High-dose loperamide in the treatment of 5-fluorouracil-induced diarrhea in colorectal cancer patients.

Thirty-seven colorectal cancer patients with grade 1-4 diarrhea (NCICTC) caused by chemotherapy with 5-FU-containing regimens, received oral loperamide at the initial dose of 4 mg followed by 4 mg every 8 h (total dose 16 mg/24 h). Twenty-five patients (69\%) were diarrhea-free and were considered to be treatment responders. Eight-four percent of the patients with grade 1 or 2 diarrhea achieved a response, but only 52\% of those with grade 3-4 diarrhea. These data seem to suggest that high-dose loperamide is effective in patients with moderate diarrhea and can be regarded as the treatment of choice. The patients with more severe diarrhea did not respond so well, and should, perhaps, be given first-line treatment with more effective drugs, such as somatostatin analogues (e.g., octreotide).