Precipitation of hyponatremia and seizures by esmolol in sterile water formulation.

Purpose: Acute hyponatremia can lead to severe neurological symptoms such as confusion, obtundation, seizures, coma, and respiratory depression, contributing to increased morbidity and mortality. Patients with acute hyponatremia should be evaluated based on volume status and serum osmolality to determine potential causes and appropriate treatment. The aim of this case report is to illustrate the importance of using a multidisciplinary approach to evaluate medication formulation and the potential impact on a patient's clinical course.

Summary: A 34-year-old male was admitted for type A aortic dissection and was treated with an esmolol infusion and underwent operative repair. Two days after initiation of esmolol, the patient developed seizures and antiepileptics were initiated. The patient's serum sodium concentration was found to have decreased by a total of 14 mEq/L since admission. The patient had received more than 6 L of esmolol formulated in sterile water over the course of 2 days. The esmolol infusion was converted to another antihypertensive agent, and 0.9% sodium chloride injection was initiated, after which the serum sodium concentration began to recover. No further seizures were observed on continuous electroencephalography, and all antiepileptic drugs were discontinued with no seizure activity.

Conclusion: The esmolol product utilized in this case was formulated in 250 mL of sterile water, which is suspected to have contributed to the patient's hyponatremia. It is important to be aware of the formulation and excipients of medications and their potential for adverse effects.