European Journal of Clinical Pharmacology

, Volume 74, Issue 2, pp 245–246 | Cite as

Secondary resistance to tolvaptan in two patients with SIAD due to small cell lung cancer

  • A. GarrahyEmail author
  • A. M. Hannon
  • H. M. Zia-Ul-Hussnain
  • D. J. Williams
  • C. J. Thompson
Letter to the Editor


Syndrome of inappropriate antidiuresis (SIAD) is characterized by euvolaemic hyponatraemia due to the antidiuretic effects of inappropriate elevation of plasma vasopressin (pAVP, also referred to as antidiuretic hormone (ADH)). Randomized controlled trials report a good response to tolvaptan-induced vasopressin receptor blockade, with reversal of hyponatremia in SIAD [1], including those with lung cancer [2]. Prolonged treatment is effective for up to four years [3]. We report two patients with small cell lung cancer (SCLC) who showed an initial good response to tolvaptan, but who subsequently displayed resistance to the aquaretic effects of the drug.

Case 1

A 58-year-old male smoker presented with headache and unsteadiness. Plasma sodium (pNa) was 107 mmol/L; he was euvolaemic and SIAD was diagnosed (see supplementary data). CT showed a lung mass, and bronchoscopy confirmed SCLC. PNa rose with fluid restriction to 124 mmol/L, with improvement in symptoms. He was unable to...



We thank Dr. Chris Boot (Newcastle upon Tyne) for the measurement of plasma copeptin.

Compliance with ethical standards

Conflict of interest

Professor Chris Thompson has received honoraria for lectures from Otsuka.

Dr. Aoife Garrahy, Dr. Anne Marie Hannon, Dr. Zia-Ul-Hussnain, and Professor David Williams have no potential conflicts of interest.

Supplementary material

228_2017_2363_MOESM1_ESM.docx (47 kb)
ESM 1 (DOCX 46 kb)


  1. 1.
    Schrier RW, Gross P, Gheorghiade M, Berl T, Verbalis JG, Czerwiec FS et al (2006) Tolvaptan, a selective oral vasopressin V2-receptor antagonist, for hyponatremia. N Engl J Med 355(20):2099–2112CrossRefPubMedGoogle Scholar
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    Salahudeen AK, Ali N, George M, Lahoti A, Palla S (2014) Tolvaptan in hospitalized cancer patients with hyponatremia: a double-blind, randomized, placebo-controlled clinical trial on efficacy and safety. Cancer 120(5):744–751CrossRefPubMedGoogle Scholar
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    Berl T, Quittnat-Pelletier F, Verbalis JG, Schrier RW, Bichet DG, Ouyang J et al (2010) Oral tolvaptan is safe and effective in chronic hyponatremia. J Am Soc Nephrol 21(4):705–712CrossRefPubMedPubMedCentralGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2017

Authors and Affiliations

  • A. Garrahy
    • 1
    Email author
  • A. M. Hannon
    • 1
  • H. M. Zia-Ul-Hussnain
    • 1
  • D. J. Williams
    • 2
  • C. J. Thompson
    • 1
  1. 1.Academic Department of EndocrinologyBeaumont Hospital and RCSI Medical SchoolDublinIreland
  2. 2.Department of Geriatric and Stroke MedicineBeaumont Hospital and RCSI Medical SchoolDublinIreland

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