Administration of narcotics in cancer pain

Cancer pain can be successfully managed with oral or parenteral narcotics in 80% of patients, if those factors that magnify pain perception are also controlled. Pain from any source can be made worse and pain tolerance impaired by depression, regression, intolerance to stress, and/or recurrent withdrawal, all of which require attention and management. Those patients whose cancer pain is still intractable may benefit from a procedure to interrupt pain pathways. Such procedures have become far less common since the introduction of chronic administration of intraspinal narcotics. The subarachnoid route is preferable to the epidural route because it is less likely to result in catheter failure and because much smaller doses can be used, with less systemic effect. In addition, tolerance can be managed more readily by readjustment of dose with the subarachnoid route, and there is no greater incidence of complications. Intraventricular narcotics can be considered in patients whose spinal canal does not allow catheter placement, at approximately 1/10th the spinal dose requirement.