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. 2025 Jul 31;11(1):63.
doi: 10.1186/s40780-025-00476-9.

Syndrome of inappropriate antidiuretic hormone secretion in a patient with colon cancer using CAPOX plus bevacizumab therapy: a case report

Masanobu Uchiyama  1 , Takafumi Inoue  2 , Daibo Kojima  3 , Masato Watanabe  3 , Motoyasu Miyazaki  4 , Takafumi Nakano  5 , Takuya Yamashina  5 , Osamu Imakyure  4 , Koichi Matsuo  5
Affiliations

Syndrome of inappropriate antidiuretic hormone secretion in a patient with colon cancer using CAPOX plus bevacizumab therapy: a case report

Masanobu Uchiyama et al. J Pharm Health Care Sci. .

Abstract

Background: Hyponatremia is an electrolyte abnormality that is often caused by the syndrome of inappropriate antidiuretic hormone secretion (SIADH) and frequently encountered in the field of oncology. Although SIADH is a known complication of certain chemotherapeutic agents, its occurrence with oxaliplatin is rare. We report a case of SIADH in a patient with colon cancer who was undergoing treatment comprising capecitabine and oxaliplatin (CAPOX) plus bevacizumab.

Case presentation: A 70-year-old man with stage cT4bN2M0 colon cancer underwent chemotherapy with CAPOX plus bevacizumab. On day 7 of treatment, the patient developed severe hyponatremia (serum sodium level, 108 mmol/L) accompanied by nausea and ileus. Laboratory test results were consistent with SIADH, including low serum osmolality, elevated urine osmolality, elevated sodium concentration, and elevated antidiuretic hormone levels. The condition improved with 3% saline infusion and fluid restriction. No other underlying causes, such as central nervous system lesions or adrenal or thyroid dysfunction, were identified. CAPOX-induced SIADH was diagnosed based on clinical findings and the exclusion of other etiologies. Transition to second-line therapy was performed without SIADH recurrence.

Conclusions: Oxaliplatin-based regimens may rarely induce SIADH. Clinicians should be vigilant of electrolyte disturbances during chemotherapy and promptly manage hyponatremia to avoid severe complications.

Keywords: Bevacizumab; Capecitabine; Colon cancer; Hyponatremia; Oxaliplatin; Syndrome of inappropriate antidiuretic hormone secretion.

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Conflict of interest statement

Declarations. Ethics approval and consent to participate: Ethical approval was waived for this case report as it does not meet the criteria for human subject research requiring Institutional Review Board of Fukuoka University Chikushi Hospital review. Consent for publication: Consent for the publication of this case report was obtained from the patient’s wife as a representative because the patient was no longer alive at the time of submission to this journal. Competing interests: The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Clinical course of the patient after capecitabine and oxaliplatin (CAPOX) plus bevacizumab therapy
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References

    1. Palmer BF, Gates JR, Lader M. Causes and management of hyponatremia. Ann Pharmacother. 2003; 37: 1694–702. Available from: 10.1345/aph.1D105 - PubMed
    1. Onitilo AA, Kio E, Doi SA. Tumor-related hyponatremia. Clin Med Res. 2007; 5: 228–37. Available from: 10.3121/cmr.2007.762 - PMC - PubMed
    1. Raftopoulos H. Diagnosis and management of hyponatremia in cancer patients. Support Care Cancer. 2007; 15: 1341–7. Available from: 10.1007/s00520-007-0309-9 - PubMed
    1. Berghmans T. Hyponatremia related to medical anticancer treatment. Support Care Cancer. 1996; 4: 341–350. Available from: 10.1007/BF01788840 - PubMed
    1. Iyer AV, Krasnow SH, Dufour DR, Arcenas AS. Sodium-wasting nephropathy caused by cisplatin in a patient with small-cell lung cancer. Clin. Lung Cancer. 2003, 5, 187–9. Available from: 10.3816/CLC.2003.n.033 - PubMed

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