Mechanisms of action of intrathecal medications.

Intrathecal delivery of medications for the management of chronic pain syndromes reflects a modern targeted delivery system with the potential for even greater efficacy than is outlined in Tables 1 and 2. The twentieth century ushered in the development of parenteral approaches of medical therapy for chronic pain and other diseases that were superior to the traditional oral delivery methods known in the preceding century. Targeted drug delivery represents a significant advancement in the treatment of patients with chronic pain and is likely be the method of choice for the twenty-first century. This method of delivery is best represented by current drug delivery systems, such as the intrathecal drug pump. Traditional pharmacologic agents will still be used in the twenty-first century; however, the development of novel compounds, transplanted tissues, and genetic engineering will likely usher in a new era of pain management, including their use as analgesics for intraspinal infusion.