Antiseizure medication-induced hyponatraemia

Hyponatraemia is a well-documented side effect of antiseizure medication (ASM). Its management involves balancing the risks of untreated hyponatraemia against the risks of upsetting seizure control by altering the ASM. The first consideration is to exclude other causes of hyponatraemia. The management should be informed by the degree of hyponatraemia, the severity of symptoms and the patient's preference. Management options include conservative treatment; active sodium correction, such as through fluid restriction and stopping medications other than ASM that could be associated with hyponatraemia, where possible; ASM regimen changes might include reducing the dose or switching ASM. ASMs vary in their tendency to induce hyponatraemia-oxcarbazepine and carbamazepine have the highest risk-which is important to consider when switching to an alternative ASM.