[Symptomatic therapy of SIADH in small cell lung cancer by tolvaptan].

HISTORY AND CLINICAL FINDINGS: A 69-year-old woman with small cell lung cancer presented in the emergency ward because of severe back pain. She had received tolvaptan treatment in hospital for paraneoplastic SIADH but had discontinued the drug after discharge from hospital 3 days ago. Restriction of fluid intake was not tolerated.

INVESTIGATIONS: Consistent with SIADH, there were profound hyponatraemia, elevated urine osmolality and urine sodium.

TREATMENT AND COURSE: After a generalized seizure triggered by hyponatraemia, tolvaptan was reintroduced in addition to radiochemotherapy. Serum sodium concentration increased and finally returned to normal.

CONCLUSION

If restriction of fluid intake is not tolerated by the patients the vasopressin antagonist tolvaptan provides an alternative symptomatic treatment of paraneoplastic SIADH.