Abstract: TH-PO340
Low-Dosage Tolvaptan for Refractory Hyponatremia in Fontan-Associated Cardiac Cirrhosis
Session Information
- Sodium, Potassium, and Volume Disorders: Clinical
October 24, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Fluid, Electrolytes, and Acid-Base Disorders
- 1102 Fluid, Electrolyte, and Acid-Base Disorders: Clinical
Authors
- Bhenswala, Prashant N., Northwell Health, New Hyde Park, New York, United States
- Upadrista, Pratap Kumar, Northwell Health, New Hyde Park, New York, United States
- Sharma, Purva D., Northwell Health, New Hyde Park, New York, United States
Introduction
Hyponatremia in cardiac cirrhosis is challenging to manage. Fontan surgery is a palliative procedure for patients with single ventricle congenital heart lesions that diverts blood from the great veins to the pulmonary arteries, bypassing the right ventricle. Patients develop elevated CVP and cardiac cirrhosis with hyponatremia that is typically managed with a combination of loop diuretics and mineralocorticoid receptor antagonists. Our patient had refractory fluid overload and hyponatremia necessitating Tolvaptan use with good results and no adverse events.
Case Description
A 45-year-old male with hx of Fontan procedure complicated by Fontan Associated Liver Disease requiring paracenteses every 3 weeks, came to the ED for a serum Na of 122 mEq/L. He was on 1 L water restriction and maximally tolerated diuretics of Furosemide 40 mg and Spironolactone 25 mg daily but remained hyponatremic needing more frequent paracenteses and hospitalizations. Physical exam revealed a BP of 85/48 mm Hg, thin appearing male, with ascites and anasarca. Serum osmolality was 266 mosmol/kg. Urine studies: sodium 7 mmol/L, potassium 45 mmol/L, osmolality of 628 mosm/kg indicative of ADH mediated hyponatremia. Despite his history of cirrhosis, low dose Tolvaptan (7.5 mg) was given. Serum Na level appropriately increased from 125 mEq/L to 135 mEq/L over 4 days. The patient was discharged on Tolvaptan 7.5 mg once a week in addition to his home diuretics and has remained stable with a serum Na of 130-133 mEq/L with a reduced need for hospitalizations and paracenteses. Serum creatinine has remained stable at 1.2 mg/dL.
Discussion
Tolvaptan is an arginine vasopressor V2 receptor antagonist promoting excretion of free water. While not contraindicated, it is recommended to avoid use of Tolvaptan in patients with cirrhosis due to the risk of liver failure and variceal bleed. However, owing to the refractory nature of this patient’s hyponatremia and limited alternative therapies, low dose weekly Tolvaptan was initiated. Treatment led to controlled and sustained correction of serum Na level and reduction in hospitalizations for fluid overload. Tolvaptan should be considered as alternative therapy for refractory hyponatremia in cirrhosis. Altered pharmacokinetics of the drug in cirrhosis may enable use of a lower dose and frequency for the same effect with no appreciable adverse events.