Intrathecal betamethasone for cancer pain in the lower half of the body: a study of its analgesic efficacy and safety.

BACKGROUND Sufficient analgesia for cancer pain is sometimes difficult to achieve with conventional treatments. We aimed at investigating the analgesic efficacy and safety of intrathecal betamethasone in patients with uncontrollable cancer pain. METHODS Betamethasone 1 mg mixed with saline was injected into the lumbar intrathecal space once a week in 10 patients with persistent cancer pain in the lower half of the body. During the 4-week study period, the analgesic efficacy and adverse effects related to intrathecal betamethasone were observed. RESULTS Long-lasting analgesia (mean numerical pain score < or = 5) for 7 days, after immediate analgesia within 10 min, was obtained without the need to increase the morphine dose in 5 of 10 patients. In almost all of the patients, not only pain, but also uncomfortable symptoms were improved. Adverse effects related to neurotoxicity of intrathecal betamethasone, such as sensory and motor dysfunctions, were not observed in any patients. CONCLUSION When conventional cancer pain treatments are not successful, intrathecal betamethasone may be useful, as it probably induces long-lasting analgesia without adverse effects and improves activities of daily living, especially in patients with vertebral bone metastases.