Intraspinal opiates for treatment of intractable pain in the terminally ill cancer patient.

The discovery of opiate receptors and then their endogenous ligands in 1974 (Snyder et al., 1974) has elucidated a vast pharmacology of opiates providing a basis for their diverse clinical applications. With the awareness of quality of life as a primary goal in terminal cancer patients, widespread attention has been drawn to the direct delivery of long-term intraspinal analgesics to cancer patients for who all medical pain control regimens have failed (Coombs & Saunders, 1974). Intraspinal administration of opiates and nonopiate analgesics is not only appealing on theoretical grounds but provides a minimally invasive method to insure otherwise unobtainable pain relief while eliminating obtundation and systemic side-effects associated with conventional therapy (Cobb et al., 1984; Harbaugh et al., 1982; Leavens et al., 1982; Malone et al., 1985; Onofrie et al., 1981; Poletti et al., 1981). Although intraspinal opiates have been used in the treatment of postoperative and benign-pain syndromes (Asari et al., 1981; Cousins & Mather, 1984), in our discussion we review the basic science, current techniques and possible future improvements in spinal analgesia in the control of chronic cancer pain.