AIM: To analyze sex differences in adverse drug reactions (ADR) to the immune suppressive medication in inflammatory bowel disease (IBD) patients. METHODS: All IBD patients attending the IBD outpatient clinic of a referral hospital were identified through the electronic diagnosis registration system. The electronic medical records of IBD patients were reviewed and the files of those patients who have used immune suppressive therapy for IBD, i.e., thiopurines, methotrexate, cyclosporine, tacrolimus and anti-tumor necrosis factor agents (anti-TNF); infliximab (IFX), adalimumab (ADA) and/or certolizumab, were further analyzed. The reported AD RESULTS: In total, 1009 IBD patients were identified in the electronic diagnosis registration system. Out of these 1009 patients, 843 patients were eligible for further analysis. There were 386 males (46%), mean age 42 years (range: 16-87 years) with a mean duration of the disease of 14 years (range: 0-54 years); 578 patients with Crohn's disease, 244 with ulcerative colitis and 21 with unclassified colitis. Seventy percent (586 pts) of patients used any kind of immune suppressive agents at a ce CONCLUSION: Treatment with anti-TNF antibodies is accompanied by sexual dimorphic profile of ADR with female patients being more at risk for allergic reactions and subsequent discontinuation of the treatment. (C) 2012 Baishideng. All rights reserved.