3060 Octreotide Use in Chronic Diarrhea Post Capecitabine Treatment

Abstract

INTRODUCTION: Diarrhea is a known common side effect of chemotherapy, and is commonly associated with Capecitabine which was developed to increase systemic tolerability with tumor-specific conversion to 5-FU. Early onset diarrhea and mild to moderate diarrhea have been noted to occur in colorectal cancer patients on Capecitabine. Chemotherapy induced diarrhea (CID) can be life-threatening in severe cases due to resulting electrolyte imbalances, metabolic acidosis, and renal failure. Loperamide is the first line treatment for CID with octreotide being second-line treatment when patients fail to respond to loperamide within 48 hours. However, in cases of severe CID it is recommended that octreotide be initiated as first line therapy. CASE DESCRIPTION/METHODS: A 70 year old male with a history of poorly differentiated mucinous adenocarcinoma of the colon status post capecitabine presented to the ED with complaints of diarrhea. The patient initially presented to the oncology office with reported diarrhea, which was untreated at that time as diarrhea was suspected to be self limiting since he had stopped chemotherapy two days prior. When diarrhea did not abate he was admitted for diarrhea with dehydration. During admission octreotide was initiated since diarrhea did not abate on Imodium and loperamide. One week into admission, the patient developed metabolic acidosis (bicarb 8.6) and minimal resolution of diarrhea while on octreotide. Due to continued soft to loose frequent stools, the patient's octreotide dose was increased to 200 mcg every 8 hours and patient was placed back on scheduled loperamide. He was discharged on 30 mg long acting subcutaneous octreotide and as needed loperamide. He subsequently received 2 additional doses due to continued diarrhea before representing to the ED three months later for worsening diarrhea. DISCUSSION: This case demonstrates the complications that can arise from delayed octreotide treatment in diarrhea status post capecitabine treatment for colon cancer. 5-FU based chemotherapy has been known to result in potentially life-threatening mucosal toxicity. Literature review has shown that octreotide has improved overall response when compared to loperamide in resolution of CID diarrhea. This patient's poor inpatient response to anti-diarrheal agents highlights the importance of early CID management.