treatment for SIAD in current guidelines, but there is considerable controversy regarding second-line therapy in instances where FR is unsuccessful, which occurs in around half of cases. We review the epidemiology, pathophysiology, and differential diagnosis of SIAD, and summarize recent evidence for therapeutic options beyond FR, with a focus on tolvaptan, urea, and sodium-glucose cotransporter 2 inhibitors.

Safety and Efficacy of Vaptans in the Treatment of Hyponatremia from Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH): A Systematic Review and Meta-Analysis

The utilization of vasopressin receptor antagonists, known as vaptans, in the management of hyponatremia among patients afflicted with the syndrome of inappropriate antidiuretic hormone (SIADH) remains a contentious subject. This meta-analysis aimed to evaluate the safety and efficacy of vaptans for treating chronic hyponatremia in adult SIADH patients. Clinical trials and observational studies were identified by a systematic search using MEDLINE, EMBASE, and Cochrane Database from inception through September 2022. The inclusion criteria were the studies that reported vaptans' safety or efficacy outcomes compared to placebo or standard therapies. The study protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO; CRD 42022357307). Five studies were identified, comprising three RCTs and two cohort studies, enrolling a total of 1840 participants. Regarding short-term efficacy on days 4-5, vaptans exhibited a significant increase in serum sodium concentration from the baseline in comparison to the control group, with a weighted mean difference of 4.77 mmol/L (95% CI, 3.57, 5.96; I2 = 34%). In terms of safety outcomes, the pooled incidence rates of overcorrection were 13.1% (95% CI 4.3, 33.6; I2 = 92%) in the vaptans group and 3.3% (95% CI 1.6, 6.6; I2 = 27%) in the control group. Despite the higher correction rate linked to vaptans, with an OR of 5.72 (95% CI 3.38, 9.70; I2 = 0%), no cases of osmotic demyelination syndrome were observed. Our meta-analysis comprehensively summarizes the efficacy and effect size of vaptans in managing SIADH. While vaptans effectively raise the serum sodium concentration compared to placebo/fluid restriction, clinicians should exercise caution regarding the potential for overcorrection.

Tolvaptan for the treatment of the syndrome of inappropriate antidiuresis (SIAD)

The syndrome of inappropriate antidiuresis (SIAD), the commonest cause of hyponatraemia, is associated with significant morbidity and mortality. Tolvaptan, an oral vasopressin V2-receptor antagonist, leads through aquaresis to an increase in serum sodium concentration and is the only medication licenced in Europe for the treatment of euvolaemic hyponatraemia. Randomised controlled trials have shown that tolvaptan is highly efficacious in correcting SIAD-related hyponatraemia. Real-world data have confirmed the marked efficacy of tolvaptan, but they have also reported a high risk of overly rapid sodium increase in patients with a very low baseline serum sodium. The lower the baseline serum sodium, the higher the tolvaptan-induced correction rate occurs. Therefore, a lower starting tolvaptan dose of 7.5 mg has been evaluated in small cohort studies, demonstrating its efficacy, but it still remains unclear as to whether it can reduce the risk of overcorrection. Most international guidelines, except for the European ones, recommend tolvaptan as second-line treatment for SIAD after fluid restriction. However, the risk of unduly rapid sodium correction in combination with its high cost have limited its routine use. Prospective controlled studies are warranted to evaluate whether tolvaptan-related sodium increase can improve patient-related clinical outcomes, such as mortality and length of hospital stay in the acute setting or neurocognitive symptoms and quality of life in the chronic setting. In addition, the potential role of a low tolvaptan starting dose needs to be further explored. Until then, tolvaptan should mainly be used as second-line treatment for SIAD, especially when there is a clinical need for prompt restoration of normonatraemia. Tolvaptan should be used with specialist input according to a structured clinical pathway, including rigorous monitoring of electrolyte and fluid balance and, if needed, implementation of appropriate measures to prevent, or when necessary reverse, overly rapid hyponatraemia correction.

Tolvaptan versus fluid restriction in acutely hospitalised patients with moderate-profound hyponatraemia (TVFR-HypoNa): design and implementation of an open-label randomised trial

Background

Current hyponatraemia guidelines are divided on the use of tolvaptan in hospitalised patients with moderate to severe hyponatraemia, due to an uncertain risk-benefit ratio. We will conduct a randomised trial to test the hypothesis that early use of tolvaptan improves the rate of serum sodium correction and clinical outcomes compared with current standard first-line therapy, restriction of fluid intake, without increasing the risk of serum sodium overcorrection.

