Background Hyponatraemia is the most frequent electrolyte disorder among elderly patients (9.4%–15.0% of prevalence). It is rarely attributed to pharmacological causes despite being one of the most common drug-induced electrolyte abnormalities. Although some studies have shown an increase in mortality, others have failed to confirm this association.

Purpose To estimate the prevalence of hyponatraemia in geriatric patients.

To determine which chronic drugs or alternative risk factors are associated with hyponatraemia and whether hyponatraemia is related to re-admission or mortality.

Material and methods We included ≥80 years’ old patients consecutively admitted from March to July 2018 in an Acute Geriatric Unit (81 beds) of a University Hospital. Data collected: age, sex, pre-admission Barthel and Pfeiffer tests, number and family of chronic drugs, laboratory test, comorbidities, length of stay (LOS), mortality, re-admission and mortality at 30 days post-discharge.

Conclusion The studied population displays hyponatraemia prevalence slightly above those of published values (see table 1). Hyponatraemia is associated with the use of thiazides and other factors such as age (>90 years), functional capacity, renal function and diabetes mellitus. Instead, re-admission and mortality rates remain unaltered.

References and/or acknowledgements No conflict of interest.