Public support for patients with intractable diseases in Japan: impact on clinical indicators from nationwide registries in patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Clinical practice guidelines recommend antihypertensive and tolvaptan therapies for patients with autosomal dominant polycystic kidney disease (ADPKD) in Japan. However, tolvaptan therapy may pose an economic burden. The Japanese Ministry of Health, Labour and Welfare supports patients with intractable diseases. This study aimed to confirm the impact of the intractable disease system in Japan on the clinical treatment of ADPKD. METHODS: We analyzed the data of 3768 patients with ADPKD having a medical subsidy certificate from the Japanese Ministry of Health, Labour and Welfare in 2015-2016. The following quality indicators were use: the adherence rate to the 2014 clinical practice guideline for polycystic kidney disease (prescription rates of antihypertensive agents and tolvaptan in this cohort) and the number of Japanese patients with ADPKD nationwide started on renal replacement therapy in 2014 and 2020. RESULTS: Compared with new applications from 2015 to 2016, the prescription rates of antihypertensives and tolvaptan for the indicated patients at the 2017 renewal application increased by 2.0% (odds ratio = 1.41, p = 0.008) and 47.4% (odds ratio = 10.1, p > 0.001), respectively. These quality indicators improved with antihypertensive treatment, especially in patients with chronic kidney disease stages 1-2 (odds ratio = 1.79, p = 0.013) and in those aged < 50 years (odds ratio = 1.70, p = 0.003). The number of patients with ADPKD who were started on renal replacement therapy in Japan decreased from 999 in 2014 to 884 in 2020 in the nationwide database (odds ratio = 0.83, p < 0.001). CONCLUSIONS: The Japanese public intractable disease support system contributes to improvement of ADPKD treatment.

[Retrospective Observational Study on Predictors of Body Weight and BNP Teduction in Cases of Tolvaptan Induction for Heart Failure].

Tolvaptan (TLV) carries the risk of serious side effects, and its introduction requires hospitalization. Therefore, it is important from the viewpoints of safety and medical economics to predict in advance, the patients for whom it will be effective and introduce it. The purpose of this study was to investigate the noninvasive and simple predictors for identifying TLV responders. We conducted a retrospective observational study of patients with heart failure who had TLV introduced at our hospital from January 1, 2017, to December 31, 2018. By using the body weight and BNP reduction as the effect indices, predictors of body weight and BNP reduction were extracted by logistic analysis. The sensitivity and specificity at the cutoff value obtained by ROC analysis were also examined. Among 85 subjects, urine sodium concentration >63 mEq/L [odds ratio (OR): 6.11, 95% confidence interval (CI): 1.36-27.4] was detected as a predictor of body weight reduction. The sensitivity at this cutoff value was 81%, and the specificity was 70%. Serum osmolarity>291 mOsm/L (OR: 3.76, 95% CI: 1.00-14.2), urine potassium concentration<21 mEq/L (OR: 4.45, 95% CI: 1.09-18.2), and urine sodium concentration>71 mEq/L (OR: 7.38, 95% CI: 2.05-26.6) were detected as predictors of BNP reduction. The sensitivities were 62%, 53%, and 73%, and the specificities were 58%, 68%, and 68%, respectively. Therefore, it was suggested that urine sodium concentration may be useful as a predictor of body weight and BNP decrease after TLV induction.

Clinical experience with Tolvaptan outpatient use. Cost and effectiveness in 9 cases.

INTRODUCTION: Tolvaptan introduction has constituted the main therapeutic novelty in the management of hyponatremia in recent years. OBJECTIVE: To describe the experience with this drug at Complejo Asistencial Universitario de León, Spain. METHOD: Retrospective, observational study of tolvaptan outpatient use in a tertiary care hospital from March 2014 to August 2017. RESULTS: A total of 9 patients were treated with tolvaptan in the outpatient setting. Eunatremia was reached in 24 h by 23.1%. After tolvaptan administration, a reduction in days of hospitalization was recorded (361 vs. 70; p = 0.007), especially in those days of hospitalization that were attributable to hyponatremia (306 vs. 49; p = 0.009). CONCLUSIONS: Long-term use of tolvaptan appears to be safe and is associated with a decrease in days of hospitalization.

