Although the vast majority of patients with cancer pain receive effective analgesia from
standard therapy, a few patients, particularly those with neuropathic pain, continue to
experience severe pain despite large doses of systemic or intraspinal opioids. Animal
studies suggest intraspinal α2-adrenergic agonists may be effective in such cases. Eighty-
five patients with severe cancer pain despite large doses of opioids or with therapy-limiting
side effects from opioids were randomized to receive, in a double-blind manner, 30 gmg/h …

Intrathecally administered clonidine has been reported to produce analgesia in cancer
patients tolerant to intrathecal opiates. To assess the efficacy, safety, and appropriate dose
of epidurally administered clonidine for the treatment of cancer pain, clonidine (range, 100-
900 micrograms in 100-micrograms increments) was injected in nine patients with severe,
intractable cancer pain. Clonidine produced analgesia, as measured by change in verbal
pain scores, lasting more than 6 h. Clonidine also decreased blood pressure, although this …