title: Cisplatin-induced hyponatremia in malignancy: comparison between brand-name and generic formulation.
abstract: BACKGROUND
  Widespread use of generic drugs is considered to be indispensable if reductions in total health care costs are to be achieved, but the market share of such drugs remains low. In general, generic drugs have the same active ingredients as brand-name drugs, but this is not always the case. Thus, toxicity profiles may vary when brand-name and generic drugs are compared. We retrospectively investigated the incidence of hyponatremia in patients receiving brand-name cisplatin (CDDP) and a generic counterpart thereof.
  
  
  METHODS
  We reviewed the medical records of patients treated with brand-name CDDP (n=53) and a generic formulation (n=26), and compared the incidences of hyponatremia and renal toxicity. Toxicities were graded using the Common Terminology Criteria for Adverse Events, version 4.0. Differences between groups were evaluated using the Student's t-test, and the odds ratio for hyponatremia was estimated via logistic regression analysis.
  
  
  RESULTS
  Serum creatinine levels after chemotherapy increased significantly in both the brand-name and generic CDDP groups; no significant difference was evident between the two groups. Hyponatremia of grade 3 or above developed in 30.7% of the generic CDDP group compared to 15.1% of the brand-name CDDP group (P=0.011). Multivariate analysis showed that the use of generic CDDP increased the incidence of hyponatremia (odds ratio =5.661, 95% confidence interval =1.403-22.839; P=0.015).
  
  
  CONCLUSIONS
  Oncologists should be aware that use of a generic CDDP might be associated with more hyponatremia than would use of brand-name CDDP.
authors.affiliation: Department of General Internal Medicine 4, Kawasaki Hospital, Kawasaki Medical School, Okayama, Japan ; Department of Hematology, Oncology and Respiratory Medicine, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Ochi
authors.affiliation: Department of General Internal Medicine 4, Kawasaki Hospital, Kawasaki Medical School, Okayama, Japan.
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Yamane
authors.affiliation: Department of Hematology and Oncology, Okayama University Hospital, Okayama, Japan.
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Hotta
authors.affiliation: Department of Pharmacy, Kawasaki Hospital, Kawasaki Medical School, Okayama, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Fujii
authors.affiliation: Department of Hematology, Oncology and Respiratory Medicine, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan ; Department of Clinical Pharmaceutics, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Hideko
authors.initials: H
authors.lastname: Isozaki
authors.affiliation: Department of General Internal Medicine 4, Kawasaki Hospital, Kawasaki Medical School, Okayama, Japan ; Department of Hematology, Oncology and Respiratory Medicine, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Honda
authors.affiliation: Department of General Internal Medicine 4, Kawasaki Hospital, Kawasaki Medical School, Okayama, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Yamagishi
authors.affiliation: Department of Respiratory Medicine, Okayama University Hospital, Okayama, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Kubo
authors.affiliation: Department of Hematology, Oncology and Respiratory Medicine, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan ; Department of Hematology and Oncology, Okayama University Hospital, Okayama, Japan.
authors.forename: Mitsune
authors.initials: M
authors.lastname: Tanimoto
authors.affiliation: Department of Respiratory Medicine, Okayama University Hospital, Okayama, Japan.
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Kiura
authors.affiliation: Department of General Internal Medicine 4, Kawasaki Hospital, Kawasaki Medical School, Okayama, Japan.
authors.forename: Nagio
authors.initials: N
authors.lastname: Takigawa
mesh_terms: D000328:Adult; D000368:Aged; D002626:Chemistry, Pharmaceutical; D002945:Cisplatin / Q000009:adverse effects* / Q000627:therapeutic use; D016568:Drugs, Generic; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D055553:Prescription Drugs; D012044:Regression Analysis; D012189:Retrospective Studies
chemical_list: D016568:Drugs, Generic; D055553:Prescription Drugs; D002945:Cisplatin
keywords: brand-name; cisplatin; generic drug; hyponatremia