Long-term outcomes during treatment of chronic pain with intrathecal clonidine or clonidine/opioid combinations.

To evaluate the effectiveness of intrathecal clonidine or clonidine/opioid admixture for the treatment of chronic pain states, a retrospective chart audit of 15 patients seen by the Pain Medicine and Neurosurgical Services was performed. Subjects included 9 men and 6 women aged 26-86 years. Diagnoses included complex regional pain syndrome, neuropathic pain, and cancer pain. All patients received a trial of single-shot and/or short-term infusion of clonidine. Those reporting a significant reduction in pain, or at least 50% reduction in their visual analog scale (VAS), received long-term therapy. Intrathecal clonidine as a single-shot dose, infusion, or as intrathecal polytherapy did not improve VAS scales from pre-treatment values in 5 patients. Ten patients reported significant pain relief or >50% decrease in VAS scores with the initial trial and received long-term therapy. Two received clonidine alone for 7-11 months before the therapy failed; others failed after just a few days. Seven of eight initially responded to clonidine alone (75-950 microg/day) before failing and requiring a second drug. Three received hydromorphone (200-8000 microg/day) and four morphine (0.15-15 mg/day) with clonidine. Four patients then failed 2-drug therapy (duration 6-21 months). Two continue with intrathecal clonidine/hydromorphone (duration 19-29 months) and 1 with clonidine/morphine (duration 21 months). After initiation of intrathecal clonidine, one patient reported good relief with clonidine/morphine until his death 5 months later. In this population, intrathecal clonidine was of limited utility for most patients. It may be of benefit for subset(s) of patients, but in our experience, duration of relief is typically <18 months.