Antidepressant induced recurrent hyponatremia: A case report

Abstract

Hyponatremia is a known adverse effect of antidepressants. A review of the literature was performed in relation to one case treated in our hospital to identify risk factors and possible psychopharmacologic alternatives. A 57-year old woman with HIV and HCV suffered 4 episodes of severe hyponatremia within 5 months of treatment involving the following drugs: thiazide diuretic, venlafaxine, citalopram, olanzapine, haloperidol, enalapril and escitalopram. Risk of hyponatremia is higher in patients treated with antidepressants, especially selective serotonin reuptake inhibitors. Advance age, female gender, thiazidic diuretics, sodium levels in the lower limits and low weight increase the risk. All the SSRIs can produce hyponatremia. In most of the cases, this effect appears in the first month. It is not dose dependent and the patient recovers when treatment is interrupted. Early detection as well as the evaluation of concomitant risk factors in all patients starting antidepressant are important. It seems necessary to control ions periodically and to choose safe drugs.