Abstract
A 35-year-old male with a complex gastrointestinal history and metastatic intrahepatic cholangiocarcinoma was hospitalized with intractable cancer-associated pain, unrelieved by oral opioids at escalating doses. Transdermal options were contraindicated due to ozone bath therapy. Given the poor response to previous opioid trials and concerns regarding oral absorption, sublingual buprenorphine was initiated, leading to significant improvement in functional pain control. Despite recurrent malignant bowel obstructions with intolerance to oral intake, the patient consistently maintained tolerable pain control until discharge to hospice services. This case highlights sublingual buprenorphine as an effective strategy for complex cancer pain in patients with limited analgesic routes.