Clarithromycin attenuates cyclophosphamide-induced mucositis in mice

No universally recognized agent is available for prophylaxis or therapy of mucositis induced by chemotherapy or chemo-radiotherapy. The effect of clar ithromycin on the severity of mucositis induced by cyclophosphamide was inv estigated using a mouse model. Four cross-sections of small intestine (leve ls A, B, C, and D) were taken at equivalent intervals at day 5 after cyclop hosphamide (400 mg kg(-1)) administration. The sections were stained with h aematoliylin and eosin, and were graded for the degree of mucositis histolo gically. At section level B, the number of mice with no mucositis (grade 0) in the clarithromycin group was significantly greater than that in the cef triaxone group (P < 0.05). At levels B and C, the number of mice with no mu cositis (grade 0) in the clarithromycin group was significantly greater tha n that in the normal saline (NS) group (P < 0.05). At level C, the number o f mice with grade 2 mucositis in the ceftriaxone group was significantly gr eater than that in the NS group (P < 0.05). When the number of sections at all levels were analyzed together, the number of mice with no mucositis (gr ade 0) in the clarithromycin group was significantly greater than that in t he ceftriaxone and NS groups (P < 0.05). The present observation suggests t hat clarithromycin and ceftriaxone attenuates and aggravates cyclophosphami de-induced mucositis. It prompts clinical trials in bone marrow transplant (BMT) recipients receiving cyclophosphamide for conditioning, and reconside ration in the use of ceftriaxone in the treatment of neutropenic fever in B MT recipients. (C) 2000 Academic Press.