摘要
Hyponatremia related to ectopic secretion of cancer cells of arginine vasopressin(AVP)or atrial natriuretic peptide(ANP)is most commonly caused by small cell lung cancer.The ideal treatment would be one that not only corrects the hyponatremia,especially if it is life threatening,but at the same time causes regression of the cancer,and thus improves both quality and length of life.As one is waiting for chemotherapy,surgery,or radiotherapy to decrease the cancer burden,tolvaptan has been used to correct the hyponatremia to improve symptoms or prevent death.Mifepristone,a progesterone receptor modulator/antagonist has been used to treat various cancers.The oral 200mg tablet was given to an 80-year-old woman who developed sudden extensive lung cancer with a serum sodium of 118 mmol/L.She refused chemotherapy but agreed to take mifepristone.The hyponatremia was completely corrected(145 mmol/L)within one month of treatment.She was in complete remission for 5 years and died not from lung cancer,but an acute myocardial infarction.Mifepristone may serve the purpose to not only quickly correct hyponatremia when it is related to an endocrine paraneoplastic syndrome,but also to provide improved quality and length of life.
