Sacubitril/valsartan-induced hyponatremia in a cancer survivor

Hyponatremia in patients with cancer is common and often multifactorial, complicating the management of heart failure and anticancer therapies. Sacubitril/valsartan, a combined neprilysin inhibitor and angiotensin receptor blocker, is a cornerstone therapy for heart failure with reduced ejection fraction, but it may have adverse effects that are clinically significant. We present a case of a 54-year-old woman with poor-risk acute myeloid leukemia in remission after allogeneic hematopoietic stem cell transplantation who developed recurrent hyponatremia temporally associated with sacubitril/valsartan use. Cessation of the medication led to sodium improvement. This case highlights the need for increased clinical suspicion for drug-induced hyponatremia in onconephrology patients treated with neprilysin inhibitors.