Effect of N-acetylcysteine on remission maintenance in patients with ulcerative colitis: A randomized, double-blind controlled clinical trial.

Background: The use of antioxidant agents is suggested as a complementary therapy in UC patients for the prevention of flares. Considering the potent antioxidant activity of N-acetylcysteine (NAC), in the present study we aimed to assess the effect of this supplement on remission maintenance in patients with ulcerative colitis (UC).

Methods: In the present double-blind randomized controlled clinical trial, 168 volunteer UC patients who were on high dose corticosteroid and Mesalamine for flare-up management, were recruited. The patients received 800 mg NAC or placebo for 16 weeks. Simultaneously, the prednisolone dose was tapered. The patients were followed up six more weeks post-intervention. The primary efficacy of the treatment was remaining in remission. The secondary outcomes were the endoscopic relapse, serum level of hs-CRP, hemoglobin, and fecal calprotectin level.

Results: During 22 weeks follow up, 25 patients experienced relapses, six of them were in the NAC group and 19 of them were in the placebo group. There was a significant difference between the NAC and placebo groups regarding the relapse-free period (P = 0.007). Compared with the NAC group, significantly more patients in the placebo group had an endoscopic relapse (p < 0.001). At the end of the intervention period (16 weeks) and 6 weeks post-intervention, the mean fecal calprotectin, serum erythrocyte sedimentation rate, and hs-CRP levels were significantly lower in the NAC group compared with the placebo group (p < 0.05).

Conclusion: The findings indicated that NAC had a significantly more positive effect on the maintenance of remission compared with placebo in UC patients that were in the steroid-tapering phase of therapy.