title: Antibiotics and azathioprine for the treatment of perianal fistulas in Crohn's disease.
abstract: BACKGROUND
  Antibiotics and thiopurines have been employed in the management of fistulizing Crohn's disease, although evidence of their efficacy is rare.
  
  
  OBJECTIVE
  To evaluate, in a prospective, open-label study, the influence of antibiotics and azathioprine on the clinical outcome of perianal fistulas in patients with Crohn's disease.
  
  
  METHODS
  Fifty-two patients entered the study, starting with an 8-week regimen of ciprofloxacin (500-1000 mg/day) and/or metronidazole (1000-1500 mg/day). Seventeen patients had already received daily azathioprine (2-2.5 mg/kg) at enrollment, whereas in 14 patients azathioprine was initiated after 8 weeks of antibiotic treatment. Outcome was evaluated by Fistula Drainage Assessment and the Perianal Disease Activity Index at weeks 8 and 20.
  
  
  RESULTS
  Overall, 26 patients (50%) responded to antibiotic treatment, with complete healing in 25% of patients at week 8. The Perianal Disease Activity Index decreased significantly from 8.4 +/- 2.9 to 6.0 +/- 4.0 (P < 0.0001). At week 20, the outcome was assessed in 49 patients (94%), 29 of whom (59%) had received azathioprine. Response was noted in 17 of the 49 patients (35%), with complete healing in nine patients (18%). Patients who received azathioprine were more likely to achieve a response (48%) than those without immunosuppression (15%) (P = 0.03). The Perianal Disease Activity Index was closely associated with treatment response and perianal disease activity.
  
  
  CONCLUSIONS
  Antibiotics are useful to induce a short-term response in perianal Crohn's disease, and may provide a bridging strategy to azathioprine, which seems to be essential for the maintenance of fistula improvement.
authors.affiliation: Department of Internal Medicine IV, Division of Gastroenterology and Hepatology, Institute of Tumour Biology, University Hospital, Vienna, Austria.
authors.forename: C
authors.initials: C
authors.lastname: Dejaco
authors.forename: M
authors.initials: M
authors.lastname: Harrer
authors.forename: T
authors.initials: T
authors.lastname: Waldhoer
authors.forename: W
authors.initials: W
authors.lastname: Miehsler
authors.forename: H
authors.initials: H
authors.lastname: Vogelsang
authors.forename: W
authors.initials: W
authors.lastname: Reinisch
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents; D001004:Anus Diseases / Q000188:drug therapy*; D001379:Azathioprine / Q000008:administration & dosage*; D002939:Ciprofloxacin / Q000008:administration & dosage; D003424:Crohn Disease / Q000188:drug therapy*; D004359:Drug Therapy, Combination / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000008:administration & dosage; D008875:Middle Aged; D011446:Prospective Studies; D012003:Rectal Fistula / Q000188:drug therapy*; D012008:Recurrence; D016896:Treatment Outcome
chemical_list: D000276:Adjuvants, Immunologic; D000900:Anti-Bacterial Agents; D008795:Metronidazole; D002939:Ciprofloxacin; D001379:Azathioprine