Kehrer, D.F., Sparreboom, A., Verweij, J., de Bruijn, P., Nierop, C.A., van de Schraaf, J., … De Jonge, M.J. (2001). Modulation of irinotecan-induced diarrhea by cotreatment with neomycin in cancer patients. Clinical Cancer Research, 7(5), 1136–1141.

To evaluate irinotecan disposition and pharmacodynamics in the presence and absence of the broad-spectrum antibiotic neomycin

Patients experiencing grade 2 or higher diarrhea after receiving irinotecan alone (350 mg/m² every 3 weeks) received the same dose combined with 1,000 mg oral neomycin three times per day continuously from 2 days prior to 5 days after the second course.

The study reported on 20 patients with advanced colorectal cancer receiving CPT-11 (350 mg/m² every 3 weeks).

This was a nonrandomized trial. Patients acted as their own controls.

Presence of more than 4 stools per day and duration (measured in days) of diarrhea were recorded.

• Nine patients developed grade 2 diarrhea in the first chemotherapy course and were then given neomycin as cotreatment in the second course of chemotherapy.
• No significant effect was found on hematological toxicity (p > 0.05), but diarrhea improved in six out of seven patients (p = 0.033).

Findings indicate that bacterial B-glucorinidase plays a crucial role in irinotecan-induced diarrhea without affecting enterocycling and systemic SN-38 levels.
 

This was an extremely small pilot study.