title: Cetuximab-induced hypomagnesemia in patients with colorectal cancer.
abstract: BACKGROUND
  Cetuximab treatment has been associated with severe hypomagnesemia, but the predisposing factors and management of this toxicity have been poorly characterized.
  
  
  METHODS
  The charts of 114 patients with colorectal cancer treated with cetuximab were reviewed. Forty-eight evaluable patients had normal magnesium levels before initiation of cetuximab and >or=1 repeat magnesium level during cetuximab treatment. The incidence, grade, and management of hypomagnesemia were described in the evaluable population.
  
  
  RESULTS
  Among the evaluable population, 13 patients developed grade 3/4 hypomagnesemia (27%). The incidence of grade 3/4 hypomagnesemia was 6%, 23%, and 47% in patients receiving < 3 months, 3-6 months, and > 6 months of cetuximab therapy, respectively. Grade 3/4 hypomagnesemia was refractory to oral supplementation and required daily to 3-times-weekly intravenous magnesium sulfate supplementation at 6-10 g per dose. Recovery or amelioration in hypomagnesemia occurred approximately 4 weeks after cetuximab discontinuation.
  
  
  CONCLUSIONS
  Severe hypomagnesemia is a frequent side effect of cetuximab therapy. Treatment of hypomagnesemia requires frequent intravenous magnesium supplementation and can be associated with significant patient inconvenience and an increased risk of venous access-related complications. Intermittent cetuximab schedules need to be investigated in order to reduce the frequency and severity of hypomagnesemia.
authors.affiliation: Department of Medicine, Roswell Park Cancer Institute, Buffalo, NY 14263, USA. marwan.fakih@roswellpark.org
authors.forename: Marwan G
authors.initials: MG
authors.lastname: Fakih
authors.forename: Gregory
authors.initials: G
authors.lastname: Wilding
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Lombardo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000009:adverse effects*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000009:adverse effects*; D000068818:Cetuximab; D015179:Colorectal Neoplasms / Q000188:drug therapy*; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000139:chemically induced; D007008:Hypokalemia / Q000139:chemically induced; D008274:Magnesium / Q000008:administration & dosage / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D008274:Magnesium; D000068818:Cetuximab