title: Investigation of a possible interaction between ciprofloxacin and cyclosporine in renal transplant patients.
abstract: BACKGROUND
  Bacterial infection is a common complication during the first few months after renal transplantation. Ciprofloxacin, a fluoroquinolone broad-spectrum antibiotic, is used frequently in treating infections in the early posttransplant period. Evidence from in vitro studies has suggested that ciprofloxacin can antagonize the cyclosporine (CsA)-dependent inhibition of interleukin-2 production. Such an effect in renal transplant patients could antagonize the immunosuppressive activity of CsA and lead to rejection of the graft.
  
  
  METHODS
  To investigate the possibility of a pharmacodynamic interaction between ciprofloxacin and CsA, we conducted a case-control study in 42 patients who had received a kidney transplant and who were prescribed ciprofloxacin in the first 1-6 months after transplantation and in their matched controls (two per case) who did not receive ciprofloxacin during the study period.
  
  
  RESULTS
  There was a twofold greater incidence (P=0.008) of ciprofloxacin use at 1-3 months (65%) than was observed at 4-7 months (35%) after transplantation. The proportion of cases experiencing at least one episode of biopsy-proven rejection 1-3 months posttransplant (45%) was significantly greater (P=0.004) than that of controls (19%). Furthermore, there was a marked increase (P<0.001) in the incidence of rejection temporally associated with ciprofloxacin use among cases (29%) compared with that experienced by the controls (2%).
  
  
  CONCLUSIONS
  The possibility that ciprofloxacin increases rejection rates in renal transplant patients may be of clinical importance and therefore warrants further investigation.
authors.affiliation: Faculty of Pharmaceutical Sciences, University of British Columbia, and Department of Pharmacy, British Columbia's Children's and Women's Hospitals, Vancouver, Canada.
authors.forename: R E
authors.initials: RE
authors.lastname: Wrishko
authors.forename: M
authors.initials: M
authors.lastname: Levine
authors.forename: D R
authors.initials: DR
authors.lastname: Primmett
authors.forename: S
authors.initials: S
authors.lastname: Kim
authors.forename: N
authors.initials: N
authors.lastname: Partovi
authors.forename: S
authors.initials: S
authors.lastname: Lewis
authors.forename: D
authors.initials: D
authors.lastname: Landsberg
authors.forename: P A
authors.initials: PA
authors.lastname: Keown
mesh_terms: D000890:Anti-Infective Agents / Q000627:therapeutic use*; D001706:Biopsy; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D002939:Ciprofloxacin / Q000627:therapeutic use*; D016572:Cyclosporine / Q000037:antagonists & inhibitors* / Q000097:blood / Q000627:therapeutic use*; D004347:Drug Interactions; D005260:Female; D006084:Graft Rejection / Q000453:epidemiology* / Q000276:immunology / Q000473:pathology; D006801:Humans; D007166:Immunosuppressive Agents / Q000037:antagonists & inhibitors / Q000097:blood / Q000627:therapeutic use*; D016030:Kidney Transplantation / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012086:Reoperation; D012189:Retrospective Studies
chemical_list: D000890:Anti-Infective Agents; D007166:Immunosuppressive Agents; D002939:Ciprofloxacin; D016572:Cyclosporine