title: Metformin-induced hemolytic anemia.
abstract: OBJECTIVE
  To report a rare side effect of metformin, an oral antidiabetic drug that is used for the treatment of type 2 diabetes mellitus.
  
  
  METHODS
  A 17-year-old boy was hospitalized for receiving acute lymphoblastic leukemia treatment that was composed of vincristine, L-asparaginase, daunorubicin, and prednisone. Hyperglycemia was determined without any clinical sign and metformin was started for steroid-induced insulin resistance. On the second day of metformin treatment, the patient's hemoglobin level decreased, and a direct Coombs test was positive for immunoglobulin G but negative for complement. An indirect Coombs test was negative. The glucose-6-phosphate dehydrogenase level was within the normal range. Drug-induced hemolytic anemia was suspected and metformin was discontinued. The jaundice gradually disappeared and there was no requirement for red blood cell transfusions.
  
  
  CONCLUSIONS
  This case showed that physicians should be aware of the potential side effect of metformin although it is infrequent.
authors.affiliation: Ankara Children's Hematology and Oncology Hospital, Ankara, Turkey.
authors.forename: Serap
authors.initials: S
authors.lastname: Kirkiz
authors.forename: Nese
authors.initials: N
authors.lastname: Yarali
authors.forename: Ozlem
authors.initials: O
authors.lastname: Arman Bilir
authors.forename: Bahattin
authors.initials: B
authors.lastname: Tunc
mesh_terms: D000293:Adolescent; D000743:Anemia, Hemolytic / Q000139:chemically induced*; D005954:Glucosephosphate Dehydrogenase / Q000097:blood; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D006943:Hyperglycemia / Q000188:drug therapy*; D007004:Hypoglycemic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D008687:Metformin / Q000009:adverse effects* / Q000627:therapeutic use; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy
chemical_list: D006454:Hemoglobins; D007004:Hypoglycemic Agents; D008687:Metformin; D005954:Glucosephosphate Dehydrogenase