Nicotine in ulcerative colitis - How does it work and how can we use it?

Ulcerative colitis is primarily a disease of nonsmokers. The risk of developing disease after cessation of smoking is 'dose-related' by pack-years, and former smokers may be at higher risk than nonsmokers. Attention has been focused on nicotine as the agent responsible for this effect. Nicotine in chewing gum and transdermal patches has been shown to improve clinical symptoms and endoscopic appearance in patients with active ulcerative colitis, although no maintenance benefit has been seen. Proposed mechanisms for the 'protective' effect of nicotine in ulcerative colitis include: (a) modulation of the humoral and cellular immune response; (b) increased production of colonic mucus; (c) decreased mucosal eicosanoid levels; (d) alteration of rectal mucosal blood flow; (e) decreased intestinal permeability; and (f) release of endogenous glucocorticoids. Investigations continue into the pathophysiology and clinical impact of nicotine and smoking in ulcerative colitis. Due to the preponderance of other serious health risks associated with these agents, ultimate risk-benefit analysis will require additional controlled outcome analyses.