title: A rapid and efficient way to manage hyponatremia in patients with SIADH and small cell lung cancer: treatment with tolvaptan.
abstract: BACKGROUND
  Hyponatremia based on syndrome of inappropriate antidiuretic hormone hypersecretion (SIADH) is observed in up to 15% of patients with small cell lung cancer (SCLC). The electrolyte imbalance is associated with a high morbidity and mortality and often delays appropriate treatment. Management of hyponatremia proved to be challenging until new vasopressin-2 receptor antagonists such as tolvaptan became available. This is the first report which presents a prospective case series with an efficient management of hyponatremia including tolvaptan in ten patients with SCLC and severe SIADH (plasma sodium < 125 mmol/l).
  
  
  METHODS
  Ten patients with SCLC and severe SIADH were followed after the onset of clinical symptoms of SIADH. Patients were chosen on the basis of histological proven diagnosis of SCLC and the clinical picture of a neurocognitive deficit caused by SIADH-related hyponatremia. All patient data were monitored for clinical improvement based on ECOG status, commencement of chemotherapy and correction of sodium levels.
  
  
  RESULTS
  The treatment followed a diagnostic and treatment algorithm and lead to a rapid and efficient correction of both clinical symptoms and plasma sodium level.
  
  
  CONCLUSIONS
  Based on this algorithm all patients started chemotherapy in time. Subsequently, the treatment with tolvaptan lead to an improvement of the ECOG-performance status. In addition, all patients benefit from the effective management of SIADH which omitted prolonged hospital stays and non-elective hospitalizations due to an unstable clinical condition due to severe hyponatremia. These observations add new insight to management of SIADH in thoracic oncology and are of interest for specialists in oncology, endocrinology and pulmonary medicine.
authors.affiliation: ELK Department of Respiratory Diseases, Lindenberger Weg 27, 13125, Berlin, Germany. christian.grohe@elk-berlin.de.
authors.forename: Claudia
authors.initials: C
authors.lastname: Petereit
authors.forename: Okan
authors.initials: O
authors.lastname: Zaba
authors.forename: Ishak
authors.initials: I
authors.lastname: Teber
authors.forename: Heike
authors.initials: H
authors.lastname: Lüders
authors.forename: Christian
authors.initials: C
authors.lastname: Grohé
mesh_terms: D000368:Aged; D000465:Algorithms; D065092:Antidiuretic Hormone Receptor Antagonists; D001552:Benzazepines / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D007177:Inappropriate ADH Syndrome / Q000209:etiology*; D008175:Lung Neoplasms / Q000150:complications*; D008297:Male; D008875:Middle Aged; D055752:Small Cell Lung Carcinoma / Q000150:complications*; D012964:Sodium / Q000097:blood; D000077602:Tolvaptan
chemical_list: D065092:Antidiuretic Hormone Receptor Antagonists; D001552:Benzazepines; D000077602:Tolvaptan; D012964:Sodium