Revista Científica de la Sociedad Española de Medicina de Urgencias y Emergencias

Servicio de Urgencias, Unidad de Corta Estancia y Unidad de Hospitalización a Domicilio, 2Servicio de Farmacia. Hospital General Universitario de Alicante. Spain.

Hyponatremia is a common electrolyte abnormality in emergency patients with acute heart
failure. The condition is multifactorial in origin but one of the principal mechanisms is
dysregulated vasopressin secretion. Treatment involves diuretics. Hyponatremia in acute
heart failure is conventionally managed by restricting oral intake of fluids, infusing a saline
solution, and administering diuretics. This approach may be effective, but it is complicated
and results can be unpredictable. Tolvaptan is a vasopressin antagonist that induces
diuresis of electrolyte-free water. Recent clinical trials have shown that tolvaptan is effective
in patients with hyponatremia due to various conditions, including heart failure. We report
10 cases of acute heart failure and hyponatremia treated with tolvaptan associated with
conventional management in the emergency department. Sodium levels returned to
normal rapidly without alteration of renal function or blood electrolytes. We describe our
experience with this drug and discuss issues related to diuretic treatment.