Intrathecal baclofen in pain management.

Baclofen is a GABA(B) agonist that is administered spinally via an implanted drug delivery device to treat spasticity. It has been shown to have powerful antinociceptive effects in experimental animal models at doses that produce little or no motor-blocking effects but has rarely been used as a spinal analgesic agent in patients without spasticity. Several studies have indicated that intrathecal baclofen provides relief of central pain in patients with spasticity. To date, only 3 studies have shown it to be effective in patients with peripheral nociceptive or neuropathic pain mechanisms. Combinations of baclofen and morphine or clonidine are more effective than each drug alone in clinical as well as animal studies.