Adverse events observed during infliximab therapy – a national multicenter study

Biological therapy is widely used in the treatment of severe Crohn's disease (CD), but the profile of the adverse events of these new agents has not yet been really recognized.

Aim: A retrospective assessment of the frequency and severity of the side-effects observed during treatment of CD with infliximab, a chimerical TNF-alpha blocker.

Patients and methods: 129 patients (diagnosis: 124 CD, 5 ulcerative colitis (UC); female/male ratio: 79/50; mean age: 36, 17–72 years) at three Hungarian centers were treated with infliximab. The total number of infusions during the period from March 2000 to January 2006 was 424 (mean: 3.28, 1–14). The indications were perianal fistulae in 78 cases, continuous activity in 29 cases, both in 14 cases, and metastatic skin lesions in 3 cases; therapy refractory UC were in 5 cases. Adverse events were categorized according to the time period (acute: within 2 hours of infusion, early: within 48 hours; or late: within 3 months), to the relationship of the drug (unlikely, possible or probable) and to the severity (mild, moderate or severe).

Results: An acute, typical allergic infusion reaction was observed on 12 occasions, i.e. in 2.8% of all 424 infusions and in 9.3% of the patients. The relationship was probable and the severity was mild in all 12 cases. Early adverse events were rare (0.9% of the infusions) and mild. Late adverse events were relatively frequent; complications were observed in 15.5% of the patients within 3 months after the therapy, some of them were probably connected with the drug and the severity was life-threatening.

Conclusions: While infusion reactions are infrequent and mild complications of infliximab therapy, the late adverse events may be more severe and require a strict post-treatment follow-up of the patients.