Intrathecal drug therapy for chronic pain: from basic science to clinical practice.

SYSTEMIC analgesics and conservative therapies are effective in controlling chronic pain for the majority of patients. However, many other patients, such as those with advanced head and neck carcinoma and those with neuropathic pain, require more aggressive therapy to directly modulate pain transmission in the central nervous system. Reversible methods of aggressive therapy in the spinal cord include electrical stimulation procedures and intrathecal delivery of analgesics by implanted pumps, both of which are finding ever-expanding roles in pain control. Of these, long-term intrathecal drug therapy is likely to show the largest near-term expansion because the numbers of agents approved for this route of administration are likely soon to increase substantially. Moreover, drug therapy itself will change as treatments using microsome drug encapsulation and novel suspension media are introduced. Further on the clinical horizon is intrathecal cell implantation for the relief of chronic pain. The goal of this review is to update the reader regarding each of these pending advances in intrathecal drug therapy for chronic pain. Present and Future Intrathecal Analgesics