Background The formation of perianal fistulas is a serious complication that affects up to 30% of patients with Cohn's disease (CD). It has been suggested that intrafistula injection of infliximab could have some potential healing benefit becoming an adjuvant therapy or an alternative when intravenous infusion is contraindicated.

Purpose The authors describe the preparation, posology, effectiveness and tolerance of infliximab syringes.

Materials and methods Our patients were a 27-year-old woman and a 30-year-old man diagnosed with CD with luminal disease control with certolizumab and adalimumab respectively but multiple perianal draining fistulas without abscesses. Both had been previously treated with infliximab but one of them had experienced an infusion reaction and the another one had relapsed. The gastroenterology physician asked our department to prepare infliximab syringes to inject into each fistula.

Results The syringes were prepared in the pharmacy service under aseptic conditions. To prepare several syringes The authors diluted a 100 mg infliximab phial with 10 mL of water for injection; 12 mL dextrose 5% were added to 2 mL of this dilution so each syringe contained 20 mg of infliximab. The contents of one syringe were injected per fistula (at the internal and external orifices and along the fistula tract). Patients were treated under general anaesthesia and signed an informed consent. The local injections were scheduled at weeks 0, 4, 8, 12, 16 and 20. Efficacy was assessed before the injection of the next dose in terms of remission (complete cessation of fistula drainage) and response (more than 50% reduction of the draining orifices). After the third dose (week 8) both patients had achieved a response, one without remission. No adverse effects were reported.

Conclusions Although few cases have been reported, local infliximab injections may help in fistula healing and be well tolerated even by patients for whom intravenous infusion is not suitable.