A controlled evaluation of an allopurinol mouthwash as prophylaxis against 5‐fluorouracil‐induced stomatitis

Pursuant to a promising report suggesting that an allopurinol mouthwash could have a protective effect against 5‐fluorouracil (5‐FU)‐induced stomatitis, the authors performed a randomized, placebo‐controlled, double‐blind, crossover study. Seventy‐seven patients, receiving their first 5‐day course of chemotherapy with 5‐FU ± leucovorin, were assigned to use a mouthwash containing 20 mg of allopurinol or a placebo. The mouthwash was administered every hour for four doses commencing with each chemotherapy dose. The severity of subsequent mucositis was graded (on a 0‐4 scale) by the attending physician and also by a patient‐completed questionnaire. There was trend toward less mucositis in the placebo group with mean physician‐judged mucositis scores of 1.3 for placebo and 1.8 for allopurinol (P = 0.07) and mean patient‐judged mucositis scores of 1.5 for placebo and 1.9 for allopurinol (P = 0.15). There were no substantial differences in mucositis attributable to the two mouthwashes in the patients who crossed‐over on their second cycle of chemotherapy. These data demonstrate that the tested allopurinol mouthwash regimen does not offer any protective effect against 5‐FU‐induced mucositis.