INTRODUCCIÓN: La introducción de tolvaptan ha supuesto la principal novedad en el tratamiento de la hiponatremia en los últimos años. OBJETIVO: Describir la experiencia con tolvaptan en el Complejo Asistencial Universitario de León, España. MÉTODO: Estudio observacional retrospectivo de utilización ambulatoria de tolvaptan en un hospital de tercer nivel, de marzo de 2014 a agosto de 2017. RESULTADOS: Fueron tratados con tolvaptan de forma ambulatoria nueve pacientes, 23.1 % alcanzó eunatremia en 24 horas. Posterior a la administración de tolvaptan se registró reducción en días de hospitalización (361 versus 70, p = 0.007), especialmente por hiponatremia (306 versus 49, p = 0.009). CONCLUSIONES: El uso a largo plazo de tolvaptan parece ser seguro y se relaciona con descenso en los días de hospitalización.

Experiencia clínica con el uso ambulatorio de tolvaptan. Costes y efectividad en nueve casos / Clinical experience with Tolvaptan outpatient use. Cost and effectiveness in 9 cases

Resumen Introducción: La introducción de tolvaptan ha supuesto la principal novedad en el tratamiento de la hiponatremia en los últimos años. Objetivo: Describir la experiencia con tolvaptan en el Complejo Asistencial Universitario de León, España. Método: Estudio observacional retrospectivo de utilización ambulatoria de tolvaptan en un hospital de tercer nivel, de marzo de 2014 a agosto de 2017. Resultados: Fueron tratados con tolvaptan de forma ambulatoria nueve pacientes, 23.1 % alcanzó eunatremia en 24 horas. Posterior a la administración de tolvaptan se registró reducción en días de hospitalización (361 versus 70, p = 0.007), especialmente por hiponatremia (306 versus 49, p = 0.009). Conclusiones: El uso a largo plazo de tolvaptan parece ser seguro y se relaciona con descenso en los días de hospitalización.

Abstract Introduction: Tolvaptan introduction has constituted the main therapeutic novelty in the management of hyponatremia in recent years. Objective: To describe the experience with this drug at Complejo Asistencial Universitario de León, Spain. Method: Retrospective, observational study of tolvaptan outpatient use in a tertiary care hospital from March 2014 to August 2017. Results: A total of 9 patients were treated with tolvaptan in the outpatient setting. Eunatremia was reached in 24 h by 23.1%. After tolvaptan administration, a reduction in days of hospitalization was recorded (361 vs. 70; p = 0.007), especially in those days of hospitalization that were attributable to hyponatremia (306 vs. 49; p = 0.009). Conclusions: Long-term use of tolvaptan appears to be safe and is associated with a decrease in days of hospitalization.

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.

Autosomal Dominant Polycystic Kidney Disease: Clinical Assessment of Rapid Progression.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) causes the development of renal cysts and leads to a decline in renal function. Limited guidance exists in clinical practice on the use of tolvaptan. A decision algorithm from the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Working Groups of Inherited Kidney Disorders and European Renal Best Practice (WGIKD/ERBP) has been proposed to identify candidates for tolvaptan treatment; however, this algorithm has not been assessed in clinical practice. METHODS: Eighteen-month cross-sectional, unicenter, observational study assessing 305 consecutive ADPKD patients. The ERA-EDTA WGIKD/ERBP algorithm with a stepwise approach was used to assess rapid progression (RP). Subsequently, expanded criteria based on the REPRISE trial were applied to evaluate the -impact of extended age (≤55 years) and estimated glomerular filtration rate (eGFR; ≥25 mL/min/1.73 m2). RESULTS: Historical eGFR decline, indicative of RP, was fulfilled in 26% of 73 patients who were candidates for RP assessment, mostly aged 31-55 years. Further tests including ultrasound and MRI measurements of kidney volume plus genetic testing enabled the evaluation of the remaining patients. Overall, 15.7% of patients met the criteria for rapid or likely RP using the algorithm, and the percentage increased to 27% when extending age and eGFR. CONCLUSIONS: The ERA-EDTA WGIKD/ERBP algorithm provides a valuable means of identifying in routine clinical practice patients who may be eligible for treatment with tolvaptan. The impact of a new threshold for age and eGFR may increase the percentage of patients to be treated.

