[A case-control study of prevention of irinotecan-induced diarrhea: the reducing side effects of irinotecan by oral alkalization combined with control of defecation].

Irinotecan and its active metabolite, SN-38, were reported to have the absorption characteristics of weakly basic drugs. Moreover, stasis of these compounds is thought to induce damage to the intestinal mucous membrane. The purpose of this report was to examine whether oral alkalization (OA) combined with control of defecation (CD) might prevent irinotecan-induced side effects. From day one of irinotecan infusion to day four, OA & CD were practiced using orally administered sodium bicarbonate, magnesium oxide, basic water, and ursodeoxycholic acid. Thirty-two lung cancer patients were treated with irinotecan in combination with cisplatin in the absence of OA & CD (Group A). Thirty-seven patients matched for background characteristics were treated with the same regimen in the presence of OA & CD (Group B). Group B had a reduced incidence of delayed diarrhea (Grade 2 < or = Group A 32.3% vs. Group B 9.4%), nausea, vomiting, and myelotoxicity, especially granulocytopenia compared with Group A. In addition, dose intensification was well-tolerated in Group B. Tumor response rates for non-small cell lung cancer were 59.3% (16/27 patients) in Group B against 38.5% (10/26 patients) in Group A. OA & CD appears to reduce the irinotecan-induced side effects, especially delayed diarrhea. Risk factors statistically associated with delayed diarrhea include advanced age and the use of irinotecan without OA & CD.