A case of chronic hypomagnesemia in a cancer survivor

Hosp Pract (1995). 2017 Apr;45(2):58-64. doi: 10.1080/21548331.2017.1286924. Epub 2017 Feb 6.


Objectives: Hypomagnesemia is common among hospitalized patients, particularly those who are critically ill. It can be associated with a number of potentially life-threatening cardiovascular, neurological and behavioral manifestations. As opposed to acute, chronic hypomagnesemia is often underdiagnosed and underreported and as such may pose a diagnostic and therapeutic problem.

Case presentation: We describe a case of magnesium wasting in a middle-aged woman with head and neck cancer who presented with recurrent syncopal episodes complicated by a femur fracture 4 months after completing a course of carboplatin-containing chemotherapy. Fractional excretion of magnesium of 16% was consistent with renal wasting of magnesium. After ruling out all common causes of hypomagnesemia, it was concluded that she sustained carboplatin-induced renal tubular damage making her relatively resistant to magnesium supplementation.

Conclusion: Several antineoplastic agents have been linked to chronic hypomagnesemia including anti-epidermal growth factor receptor agents such as cetuximab and panitumumab, cyclosporine, and the platinum-based agents cisplatin and carboplatin. The example case presented here illustrates the importance of chronic hypomagnesemia and its possible debilitating effects following carboplatin-containing chemotherapy. A growing numbers of cancer survivors are treated with these antineoplastic agents, and are hospitalized for non-cancer-related problems. These patients may have prolonged hypomagnesemia, and hence pose a diagnostic dilemma. We review the pathophysiology, etiology, diagnosis, clinical manifestations, monitoring and treatment of hypomagnesemia, with special attention to mechanisms of renal damage caused by platinum-containing chemotherapeutic agents.

Keywords: Chronic hypomagnesemia; carboplatin; chemotherapy; head and neck cancer; magnesium wasting.

MeSH terms

  • Carboplatin / adverse effects*
  • Carboplatin / therapeutic use
  • Chronic Disease
  • Female
  • Femoral Fractures / pathology
  • Head and Neck Neoplasms / drug therapy
  • Humans
  • Kidney Diseases / chemically induced*
  • Kidney Diseases / complications*
  • Magnesium / blood*
  • Middle Aged
  • Survivors
  • Syncope / pathology


  • Carboplatin
  • Magnesium