Pain control with morphine for vertebral metastases and sciatica in advanced cancer patients.

Morphine was administered to 56 advanced cancer patients; of that number spinal metastases had induced bone pain in 28 and malignant tumors had induced sciatica in 28. The sciatica was caused in 16 patients by direct invasion of the sacral plexus, in four by lumbar bone metastases, and in eight by pelvic bone metastases. Spinal bone pain was controlled adequately with morphine. However, sciatica required larger dosages of morphine than did bone pain. Among the group with sciatica, rectal cancer patients needed larger dosages of morphine than the other cancer patients. Even with high doses of morphine, it was occasionally difficult to control neuropathic pain of the sciatic nerve caused by intrapelvic cancer.