Long-term intrathecal infusion of morphine and morphine/bupivacaine mixtures in the treatment of cancer pain: a retrospective analysis of 51 cases.

A retrospective analysis of 51 patients with cancer pain treated with a continuous i.t. morphine infusion through a tunnelled percutaneous catheter was undertaken. Because of insufficient pain relief with morphine only, 17 of these patients received a morphine/bupivacaine mixture. Pain relief subsequently improved significantly in 10 patients and a moderate improvement was present in 4 patients. An additional analgesic effect of bupivacaine was not shown in 3 patients with clinical signs of severe mental depression. Bupivacaine-induced side effects were absent below a daily dosage of 30 mg by continuous infusion. In all patients a gradual dose increment was observed. No serious complications, neurologic sequelae or meningitis occurred. It is concluded that long-term i.t. infusion of morphine through a tunnelled catheter can provide adequate pain relief in cancer patients with an acceptable risk-benefit ratio. The effects of long-term intrathecal co-administration of local anesthetics, especially bupivacaine, await further prospective evaluation.