Intraspinal Narcotic Tolerance: Preliminary Experience with Continuous Bupivicaine HCL Infusion via Implanted Infusion Device

Abstract

Spinal opiate receptor tolerance is the major limitation of continuous intraspinal narcotic analgesia delivered by implanted reservoir pump. Six intractable pain patients receiving continuous epidural morphine were given trials of low dose bupivicaine HCL in order to assess the effects on implanted reservoir function, analgesia, and safety. Daily infusion of 2.6-18.8 mg bupivicaine HCL had no consistent effect on flow rates. Subjectively, three patients had at least partial relief of pain while their intraspinal morphine doses were weaned. No sympathectomy was appreciated at these doses. The future of continuous intraspinal analgesia might require further advances in implantable infusion pump technology to allow manipulation of both daily infusion doses and multiple intraspinal analgesics. Further study is needed to assess the safety and effectiveness of higher continuous intraspinal bupivicaine doses for chronic pain relief.

Intrathecal Hydromorphone for Chronic Nonmalignant Pain: A Retrospective Study

“…Ultimately, however, analgesic response diminished and bupivacaine was discontinued. Similar results have been reported by Hassenbusch and others [39,40]. Finally, in two patients with neuropathic pain resulting from arachnoiditis and sciatic neuropathy response to combination intraspinal morphine/clonidine (50 or 100 μg/day) was evaluated [41–43].…”

Operating Principles and Clinical Implications of Constant Flow Pumps

“…Since these early studies, numerous investigators have shown safety and efficacy with intrathecal administration of morphine for the treatment of chronic pain (10–13). Other drugs such as clonidine, hydromorphone, bupivacaine, and analgesic peptides have been used in addition to or as alternatives to morphine infusion (14–16). In the case of narcotic infusion for pain control, the importance of neither under‐ nor overdosing is obvious.…”