Short term efficacy and safety of low dose tolvaptan in patients with acute decompensated heart failure with hyponatremia: a prospective observational pilot study from a single center in South India

[Effectiveness of urea administration for the treatment of hyponatremia in heart failure]

OBJECTIVES

To assess the efficacy and safety of urea in patients with hyponatremia and heart failure (HF).

METHODS AND RESULTS

This is a retrospective observational analytical study of patients with HF and hyponatremia (Na+ <135mmol/L). Forty-nine patients treated with urea and 47 patients who did not receive urea, all under standard treatment (according to usual clinical practice) for HF, were included and followed up at Álvaro Cunqueiro Hospital in Vigo (Spain) between January 2013 and May 2022. The study evaluated the normalization of sodium levels (Na >135mmol/L). The initial natremia at the start of oral urea treatment was 127±5.22 mmol/L, at 24h the sodium level was 128±2.47 (P<.009), and the mean on the day of normalization was 135.19±4.23mmol/L (P<.005). The average number of days to achieve sodium normalization was 5.03±2.37 days. The initial uremia at the start of urea treatment was 73±46.93mg/dL, and the mean on the day of Na+ normalization was 116.05±63.64mg/dL (P<.002). The average oral urea dose was 22.5g/day. No relevant adverse effects were observed, nor were there significant changes in creatinine levels.

CONCLUSIONS

Oral urea treatment, when added to standard treatment for short periods of time, is safe and effective in correcting natremia in patients with hypervolemic HF with hyponatremia.

Oral delivery of metformin by chitosan nanoparticles for polycystic kidney disease

Nanoparticle drug delivery has many advantages over small molecule therapeutics, including reducing off-target side effects and increasing drug potency. However, many nanoparticles are administered parenterally, which is challenging for chronic diseases such as polycystic kidney disease (PKD), the most common hereditary disease worldwide in which patients need continuous treatment over decades. To address this clinical need, we present the development of nanoparticles synthesized from chitosan, a widely available polymer chosen for its ability to improve oral bioavailability. Specifically, we optimized the synthesis parameters of chitosan nanoparticles and demonstrate mucoadhesion and permeation across an intestinal barrier model in vitro. Furthermore, when administered orally to mice, ex vivo imaging of rhodamine-loaded chitosan nanoparticles showed significantly higher accumulation in the intestines compared to the free model drug, as well as 1.3 times higher serum area under the curve (AUC), demonstrating controlled release and improved serum delivery over 24 h. To test its utility for chronic diseases such as PKD, we loaded the candidate PKD drug, metformin, into chitosan nanoparticles, and upon oral administration to a PKD murine model (Pkd1fl/fl;Pax8-rtTA;Tet-O cre), a lower cyst burden was observed compared to free metformin, and was well tolerated upon repeated dosages. Blood urea nitrogen (BUN) and creatinine levels were similar to untreated mice, demonstrating kidney and biocompatibility health. Our study builds upon previous chitosan-based drug delivery approaches, and demonstrates a novel, oral nanoformulation for PKD.

Targeting and therapeutic peptide-based strategies for polycystic kidney disease

Polycystic kidney disease (PKD) is characterized by progressive cyst growth and is a leading cause of renal failure worldwide. Currently, there are limited therapeutic options available to PKD patients, and only one drug, tolvaptan, has been FDA-approved to slow cyst progression. Similar to other small molecule drugs, however, tolvaptan is costly, only moderately effective, and causes adverse events leading to high patient dropout rates. Peptides may mitigate many drawbacks of small molecule drugs, as they can be highly tissue-specific, biocompatible, and economically scaled-up. Peptides can function as targeting ligands that direct therapies to diseased renal tissue, or be potent as therapeutic agents themselves. This review discusses various aberrant signaling pathways in PKD and renal receptors that can be potential targets of peptide-mediated strategies. Additionally, peptides utilized in other kidney applications, but may prove useful in the context of PKD, are highlighted. Insights into novel peptide-based solutions that have potential to improve clinical management of PKD are provided.

Tolvaptan rescue contrast-induced acute kidney injury: A case report

RATIONALE

Contrast-induced acute kidney injury is one of the most serious adverse effects of contrast media and is related to three distinct but interacting mechanisms: medullary ischemia, formation of reactive oxygen species and direct tubular cell toxicity, especially in the patients with chronic kidney disease. The strategies of treatment, including stabilization of hemodynamic parameters and maintenance of normal fluid and electrolyte balance, were similar to the management of other types of acute kidney injury.

PATIENT CONCERNS

A 58-year-old woman experienced acute oligouria after complex percutaneous coronary intervention for multiple vessel coronary artery disease.

DIAGNOSES

Chest radiography showed pulmonary congestion and hyponatremia was noted after fluid hydration for suspicious contrast-induced nephropathy.

INTERVENTIONS

Oral tolvaptan, at 15mg per day, was used for three days.

OUTCOMES

Urine output increased gradually and symptoms relieved one day later after using tolvaptan. Serum creatinine also improved to baseline level one week later after this event.

LESSONS

Here, we reported an interesting case about contrast-induced acute kidney injury and hypervolemic hyponatremia, where tolvaptan was used to rescue the oliguric phase. Tolvaptan could be considered to use for contrast-induced acute kidney injury and had possibility of prevention from hemodialysis. Larger studies are still needed to investigate the role of tolvaptan in rescuing the oliguric phase in contrast-induced acute kidney injury.

Effect of tolvaptan on acute heart failure with hyponatremia--a randomized, double blind, controlled clinical trial

Objectives

To assess the efficacy of tolvaptan in acute heart failure with hyponatremia using a randomized double-blinded placebo-controlled study design.

Background

Tolvaptan is a selective vasopressin receptor 2 antagonist. There are no published clinical trials on the utility of tolvaptan in acute heart failure with hyponatremia in the Indian population.

Methods

After screening and informed consent, 51 HF patients with hyponatremia were randomized using computer-generated randomization sequence to receive placebo or 15 mg of tolvaptan for 5 days along with conventional medical therapy. The patient's perception of dyspnea using Likert score and the plasma sodium was measured at baseline and for the next 4 days.

Results

There was a mean improvement in sodium concentration by 5 mEq/L (p = 0.001) in patients receiving tolvaptan, whereas no significant improvement was seen in the placebo group (p = 0.33). Significant improvement in Likert score was observed in both the groups (p = 0.001), even though there was no difference between both the groups. Dry mouth and thirst were the most commonly occurring adverse effects observed in both the groups. There were no significant hemodynamic changes with tolvaptan therapy.

Conclusion

Tolvaptan at a dose of 15 mg is effective in reversing hyponatremia in acute heart failure and may be a suitable option in these patients.