Tolvaptan Reduces Extracellular Fluid per Amount of Body Fluid Reduction Less Markedly than Conventional Diuretics
Hirotsugu Iwatani1, Masafumi Yamato1, Saki Bessho1
1Department of Nephrology, National Hospital Organization Osaka National Hospital, Japan.
Internal Medicine (Tokyo, Japan)
|February 3, 2022
Summary
Tolvaptan, a vasopressin V2 receptor antagonist, reduces extracellular fluid less than conventional diuretics for the same amount of body fluid removed. This finding is crucial for managing fluid retention in chronic kidney disease (CKD) patients.
Area of Science:
- Nephrology
- Pharmacology
- Physiology
Background:
- Tolvaptan is a vasopressin V2 receptor antagonist acting as a water diuretic.
- It reduces intracellular fluid volume and is associated with a low incidence of worsening renal function.
- Conventional diuretics can worsen renal function in patients with fluid retention.
Purpose of the Study:
- To compare the effect of tolvaptan combined with conventional diuretics versus conventional diuretics alone on body fluid composition in chronic kidney disease (CKD) patients.
- To evaluate the impact of tolvaptan on extracellular water (ECW) and total body water (TBW) ratio.
Main Methods:
- A retrospective observational study involving five CKD patients treated with tolvaptan and conventional diuretics.
- Bioelectrical impedance (BIA) analysis was used to assess body fluid composition before and after therapy.
- Comparison of the ECW/TBW ratio changes between the tolvaptan group and 18 patients receiving conventional diuretics alone.
Main Results:
- Both tolvaptan and conventional diuretics reduced the ECW/TBW ratio.
- The reduction in extracellular fluid was less pronounced in the tolvaptan group compared to the conventional diuretics group, relative to the amount of body fluid removed.
Conclusions:
- Tolvaptan, when used with conventional diuretics, results in a milder reduction of extracellular fluid per unit of body fluid removed compared to conventional diuretics alone.
- This suggests a potentially more favorable fluid management strategy for CKD patients with fluid retention.
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