Double-blinded, randomized, placebo-controlled study to evaluate the effectiveness of sulphasalazine in preventing acute gastrointestinal complications due to radiotherapy

Acute radiation-induced diarrhea occurs in approximately 80% of the patients receiving pelvic radiotherapy. It is caused by gastrointestinal irritation and inflammation. Eicosanoids are thought to be one of the mechanisms of this. Sulphasalazine is an inhibitor of their synthesis in the mucosa. This randomized clinical trial was undertaken to evaluate its effect in preventing acute radiation enteritis (ARE).Prospectively, 87 patients receiving pelvic radiotherapy were randomized, in a double-blind fashion. Two tablets twice daily of sulphasalazine (500 mg) or placebo were administered orally. Patients were evaluated weekly according to diarrhea grading for the primary study endpoint and according to late effect of normal tissue-subjective objective management analytic (LENT-SOMA) criteria for the secondary endpoint during irradiation.Groups did not differ for age, gender, tumour site or irradiation procedure. Diarrhea occurred in 55 and 86% of the sulphasalazine and placebo groups, respectively (P=0.001). Gastrointestinal toxicity was seen in 80 and 93% of the sulphasalazine and placebo groups according to the maximum LENT-SOMA score (P=0.07). According to the maximum LENT-SOMA score between the two groups, significant differences in favor of sulphasalazine were found for each week.Sulphasalazine (2 g/day) was found to be effective in decreasing the symptoms of ARE.