Methods

We will enrol hospitalised patients with euvolaemic or hypervolaemic hyponatraemia and serum sodium of 115–130 mmol/L at Austin Health, a tertiary care centre in Melbourne, Australia. Participants will be randomised 1:1 to receive either tolvaptan (initial dose 7.5 mg) or fluid restriction (initial limit 1000 ml per 24 h), with titration of therapy based on serum sodium response according to a pre-determined protocol over a 72-h intervention period.

The primary endpoint will be the between-group change in serum sodium over time, from study day 1 to day 4. Secondary endpoints include serum sodium increment in the first 24 and 48 h, proportion of participants with normalised serum sodium, length of hospital stay, requirement for serum sodium re-lowering with intravenous dextrose or desmopressin, cognitive and functional measures (Confusion Assessment Method Short form, Timed Up and Go test, hyponatraemia symptom questionnaire), 30-day readmission rate, treatment satisfaction score and serum sodium 30 days after discharge. The trial will be overseen by an independent Data Safety Monitoring Board. Serum sodium will be monitored every 6–12 h throughout the study period, with pre-specified thresholds for commencing intravenous 5% dextrose if serum sodium rise targets are exceeded.

Discussion

We seek to inform future international guidelines with high-quality data regarding the utility and safety of tolvaptan compared to standard therapy fluid restriction in patients with moderate-severe hyponatraemia in hospital. If tolvaptan use in this patient group is endorsed by our findings, we will have established an evidence-based framework for tolvaptan initiation and monitoring to guide its use.

Trial registration

Australia and New Zealand Clinical Trials Registry ACTRN12619001683123. Registered on December 2 2019

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06237-5.

Deep Learning Image Feature Recognition Algorithm for Judgment on the Rationality of Landscape Planning and Design

This paper uses an improved deep learning algorithm to judge the rationality of the design of landscape image feature recognition. The preprocessing of the image is proposed to enhance the data. The deficiencies in landscape feature extraction are further addressed based on the new model. Then, the two-stage training method of the model is used to solve the problems of long training time and convergence difficulties in deep learning. Innovative methods for zoning and segmentation training of landscape pattern features are proposed, which makes model training faster and generates more creative landscape patterns. Because of the impact of too many types of landscape elements in landscape images, traditional convolutional neural networks can no longer effectively solve this problem. On this basis, a fully convolutional neural network model is designed to perform semantic segmentation of landscape elements in landscape images. Through the method of deconvolution, the pixel-level semantic segmentation is realized. Compared with the 65% accuracy rate of the convolutional neural network, the fully convolutional neural network has an accuracy rate of 90.3% for the recognition of landscape elements. The method is effective, accurate, and intelligent for the classification of landscape element design, which better improves the accuracy of classification, greatly reduces the cost of landscape element design classification, and ensures that the technical method is feasible. This paper classifies landscape behavior based on this model for full convolutional neural network landscape images and demonstrates the effectiveness of using the model. In terms of landscape image processing, the image evaluation provides a certain basis.

Open-label, multicenter, dose-titration study to determine the efficacy and safety of tolvaptan in Japanese patients with hyponatremia secondary to syndrome of inappropriate secretion of antidiuretic hormone

The purpose of this study was to determine the efficacy and safety of tolvaptan in Japanese patients with hyponatremia secondary to syndrome of inappropriate secretion of antidiuretic hormone (SIADH). This multicenter, open-label, dose-escalation, phase III study enrolled Japanese patients (20-85 years old) with hyponatremia secondary to SIADH who were unresponsive to fluid restriction. Oral tolvaptan was administered for up to 30 days, initially at 7.5 mg/day, but escalated daily as necessary, based on the serum sodium concentration and safety, over the first 10 days until the optimal maintenance dose was determined for each patient (maximum 60 mg/day). The primary endpoint was the proportion of patients with normalized serum sodium concentration on the day after the final tolvaptan dose. Secondary endpoints included the mean change in serum sodium concentration from baseline on the day after the final dose. Sixteen patients (male, 81.3%; mean ± standard deviation age 71.9 ± 6.1 years) received tolvaptan treatment and 11 patients completed the study with one patient re-administered tolvaptan in the treatment period. Serum sodium concentrations normalized in 13 of 16 (81.3%) patients on the day after the final tolvaptan dose. The mean change in serum sodium concentration from baseline on the day after the final dose was 11.0 ± 4.3 mEq/L. Adverse events considered related to tolvaptan (10 [62.5%] patients) were generally of mild to moderate severity. Oral tolvaptan corrects hyponatremia in Japanese patients with SIADH with a similar efficacy and safety profile as that noted in non-Japanese patients.

