RESUMO
Introduction: As bipolar disorder often requires long-term lithium treatment, assessment of adverse effects is critical. Long-term treatment with lithium induces functional and / or structural disturbances in the kidneys. Nephrogenic diabetes insipidus (NDI) occurs in up to 40% of lithium users and leads to a 2-3 times increased risk of chronic kidney disease. Polyuria-associated fluid imbalances and NDI, increase the risk of hypernatremia. Without appropriate and quick treatments, hypernatremia can easily lead to life-threatening consequences. A major adverse effect, hypernatremia secondary to kidney injury induced by lithium should not be misdiagnosed. We report cases of three patients with mood disorders treated with long-term lithium therapy. They presented to our hospital during the state of emergency declared by the Japanese government in response to curb the coronavirus disease (COVID-19) pandemic. They showed hypernatremia and disturbance of consciousness. All three patients had been taking lithium for more 10 years and had dehydration and / or renal damage on admission. The main cause of clinically significant hypernatremia is not drug-induced kidney injury after long-term lithium treatment, but lithium is one of the most common causes of acquired NDI. Case Report: Case 1 A 65-year-old man with a history of bipolar disorder and presented with polyurea, dehydration, and altered consciousness. He had been on lithium carbonate (800 mg twice daily) for over 20 years. Case 2 A 58-year-old woman with recurrent depressive disorder presented with high fever, drowsiness, spasms, and a highly serum creatine phosphokinase. She was admitted to the emergency department to rule out neuroleptic malignant syndrome. She was prescribed lithium carbonate (800 mg twice daily), but was not fully compliant with the treatment. Case 3 A 72-year-old-woman with bipolar disorder and history of hospitalizations at a mental-health rehabilitation institution presented with disturbance of consciousness and psychomotor retardation. She had been on lithium carbonate (400 mg twice daily) for 16 years. Oral dyskinesia and dysarthria were observed as were high fever and confusion. Of the three patients, one was a COVID-19 patient, while the others were not: however, all of them showed hypernatremia. A cohort study showed that infection, intoxication other than lithium, and dehydration were the main causes of hypernatremia. Lithium intoxications only accounted for 1% of all hypernatremia episodes. Probably the COVID-19 infection may directly cause hypernatremia, and dehydration may indirectly cause hypernatremia owing to a close ward, delirium, and physical restraint because they cannot complain about thirst. The COVID-19 pandemic affects the mental health of patients with bipolar disorder. Amounts of alcohol, soft drinks, and food can potentially trigger symptoms of kidney injury and diabetes. Conclusion: These patients with mood disorders after long-term lithium therapy must be carefully monitored their mental condition, including delirium, their complaints, and laboratory data to avoid overlooking severe conditions. [1,2]