Drug delivery systems for epidural administration of opioids.

From a practical and cost-effective viewpoint, the bolus administration of opiates via an implanted epidural catheter and portal injection system offers improved pain control for a good percentage of patients suffering pain secondary to cancer who are not responding to oral analgesia. However, considerable research is required into the mechanism of action, drug of choice, and optimal drug delivery system for the epidural administration of opiate drugs. Although this system is still in its infancy, it would be fair to say that it is one of the most significant advances for the control of pain in patients with cancer this century.