Economic impact of tolvaptan treatment vs. fluid restriction based on real-world data among hospitalized patients with heart failure and hyponatremia.

OBJECTIVES: To estimate the cost difference associated with tolvaptan treatment vs. fluid restriction (FR) among hospitalized patients with heart failure (HF) and hyponatremia (HN) based on a real-world registry of HN patients. METHODS: An Excel-based economic model was developed to evaluate the cost impact of tolvaptan treatment vs. FR. Model input for hospital length of stay (LOS) was based on published data from the Hyponatremia Registry (HNR). Based on HNR data, tolvaptan-treated patients had a 2-day (median) shorter LOS compared to FR. Real-world effectiveness of tolvaptan treatment from the HNR was applied to a national sample of inpatients visits from the Premier Hospital database to estimate the potential LOS-related cost difference between tolvaptan treatment and FR. A one-way sensitivity and multivariable Monte Carlo sensitivity analysis were conducted. RESULTS: Economic modeling results of the base-case analysis indicated that among hospitalized patients with HF, the hospital cost per admission, not including HN drug cost, was $3453 lower among patients treated with tolvaptan vs. FR, due to the shorter LOS associated with tolvaptan treatment. At wholesale acquisition cost of $362 per day and an average treatment duration of 3.2 days, the pharmacy cost of tolvaptan treatment per admission was estimated at $1157. Thus, after factoring the decrease in hospital medical costs and increase in pharmacy costs associated with tolvaptan treatment, results indicated a cost-offset opportunity of -$2296 per admission for patients treated with tolvaptan versus FR. Results of the sensitivity analyses were consistent with the base-case analysis. LIMITATIONS: The model derives inputs from real-world observational data. No causal relationship can be inferred from this analysis. CONCLUSIONS: Based on this economic analysis, tolvaptan treatment vs. FR among hospitalized patients with HF and HN may be associated with lower hospital-related costs, which offset the increase in pharmacy costs associated with tolvaptan treatment.

Utilization and budget impact of tolvaptan in the inpatient setting among patients with heart failure and hyponatremia.

OBJECTIVE: Assess characteristics of patients with heart failure (HF) and hyponatremia (HN) using tolvaptan, a selective vasopressin V2-receptor antagonist, for sodium correction, and estimate the budget impact of tolvaptan use in a hospital. METHODS: The Premier hospital database was analyzed to assess the utilization of tolvaptan, characteristics of users and non-users, and hospitalization costs among patients with HF and HN. Using these findings, a model was developed to estimate tolvaptan costs in proportion to total medical costs of managing patients with HF and HN, and the budget impact of tolvaptan use. Results were regenerated using data from the Healthcare Cost and Utilization Project (HCUP) database, and robustness was assessed in sensitivity analyses. RESULTS: Tolvaptan was used in 4.96% of inpatient visits among patients with HF and HN, more commonly among sicker patients as reflected in high utilization during intensive care stays (30.46%). Additionally, utilization increased by length of stay, which can serve as a proxy for disease severity. The model estimated that tolvaptan costs accounted for 0.3% of total hospitalization-related costs for patients with HF and HN, and the budget impact was $52.42 per visit. CONCLUSIONS: Results demonstrate that tolvaptan is used infrequently among patients with HF and HN, and is utilized among sicker patients. Tolvaptan accounted for 0.3% of total spending on management of inpatient visits with HF and HN, and had a marginal impact on hospital budget when compared with fluid restriction for HN correction. Availability of tolvaptan can provide an additional therapeutic option for sodium correction.