Tolvaptan in the Management of Acute Euvolemic Hyponatremia After Transsphenoidal Surgery: A Retrospective Single-Center Analysis

INTRODUCTION

Syndrome of inappropriate antidiuresis (SIAD) can be a complication of hypothalamus-pituitary surgery. The use of tolvaptan in this setting is not well established, hence the primary aim of this study was to assess the sodium correction rates attained with tolvaptan compared with standard treatments (fluid restriction and/or hypertonic saline). Furthermore, we compared the length of hospital stay in the two treatment groups and investigated the occurrence of overcorrection and side effects including osmotic demyelination syndrome.

METHODS

We retrospectively reviewed 308 transsphenoidal surgical procedures performed between 2011 and 2019 at our hospital. We selected adult patients who developed post-operative SIAD and recorded sodium monitoring, treatment modalities and outcomes. Correction rates were adjusted based on pre-treatment sodium levels.

RESULTS

Twenty-nine patients (9.4%) developed post-operative SIAD. Tolvaptan was administered to 14 patients (median dose 15 mg). Standard treatments were employed in 14 subjects (fluid restriction n=11, hypertonic saline n=1, fluid restriction and hypertonic saline n=2). Tolvaptan yielded higher adjusted sodium correction rates (12.0 mmolL^-1/24h and 13.4 mmolL^-1/48h) than standard treatments (1.8 mmolL^-1/24h, p<0.001, and 4.5 mmolL^-1/48h, p=0.004, vs. tolvaptan). The correction rate exceeded 10 mmolL^-1/24h or 18 mmolL^-1/48h in 9/14 and 2/14 patients treated with tolvaptan, respectively, and in no patient who received standard treatments. No side effects including osmotic demyelination occurred. Tolvaptan was associated with a shorter hospital stay (11vs.15 days, p=0.01).

CONCLUSIONS

Tolvaptan is more effective than fluid restriction (with or without hypertonic saline) and allows for a shortened hospital stay in patients with SIAD after transsphenoidal surgery. However, its dose and duration should be carefully tailored, and close monitoring is recommended to allow prompt detection of overcorrection.

Hypernatremia and moderate-to-severe hyponatremia are independent predictors of mortality in septic patients at emergency department presentation: A sub-group analysis of the need-speed trial

STUDY OBJECTIVE

Early risk stratification of septic patients presenting to the emergency department (ED) is challenging. The aim of the study was to evaluate the prognostic role of plasmatic sodium level (_PNa⁺) derangements at ED presentation in septic patients.

METHODS

According to _PNa⁺ at ED presentation patients were divided in eunatremic (136-145 mEq/L), hypernatremic (>145 mEq/L) and hyponatremic (<136 mEq/L). Hyponatremic patients were subsequently divided in mild (130-135 mEq/L), moderate (125-129 mEq/L) and severe (<125 mEq/L). 7 and 30-day mortality was evaluated according to _PNa⁺ derangements and the degree of hyponatremia. The same analysis was then performed only in respiratory tract infection-related (RTI-r) sepsis patients.

RESULTS

879 septic patients were included in this analysis, 40.3% had hyponatremia, 5.7% hypernatremia. Hypernatremia showed higher mortality rates at both endpoints compared to eunatremia and hyponatremia (p<0.0001 for both). Eunatremia and mild hyponatremia were compared vs. moderate-to-severe hyponatremia showing a significant difference in terms of 7 and 30-day survival (p = 0.004 and p = 0.007, respectively). The Cox proportional model identified as independent predictors of 7 and 30-day mortality moderate-to-severe hyponatremia (HR 4.89[2.38-10.03] and 1.79[1.07-3.01], respectively) and hypernatremia (HR 3.52[1.58-7.82] and 2.14[1.17-3.92], respectively). The same analysis was performed in patients with respiratory tract infection-related sepsis (n = 549), with similar results.

CONCLUSION

Both hypernatremia and moderate-to-severe hyponatremia at ED presentation independently predict mortality in septic patients, allowing early risk stratification and suggesting more aggressive therapeutic strategies.

