1. 2008;11;S89-S104Intrathecal Drug Delivery
   
   Howard S. Smith, MD, Timothy R. Deer, MD, Peter S. Staats, MD, Vijay Singh, MD, Nalini Sehgal, MD, and Harold Cordner, MD.

Intrathecal analgesia has emerged as a key therapeutic option for pain relief for patients who have failed other treatment avenues as well as patients with adequate analgesia on high dose enteral or parenteral therapy but with unacceptable side effects. Intrethecal infusions of analgesics have been increasingly utilized since the later 1980s for the treatment of persistent pain.

The purpose of this review is to provide research based clinical insight regarding the safe and appropriate use of the intrathecal infusion modality.

Long-term intrathecal infusion analgesia or long-term intrathecal or long-term intrathecal analgesic therapy has significantly progressed over the past 25 years. The evidence for implantable intrathecal infusion systems is strong for short-term improvement in pain of malignancy or neuropathic pain. The evidence is moderate for long-term management of persistent pain. Reasonably strong evidence exists for the use of ong-term intrathecal analgesic therapy in alleviation of cancer pain; however, the evidence supporting long-term efficacy in persistent noncancer pain is less convincing.

Future studies are needed to better define the role of long-term intrathecal analgesic therapy in persistent pain, especially with respect to which pain conditions or subpopulations of patients are most responsive to ong-term intrathecal analgesic therapy, and which agents or combination of agents are most appropriate for which pain conditions or subpopulations of patients. Novel combinations of intrathecal analgesics such as clonidine and gabapentin deserve future study.

The current body of literature supports the use of intrathecal agents for the treatment of moderate or severe pain related to cancer and noncancer origins. Further clinical studies are needed to evaluate the efficacy and safety of new intrathecal drugs, the complications related to these devices, and the proper selection of patients to receive these treatments.