An economic analysis of tolvaptan compared with fluid restriction among hospitalized patients with hyponatremia.

OBJECTIVE: The vasopressin-receptor antagonist tolvaptan is used for the treatment of hyponatremia (HN) in hospitalized patients with congestive heart failure (CHF) or syndrome of inappropriate antidiuretic hormone secretion (SIADH). The objective of this economic modeling study was to assess the potential cost and health outcomes associated with tolvaptan in comparison with fluid restriction (FR). METHODS: A decision-analytic model was developed to estimate potential cost and health outcomes associated with tolvaptan compared with FR among hospitalized CHF and SIADH patients with severe HN (serum sodium [SS] levels < 125 mEq/L). The model, which was populated with data from the published literature, assumes that response to treatment influences hospital length of stay, probability of an intensive care unit (ICU) admission, and probability of a 30-day all-cause hospital readmission. One-way and probabilistic sensitivity analyses (PSAs) assessed the influence of parameter uncertainty on model results. RESULTS: Model results suggest that, among hospitalized CHF patients with severe HN, the use of tolvaptan compared with FR may lead to reductions of 7.2% and 4.6% in ICU admissions and 30-day readmissions, respectively. Compared with FR, tolvaptan may result in total cost-savings of $156 per hospitalized CHF patient. Among hospitalized SIADH patients with severe HN, the model suggested reductions of 14.6% and 5.1% in ICU admissions and 30-day readmissions, respectively. Compared with FR, tolvaptan may result in total cost-savings of $135 per hospitalized SIADH patient. PSAs found that the probabilities of net cost-savings from the use of tolvaptan compared with FR were 64% and 59% among patients with severe HN with CHF and SIADH, respectively. CONCLUSIONS: Decision-analytic modeling based on published data for hospitalized CHF and SIADH patients with severe HN, indicates that tolvaptan compared with FR has the potential to improve health outcomes and produce cost-savings that more than offset the cost of tolvaptan.

The V2 receptor antagonist tolvaptan raises cytosolic calcium and prevents AQP2 trafficking and function: an in vitro and in vivo assessment.

Tolvaptan, a selective vasopressin V2 receptor antagonist, is a new generation diuretic. Its clinical efficacy is in principle due to impaired vasopressin-regulated water reabsorption via aquaporin-2 (AQP2). Nevertheless, no direct in vitro evidence that tolvaptan prevents AQP2-mediated water transport, nor that this pathway is targeted in vivo in patients with syndrome of inappropriate antidiuresis (SIAD) has been provided. The effects of tolvaptan on the vasopressin-cAMP/PKA signalling cascade were investigated in MDCK cells expressing endogenous V2R and in mouse kidney. In MDCK, tolvaptan prevented dDAVP-induced increase in ser256-AQP2 and osmotic water permeability. A similar effect on ser256-AQP2 was found in V1aR -/- mice, thus confirming the V2R selectively. Of note, calcium calibration in MDCK showed that tolvaptan per se caused calcium mobilization from the endoplasmic reticulum resulting in a significant increase in basal intracellular calcium. This effect was only observed in cells expressing the V2R, indicating that it requires the tolvaptan-V2R interaction. Consistent with this finding, tolvaptan partially reduced the increase in ser256-AQP2 and the water permeability in response to forskolin, a direct activator of adenylyl cyclase (AC), suggesting that the increase in intracellular calcium is associated with an inhibition of the calcium-inhibitable AC type VI. Furthermore, tolvaptan treatment reduced AQP2 excretion in two SIAD patients and normalized plasma sodium concentration. These data represent the first detailed demonstration of the central role of AQP2 blockade in the aquaretic effect of tolvaptan and underscore a novel effect in raising intracellular calcium that can be of significant clinical relevance.

Tolvaptan Reduces Long-Term Total Medical Expenses and Length of Stay in Aquaporin-Defined Responders.