Management of hyponatremia associated with acute porphyria-proposal for the use of tolvaptan

Hyponatremia is a common feature during the neurovisceral acute attacks which characterize hepatic porphyrias, as well as a sign of its severity. Therapeutic options for first-line acute attacks are intravenous administration of glucose and/or exogenous heme. The former treatment can aggravate hyponatremia by dilution and cause seizures; thus, the correction of hyponatremia must be carried out with extreme caution. This review summarizes recommendations for the management of hyponatremia during acute episodes of porphyria. Hyponatremia should be corrected slowly and seizures treated with medications in order to not exacerbate motor and sensory axonal neuropathy. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is considered a frequent cause of hyponatremia in acute porphyrias and must be identified as a symptom of an acute porphyria attack. Tolvaptan produces aquaresis and is considered a safe drug in porphyria. However, its use has only been reported in isolated cases during a porphyria attack. The convenience and usefulness of this drug in acute porphyria are discussed.

Criteria for Hyponatremic Overcorrection: Systematic Review and Cohort Study of Emergently Ill Patients

BACKGROUND

Hyponatremia is the most common electrolyte disturbance amongst hospitalized patients. An overly rapid rate of correction of chronic hyponatremia is believed to increase the risk of poor clinical outcomes including osmotic demyelination syndrome (ODS). There is disagreement in the literature regarding the definition of hyponatremic overcorrection.

METHODS

We performed a systematic review of all English language studies to identify those that calculated sodium correction rate and classified patients' overcorrection status. We then identified all patients who presented to our hospital's emergency department between 2003 and 2015 with a corrected serum sodium ≤ 116 mmol/L. All methods from the systematic review for sodium correction rate calculation and overcorrection status were applied to this cohort.

RESULTS

We identified 24 studies citing 9 distinct sodium correction rate methods and 14 criteria for overcorrection. Six hundred twenty-four patients presenting with severe hyponatremia (median initial value 113 mMol) were identified. Depending on the method used, the median sodium correction rates in our cohort ranged from 0.271 to 1.13 mmol/L per hour. The proportion of patients classified with overcorrection with the different criteria varied almost 11-fold, ranging from 8.5 to 89.9%.

CONCLUSION

Published methods disagree regarding the calculation of sodium correction rates and the definition of hyponatremic overcorrection. This leads to wide variations in sodium correction rates and the prevalence of overcorrection in patient cohorts. Definitions based on ODS risk are needed.

Derivation and Validation of a Novel Risk Score to Predict Overcorrection of Severe Hyponatremia: The Severe Hyponatremia Overcorrection Risk (SHOR) Score

BACKGROUND AND OBJECTIVES

Osmotic demyelination syndrome is the most concerning complication of severe hyponatremia, occurring with an overly rapid rate of serum sodium correction. There are limited clinical tools to aid in identifying individuals at high risk of overcorrection with severe hyponatremia.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We identified all patients who presented to a tertiary-care hospital emergency department in Ottawa, Canada (catchment area 1.2 million) between January 1, 2003 and December 31, 2015, with serum sodium (corrected for glucose levels) <116 mmol/L. Overcorrection was determined using 14 published criteria. Latent class analysis measured the independent association of baseline factors with a consensus overcorrection status on the basis of the 14 criteria, and was summarized as a risk score, which was validated in two cohorts.

RESULTS

A total of 623 patients presented with severe hyponatremia (mean initial value 112 mmol/L; SD 3.2). The prevalence of no, unlikely, possible, and definite overcorrection was 72%, 4%, 10%, and 14%, respectively. Overcorrection was independently associated with decreased level of consciousness (2 points), vomiting (2 points), severe hypokalemia (1 point), hypotonic urine (4 points), volume overload (-5 points), chest tumor (-5 points), patient age (-1 point per decade, over 50 years), and initial sodium level (<110 mmol/L: 4 points; 110-111 mmol/L: 2 points; 112-113 mmol/L: 1 point). These points were summed to create the Severe Hyponatremic Overcorrection Risk (SHOR) score, which was significantly associated with overcorrection status (Spearman correlation 0.45; 95% confidence interval, 0.36 to 0.49) and was discriminating (average dichotomized c-statistic 0.77; 95% confidence interval, 0.73 to 0.81). The internal (n=119) and external (n=95) validation cohorts had significantly greater use of desmopressin, which was significantly associated with the SHOR score. The SHOR score was significantly associated with overcorrection status in the internal (P<0.001) but not external (P=0.39) validation cohort.

CONCLUSIONS

In patients presenting with severe hyponatremia, overcorrection was common and predictable using baseline information. Further external validation of the SHOR is required before generalized use.

