Drug-induced hyponatremia: an updated review

Hyponatremia, defined as serum sodium concentrations <135 mmol/L, is the most frequent electrolyte disturbance observed in both hospitalized and ambulatory patients, and has been associated to relevant negative consequences regarding morbidity and mortality. Drug-induced hyponatremia has been widely observed. However, since it may be clinically symptomatic or asymptomatic, it is frequently an underdiagnosed condition. This review aims to highlight the main drugs involved in the pathophysiology of hyponatremia, which should be considered in the differential diagnosis when approaching a patient with hyponatremia. We discuss their impact and relative importance. In order to prevent undesirable negative consequences we also emphasize the need for awareness of this clinically-relevant adverse effect, and we suggest how clinical management of patients may be approached.