Increasing numbers of patients with refractory pain are receiving intrathecal drug delivery systems (IDDS). We describe a case to illustrate the clinical manifestations and management implications of inadvertent overdose with drugs used in IDDS, including opioids, clonidine, baclofen, and local anesthetics. An IDDS patient received a bimonthly dose of intrathecal hydromorphone subcutaneously. The patient received a total of 540 mg hydromorphone into the subcutaneous pocket around the intrathecal pump. She was treated with naloxone intravenously over 12 hours, and had no major adverse sequelae. Such occurrences may happen more frequently with the expanded use of IDDS and clinicians should be prepared to take quick action. Counteracting an opioid with naloxone until the opioid is metabolized and excreted can be done safely. Inadvertent subcutaneous administration of other types of drugs could be more difficult to manage.

Neuropathic pain is commonly seen in cancer patients, either as a direct result of the malignancy or as a consequence of the treatment rendered. In recent years, methadone has been utilized in the treatment of neuropathic pain because of its additional mechanism of action as an NMDA-receptor antagonist. In this paper we discuss the etiology of neuropathic pain in cancer patients, unique properties of methadone, and prior studies on methadone in this patient population. While methadone has been established as a cheap and effective agent in treating cancer pain, specific studies are needed comparing methadone to other opioids in the management of cancer-related neuropathic pain.

The benefits of two dosing methods, patient-controlled analgesia (PCA) with morphine sulfate (MS) alone and PCA plus continuous infusion of morphine sulfate (PCA + CI) were clinically evaluated in a randomized, single-blinded study of 30 adult abdominal surgery patients. Doses were adjusted based on pain and sedation ratings. Respirations, pulse, blood pressure, pain and sedation ratings were assessed. Subjects rated their pain twice daily using a visual analog scale for 72 hr postoperatively. The subjects reported pain relief with both dosing regimens. No statistically significant differences between the groups were found in pain and sedation ratings, or length of time using the device, with the exception of a higher amount of MS used on postoperative day two by the infusion group (p less than 0.003). There seems to be a trend for the PCA + CI group to have less fluctuation in sedation between days and better pain control (as demonstrated by verbal and visual analog pain scores) on the third postoperative day. Statistical significance was not found, however. PCA plus continuous infusion of MS may be a beneficial approach to the management of postoperative pain in selected patients; studies to identify these patients need to be done.

Patients continue to suffer from pain despite their analgesic regimen and frequently from symptoms related to these interventions. This article describes the role that intrathecal analgesia may play in improving comfort for individuals experiencing refractory pain and/or symptoms of opioid therapy. Patient selection, staff education, institution requirements, medications, and titration guidelines also will be reviewed. Patients with cancer clearly deserve to achieve comfort; therefore, intrathecal therapy, which is a safe intervention, must be considered when refractory pain or symptoms occur.