Drug Induced Hyponatremia in the Elderly

Hyponatremia is the most common electrolyte imbalance and usually induced by renal water retention due to the presence of factors contributing to increased antidiuretic hormone, low glomerular filtration rate and poor intake of salt and protein in the elderly population.Although symptom severity varies according to the severity, duration and rapidity of hyponatremia, mild chronic hyponatremia is associated with frailty, osteoporosis, cognitive impairment and gait disturbance.The syndrome of inappropriate antidiuretic hormone secretion and endocrinopathies such as hypothyroidism and adrenal insufficiency are major causes of hyponatremia, but medications have been considered as an important factor of water imbalance, and thiazide diuretics, psychotropic agents, anticancer chemotherapeutic drugs and vasopressin analogues are major hyponatremia-inducing drugs in clinical practice.Syndrome of inappropriate anti-diuresis (SIAD) is a main pathogenesis of drug-induced hyponatremia, but multifactorial factors are associated with hyponatremia in old patients.Clinicians should prescribe these potential drugs with caution, especially in those with risk factors for SIAD.The treatment of hyponatremia depends on the severity and type of hyponatremia, and all offending drugs should be discontinued and re-administration of these drugs is strongly discouraged.(PeRM