Purpose: Subcutaneous (SC) octreotide has been shown to effectively relieve chemotherapy-induced diarrhea (CID) refractory to conventional therapy but requires t.i.d. injections. A microencapsulated, long-acting formulation (LAR) of octreotide has been developed for once-monthly intramuscular (IM) dosing. Efficacy in resolving severe diarrhea and preventing further episodes of diarrhea in cancer patients was explored.
Patients and methods: Patients with advanced cancer who developed CID and failed conventional antidiarrheal therapy (loperamide + diphenoxylate-atropine) received octreotide LAR IM. The starting dose was either 20 or 30 mg with possible dose escalation from 20 to 30 mg and from 30 to 40 mg. Treatment was repeated every 28 days during chemotherapy.
Results: Complete resolution of diarrhea within 1 to 4 weeks from injection time was seen in all cases with octreotide LAR 30 mg. With a subsequent prophylactic injection once every 28 days, CID was limited to NCI grade 1. This resulted in increased patient quality of life (QOL) and allowed better patient compliance with therapy. Therapy could then be completed at full dose and on schedule after resolution of often debilitating diarrhea.
Conclusion: The ability of octreotide LAR 30 mg to speed the resolution of CID and limit further episodes of diarrhea to infrequent NCI grade 1 controlled with loperamide (prn) suggests that long-acting somatostatin homologues have the potential to be useful in the secondary prevention of diarrhea in patients undergoing chemotherapy.