Purpose: Bone metastasis is one of the major causes of cancer-related pain, and not all bone cancer pain can be effectively treated. Recently, a mouse model of bone cancer pain was introduced. To test the analgesic effects of nonsteroidal antiinflammatory drugs on bone cancer pain, the authors examined the effects of oral administration of a cyclooxygenase-1 (COX-1) selective inhibitor (SC560), a COX-2 selective inhibitor (celecoxib), and a nonselective COX inhibitor (indomethacin) on bone cancer pain and compared these effects to the effect of orally administered acetaminophen and morphine.
Methods: An animal model of bone cancer pain was induced by injecting osteolytic murine sarcoma cells in the mouse femur. Drugs were administered orally 2 weeks after tumor-cell implantation, and the level of bone cancer pain was assessed 30, 60, 90, 120, and 180 min after drug administration.
Results: Oral administration of acetaminophen, indomethacin, and morphine, but not of SC560 or celecoxib, produced an analgesic effect on bone cancer pain. Co-administration of a subanalgesic does of morphine with acetaminophen enhanced the analgesic effect of acetaminophen.
Conclusion: These data suggest that bone cancer pain is effectively treated by oral administration of indomethacin, acetaminophen, and morphine and that the co-administration of acetaminophen and an opioid provides a beneficial effect when treating of bone cancer pain.