RESUMEN
Hyponatremia is one of the most common electrolyte abnormality seen in oncology practice. The underlying pathogenetic mechanism for chemotherapy-induced hyponatremia is renal salt-wasting syndrome (RSWS) and syndrome of inappropriate antidiuretic hormone secretion (SIADH). Fluid restriction is the treatment of choice in SIADH, whereas salt supplements is the mode of treatment in RSWS. Hence, differentiation between RSWS and SIADH is very important though difficult. Case reports of cisplatin (cis-dichloro-diammine-platinum-2)-induced RSWS and SIADH are rare in the literature. We report about a patient who developed hyponatremia, hypokalemia with excessive urinary excretion of sodium and potassium, renal glycosuria, and aminoaciduria on the third day of the first cycle of cisplatin-containing chemotherapy.