Antibiotics and azathioprine for the treatment of perianal fistulas in Crohn's disease.
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.
Dejaco
C
C
Department of Internal Medicine IV, Division of Gastroenterology and Hepatology, Institute of Tumour Biology, University Hospital, Vienna, Austria.
Harrer
M
M
Waldhoer
T
T
Miehsler
W
W
Vogelsang
H
H
Reinisch
W
W
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
D000276:Adjuvants, Immunologic; D000900:Anti-Bacterial Agents; D008795:Metronidazole; D002939:Ciprofloxacin; D001379:Azathioprine