The vasopressin type-2 antagonist tolvaptan (TLV) has clinical advantages including amelioration of congestion and normalization of hyponatremia in patients with decompensated heart failure (HF). However, there have been no studies on the cost-effectiveness of TLV therapy. We enrolled 60 consecutive hospitalized patients with stage D HF who received TLV [TLV (+) group], and 60 propensity score-matched HF patients without TLV treatment [TLV (-) group]. We excluded 54 patients who died or received cardiac replacement therapy within 1 year, and finally enrolled 32 patients who received TLV and 34 who did not, who were followed for > 1 year. Among 45 aquaporin-defined responders, whose urine aquaporin-2 relative to plasma arginine vasopressin level was > 1.4 × 10(3) L/g Cre, the TLV (+) group required significantly lower total medical expenses and shorter lengths of stay (LOS) compared with the TLV (-) group [11.2 (1.233.3) versus 31.2 (2.2-71.4) × 10(5) JPY/year, P < 0.001; 30 (0-304) versus 70 (20-221) days, P = 0.030]. In contrast, among the remaining 21 aquaporin-defined non-responders, medical expenses and LOS were comparable irrespective of TLV administration (P = 0.087 and P = 0.407). In conclusion, TLV therapy may reduce total medical expenses in aquaporin-defined responders with stage D HF.

Cost-effectiveness of tolvaptan for the treatment of hyponatraemia secondary to syndrome of inappropriate antidiuretic hormone secretion in Sweden.

BACKGROUND: Tolvaptan is the only vasopressin V2 receptor antagonist licensed by the European Medicines Agency for the treatment of hyponatraemia (HN) secondary to the syndrome of inappropriate antidiuretic hormone secretion (SIADH). We have investigated the cost-effectiveness of tolvaptan versus no active treatment (NAT) in adult patients within the licensed indication who have either failed to respond to fluid restriction or for whom the use of fluid restriction is not suitable, from the societal perspective in Sweden. METHODS: A cost-utility analysis, considering a 'general SIADH' population and two subpopulations of patients (small-cell lung cancer [SCLC] and pneumonia) to broadly represent the complex clinical pathway of SIADH, was performed. A discrete event simulation was developed to model the progression of individuals through inpatient admissions over a 30-day time horizon (180 days for the SCLC cohort). Clinical data were derived from tolvaptan trials and observational data sources. All costs are given in Swedish kronor (SEK). RESULTS: In the 'general SIADH' population, tolvaptan was associated with reduced costs (SEK 5,779 per patient [€624]) and increased quality-adjusted life-years (QALYs) (0.0019) compared with NAT and was therefore the dominant treatment strategy. Tolvaptan was also associated with reduced costs and increased QALYs in the SCLC and pneumonia subpopulations. The most influential variables in our analysis were reduction in hospital length of stay, duration of treatment and long term treatment with tolvaptan in SCLC patients. CONCLUSIONS: Tolvaptan represents a cost-effective treatment option in Sweden for hospitalised patients with HN secondary to SIADH who have either failed to respond to or are unsuitable for fluid restriction.

Cost-effectiveness of tolvaptan for euvolemic or hypervolemic hyponatremia.

