Salt Tablets Safely Increase Serum Sodium in Hospitalised Elderly Patients With Hyponatraemia Secondary to Refractory Idiopathic Syndrome of Inappropriate Anti-Diuresis

Hyponatraemia is the most common electrolyte abnormality encountered in the inpatient setting and is associated with increased morbidity, mortality, and length of hospital stay. Syndrome of inappropriate anti-diuresis (SIAD) remains the most common cause. Hyponatraemia due to SIAD presents various challenges in treatment approaches, including poor concordance (e.g., to fluid restriction), medication intolerance (e.g., demeclocycline), and risk of rapid sodium shifts (e.g., with vaptan therapy). The use of oral sodium chloride (NaCl) tablets is a recognised treatment approach. However, it is not commonly advocated. We present the cases of two elderly patients in whom the temporary use of NaCl tablets, as an adjunct to fluid restriction, led to safe and effective correction of SIAD-related hyponatraemia with resultant reduced length of hospital admission.