[Unwanted side-effects in using mesalazine (5-aminosalicylic acid) during radiotherapy].

In a prospective randomized placebo controlled double blind study, the prophylactic effect of mesalazine (5-aminosalicylic acid. 5-ASA) as suppositories (3 x 250 mg/day) on radiation induced proctitis during radiotherapy for prostatic carcinoma was studied. The study ended when 16 patients had been included (5-ASA: eight, placebo: eight) because of severe side effects in the 5-ASA group. 75% of patients treated with 5-ASA reported symptoms of a severe proctitis while only one patient in the placebo group had similar complaints. The application of mesalazine as suppositories is not useful in preventing radiation induced proctitis during radiotherapy of prostate carcinoma.