PURPOSE: Tolvaptan is clinically effective in increasing serum sodium concentrations for patients with euvolemic or hypervolemic hyponatremia. Appropriate treatment of hyponatremia may reduce the risk of death, hospital resource utilization, and economic burden. The aim of this study was to estimate the cost-effectiveness of tolvaptan treatment in patients who need to be hospitalized for treatment and monitoring of euvolemic or hypervolemic hyponatremia. METHODS: A decision-analytic model was constructed to assess the clinical and economic impact of tolvaptan compared with placebo during a 1-month treatment period. The probabilities, utility weights, resource utilization, and costs in the model were derived from clinical trials, survey research, and the Korean National Health Insurance database. Cost analysis was performed from the perspective of the South Korean health care setting in 2012 Korean won (KRW). The model outcome was the incremental cost per quality-adjusted life-year gained. In addition, subgroup analysis was performed to identify the cost-effectiveness in case of tolvaptan treatment only for patients with marked hyponatremia. Deterministic and probabilistic sensitivity analyses were performed on key model parameters and assumptions. FINDINGS: The total cost per patient was KRW 1,826,771 for tolvaptan treatment and KRW 2,281,926 for placebo. The quality-adjusted life-years for treatment with and without tolvaptan were 0.0481 and 0.0446, respectively. The base-case analysis revealed that tolvaptan was a more effective and less expensive strategy compared with placebo. In the subgroup analysis, this trend was more apparent in case of tolvaptan treatment only for patients with marked hyponatremia. The robustness of the results was confirmed by using deterministic and probabilistic sensitivity analyses. IMPLICATIONS: This cost-effectiveness analysis found that the use of tolvaptan was less expensive and more effective than treatment without tolvaptan in patients with euvolemic or hypervolemic hyponatremia.

Assessment of quality of life during long-term treatment of tolvaptan in refractory heart failure: design and rationale of the AQUA-TLV study.

The vasopressin type 2 receptor antagonist tolvaptan (TLV) has recently become available to treat congestion in in-hospital patients with heart failure (HF). However, there is no evidence confirming the long-term efficacy of TLV. The Assessment of Quality of life during long-term treatment of TLV in refractory heart failure (AQUA-TLV) study is a multicenter, open-labeled, randomized, controlled clinical trial that will enroll 100 patients from 18 hospitals in Japan. Patients with HF assigned to New York Heart Association class III or IV, who had a previous history of hospitalization due to congestive HF during the past 1 year and ongoing symptomatic congestion with baseline urine osmolality > 350 mOsm/L regardless of being prescribed daily furosemide ≥ 60 mg are randomized to the conventional diuretics group (50 patients) and TLV add-on group (50 patients), and their quality of life will be assessed using the Minnesota Living with Heart Failure Questionnaire after 6 months of treatment. This study is the first multicenter prospective randomized study in Japan to evaluate the long-term clinical effectiveness of TLV compared with conventional treatment in patients with congestive HF (UMIN Clinical Trial Registry Number: UMIN 000009604).

A potential novel strategy, inhibition of vasopressin-induced VEGF secretion by relcovaptan, for decreasing the incidence of ovarian hyperstimulation syndrome in the hyperstimulated rat model.

OBJECTIVE: To investigate the effects of V1A receptor antagonist through inhibition of vasopressin-induced VEGF secretion in an experimental model. STUDY DESIGN: Thirty rats were randomly divided into five groups. Four groups were given 10IU pregnant mare serum gonadotropin/day (sc) at 8:00-8:30am on days 22-25 of life. They were administered 30IU hCG at 8:00-8:30am on day 26 of life. On days 26 and 27 of life at 8:00am and 4:00pm, (ip) per animal, 50µg/kg/day GnRH antagonist in the GnRH antagonist group, 0.3mg relcovaptan in the high dose relcovaptan group, and 0.15mg relcovaptan in the low dose relcovaptan group were administered. The control group was given the same dosage of 0.9% saline solution (ip) on days 22-26 day of life. The main outcomes were weight gain, ovarian weights, peritoneal fluid VEGF values, corpus luteum count, and atretic follicle count. RESULTS: Weight gain was highest in the OHSS group; it was almost twice as much in the OHSS group than it was in the control group. Ovarian weights were significantly lower in all treatment groups (p=0.03). There was no statistically significant difference in ovarian weights between the GnRH antagonist and relcovaptan groups (p=0.176). The evaluation of peritoneal fluid VEGF-A levels revealed statistically significant differences between levels in the treatment groups and in the OHSS group (p=0.005). Atretic follicle count in the OHSS group was significantly lower (p=0.048). In all treatment groups, CL counts were prominently lower than they were in the OHSS group (p=0.002). CONCLUSION: Relcovaptan may be a novel strategy for decreasing risk of OHSS by inhibition of vasopressin-induced VEGF secretion through V1A receptor antagonist.

