Treatment of chronic pain of malignant origin with intrathecal opiates.

The acute administration of intrathecal morphine in man results in analgesia mediated by an opiate receptor. Chronically infused intraspinal opiates have an analgetic action mediated by opiate receptors. Our data appear to indicate that the chronic administration of spinal morphine can provide pain relief for terminal cancer patients for at least 3 months, and that this effect also is mediated by an opiate receptor. There appear to be at least two classes of opiate receptors in the human and animal spinal cords which mediate analgesia. Our preliminary data suggest that, as in the animal model, DADL, a delta-ligand, shows significant activity in a morphine-tolerant spinal cord.