Management of hyponatremia: causes, clinical aspects, differential diagnosis and treatment

INTRODUCTION

Hyponatremia is the most frequent electrolyte disorder in hospitalised patients. Acute and severe hyponatremia may be a life-threatening situation. However, also mild and chronic hyponatremia may negatively affect the health status (i.e. gait disturbances, attention deficits, falls and fractures, and bone loss) and may increase the risk of death. Therefore, it is of paramount importance for clinicians to have an in-depth knowledge on this topic, in order to appropriately manage patients affected by hyponatremia.

AREAS COVERED

This review will cover different areas related to this electrolyte disorder. Because many pathologic conditions may be associated with hyponatremia, thorough investigations have to be performed in order to establish the underlying etiology. To establish the cause of hyponatremia is of great importance, because an appropriate therapeutic strategy is strictly dependent on a correct diagnosis. A description of the different available therapeutic approaches for the correction of hyponatremia, including vaptans, will follow.

EXPERT COMMENTARY

Undoubtedly, the studies that have been published in recent years and the introduction of vaptans in clinical practice have contributed to increase the awareness on hyponatremia among clinicians. Nevertheless, additional studies are needed in order to clarify some partially uncovered areas.

Safety and Efficacy of Tolvaptan in Korean Patients with Hyponatremia Caused by the Syndrome of Inappropriate Antidiuretic Hormone

BACKGROUND

The aim of this multicenter study was to evaluate the safety and efficacy of tolvaptan (TLV) in Korean patients with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH).

METHODS

Of 51 enrolled patients with SIADH, 39 patients (16 female patients, aged 70.8 ± 11.3 years) were included in an intention to treat analysis. All patients received 15 mg/day as the initial dose, and the dose was then increased up to 60 mg/day (as needed) until day 4.

RESULTS

Serum sodium increased significantly from baseline during the first 24 hours (126.8 ± 4.3 vs. 133.7 ± 3.8 mmol/L, P < 0.001), rose gradually between days 1 and 4 (133.7 ± 3.8 vs. 135.6 ± 3.6 mmol/L, P < 0.05), and then plateaued until day 11 (136.7 ± 4.5 mmol/L). The correlation between the change in serum sodium for the first 24 hours and initial serum sodium concentration was significant (r = -0.602, P < 0.001). In severe hyponatremia (< 125 mmol/L), the change was significantly higher (11.1 ± 4.8 mmol/L) than in moderate (6.4 ± 2.5 mmol/L, P < 0.05) or mild hyponatremia (4.3 ± 3.3 mmol/L, P < 0.01). In addition, logistic regression analysis showed that body weight (odds ratio [OR], 0.858; 95% confidence interval [CI], 0.775-0.976; P = 0.020) and body mass index (BMI) (OR, 0.692; 95% CI, 0.500-0.956; P = 0.026) were associated with rapid correction. No serious adverse events were reported, but in 13% of patients hyponatremia was overcorrected.

CONCLUSION

TLV is effective in correcting hyponatremia and well-tolerated in Korean patients with SIADH. However, those with low body weight, low BMI or severe hyponatremia, could be vulnerable to overcorrection with the initial dose of 15 mg TLV.

The Outcome of Cirrhotic Patients with Ascites Is Improved by the Normalization of the Serum Sodium Level by Tolvaptan

Objective Hyponatremia is frequently observed in patients with decompensated liver cirrhosis and it is also related to a poor prognosis. The vasopressin V2-receptor antagonist tolvaptan is used to treat cirrhotic patients with ascites and increases the serum sodium (Na) level. In this study, we investigated (i) whether or not correction of the Na level improves the prognosis of cirrhotic patients with ascites and (ii) predictors of normalization of the serum Na level after tolvaptan therapy. Methods This was a single-center retrospective study. A total of 95 Japanese cirrhotic patients (60 men, median age 63 years) were enrolled and received tolvaptan orally after hospitalization for ascites treatment. The serum Na level was monitored during the period of tolvaptan treatment. The laboratory data and survival rates of patients who achieved serum Na levels of <135 and ≥135 mEq/L after 1 week were compared. Results Patients showed serum Na levels of 136 (121-145) mEq/L, and 42.1% had a serum Na level of <135 mEq/L. Among patients with an initial serum Na level <135 mEq/L, 60.0% achieved a normal level after 1 week, and the survival rate was significantly higher in patients with a normalized serum Na level (p<0.01). The pretreatment brain natriuretic peptide (BNP) level was predictive of achieving a serum Na level of ≥135 mEq/L (odds ratio: 0.87, 95% confidence interval: 0.316-0.987, p<0.05). Conclusion Normalization of the Na level after one week was associated with a favorable outcome of tolvaptan therapy, and Na correction improved the prognosis.