[Effectiveness and adequacy of tolvaptan prescription in hospitalized patients]. / Efectividad y adecuación de la prescripción de tolvaptán en pacientes hospitalizados.

PURPOSE: To analyse the effectiveness of the use of Tolvaptan and the adequacy of Tolvaptan prescription at a tertiary level hospital. METHODS: Prospective observational study of Tolvaptan prescrip - tion from October of 2010 to December of 2011. RESULTS: 30 patients (60.0% males) were included, 50.0% of which were diagnosed with heart failure and 30.0% with SIADH. Tolvaptan allowed achieving sodium levels higher than 135 mEq/L in 53.3% of the patients with a mean baseline value of 125.3±7.3 mEq/L. The median treatment duration was 5.0 days (interquartile range=3-45). A significant increase of uric acid associated to Tolvaptan treatment was observed. The prescription was in agreement to what has been established in GFT in 63.3% of the cases. CONCLUSIONS: Tolvaptan increases sodium levels by 7.5 mEq/L, both in SIADH-associated hyponatremia and in heart failure, with an appropriate safety profile.

Objetivo: Analizar la efectividad del uso de tolvaptán y la adecuación de su prescripción en un hospital de tercer nivel. Método: Estudio observacional prospectivo de las prescripciones de tolvaptán desde octubre de 2010 hasta diciembre de 2011. Resultados: Se incluyeron 30 pacientes (60,0% varones), 50,0% diagnosticados de insuficiencia cardíaca y 30,0% de SIADH. Tolvaptán permitió alcanzar niveles de sodio superiores a 135 mEq/L en el 53,3% de los pacientes que partían con una media de 125,3±7,3 mEq/L. La mediana de días de tratamiento fue de 5,0 (rango intercuartílico = 3-45). Se observó un incremento significativo de los niveles de ácido úrico asociado al tratamiento con tolvaptán. La prescripción se adecuó a lo establecido en la GFT en el 63,3% de los casos. Conclusiones: Tolvaptán incrementa un 7,5 mEq/L los niveles de sodio tanto en hiponatremia secundaria al SIADH como en insuficiencia cardiaca.

Where vaptans do and do not fit in the treatment of hyponatremia.

The treatment of hyponatremia, an exceedingly common electrolyte disorder, has been a subject of controversy for many years. The advent of vasopressin antagonists (vaptans) has added to the treatment arsenal. This review focuses on why hyponatremia should be treated and the role of these antagonists in the treatment. Upon analysis of the available literature, we conclude that there is presently no role for vaptans in acute symptomatic hyponatremia. Although numerous therapeutic approaches are available for chronic symptomatic hyponatremia, vasopressin antagonists provide a simpler treatment option. Vaptans are efficacious in raising serum sodium in long-standing 'asymptomatic' hyponatremia. However, the cost of the only Food and Drug Administration-approved oral agent (tolvaptan) makes its use prohibitive for most patients in this setting.

Update on tolvaptan for the treatment of hyponatremia.

Tolvaptan is a member of a new class of drugs, called the vaptans, that antagonize receptors of the neurohormone arginine vasopressin. From a clinical perspective, tolvaptan has been shown to be efficacious in the treatment of hyponatremia, whether it is idiopathic or disease related, and it may have a more favorable benefit/risk profile than other treatment modalities. From an economic perspective, tolvaptan is an expensive drug for treating hyponatremia, but recent economic cost-offset models provide evidence that tolvaptan can be cost effective. The cost-effectiveness of tolvaptan is driven by reduced healthcare resource usage and hospitalization costs. More comparative research of tolvaptan versus other pharmacotherapies and analyses of patients treated with tolvaptan in the real world are needed to better determine the benefits of tolvaptan usage to patient outcome, and more accurately assess its value in the treatment of hyponatremia, an independent predictor of morbidity, mortality and cost.