I was asked in a private message concerning the use of "peridural morphine" for the treatment of a person with neuropathic pain after spinal cord injury. Here is what I could find. Peridural and epidural are the same things. The drug is applied to the outside of the dura surrounding the spinal cord. Almost all the studies that I could find were related to acute postoperative pain and not neuropathic pain. Many of the studies used bupivacaine rather than morphine. There are significant side effects and only short term treatments were given to avoid complications. My conclusion is that this epidural morphine and other analgesics are suitable for postoperative pain management but not for chronic pain management.

Chia, et al. (2006) compared thoracic epidural neostigmine and bupivacaine plus morphine epidural infusion after thoracic surgery, suggesting that both are effective.

Viscusi (2005) suggest that epidural infusions of analgesics is associated with side effects such as lowered blood pressure. He pointed out a new treatment option of a single epidural injection of morphine to avoid these complications.

Shapiro, et al. (2005) assessed 1524 postoperative patients and found that morphine respiratory depression is common.

Dernedde, et al. (2005) used levobupivacaine and found that this was effective.

Weinbroum (2005) compared intravenous and epidural analgesic treatments, finding that epidural ropivacaine and fentanyl reduces oncologic pain better than intravenous morphine.

Yukawa, et al. compared continuous subcutaneous morphine (SCM), continuous epidural morphine (CEM), and diclofencac sodium (DS). This is a randomized clinical trial. They showed no significant difference between the three groups, that DS provided more rapid onset of pain relief but required more supplemental analgesic drugs (suggesting that it is not as effective). Both CEM and DS had high rates of minor complications.

Aurilio, et al. (2005) applied transdermal buprenorphine (a powerful opioid) and peridural infusion of morphine and naropine to the spinal cord, to treat patients with ischemic pain. The treatment appears to increase the number of hours that the patients can sleep. The goal was to block the various kinds of opiate receptors.

Phillips & Currier (2004) recently reviewed the subject of analgesic pharmacology, pointing out that combination therapies are more effective than single therapies and listing many agents that are non-opioid in their mechanism of action.

Barzoi, et al. (2000) compared epidural morphine plus bupivacaine and epidural morphine alone in 60 patients (30 patients per group) after abdomenal surgery. They found that morphine plus bupivacaine was more effective than morphine alone in allowing rapid return of bowel movement and earlier ability to eat.

References Cited
  1. Chia YY, Chang TH, Liu K, Chang HC, Ko NH and Wang YM (2006). The efficacy of thoracic epidural neostigmine infusion after thoracotomy. Anesth Analg 102: 201-8. Few anesthesia studies have explored perioperative continuous epidural infusion of neostigmine. We examined such a regimen in thoracotomy patients. Ninety patients were randomized to one of three groups in this double-blind trial. Before anesthesia induction, an epidural catheter was inserted in all patients at T5-8 levels under local anesthesia. Pre-neo patients received bolus 500-microg epidural neostigmine before anesthesia induction followed by infusion of 125 microg/h until the end of surgery. Post-neo patients received epidural saline during the same time periods plus bolus 500-microg epidural neostigmine at end of surgery. Patients in the control group received saline placebo during all three periods. Patients in the neostigmine groups postoperatively received patient-controlled epidural analgesia with morphine 0.02 mg/mL, bupivacaine 0.08 mg/mL, and neostigmine 7 microg/mL. Control patient-controlled epidural analgesia excluded neostigmine. Data were recorded for 6 postoperative days. Daily patient-controlled epidural analgesia consumption (mL) for Pre-neo patients was significantly less than that of post-neo and control group patients for postoperative days 1-6 (at least 10% and 16% less, respectively; P < 0.05). There was a modest decrease in pain intensity on postoperative days 3-6 for pre-neo patients versus other groups (P < 0.05). These results suggest that continuous thoracic epidural neostigmine started before anesthesia provided preemptive, preventive analgesia and an analgesic-sparing effect that improved postoperative analgesia for these patients without increasing the incidence of adverse effects. Department of Anesthesiology, Kaohsiung Veterans General Hospital and School of Medicine, National Yang-Ming University, Taiwan. http://www.ncbi.nlm.nih.gov/entrez/q..._uids=16368830
  2. Viscusi ER (2005). Emerging techniques in the management of acute pain: epidural analgesia. Anesth Analg 101: S23-9. Epidural analgesia, often using opioids intraoperatively and postoperatively, is widely accepted as a valuable modality for perioperative pain management. In this review I present data from meta-analyses and recently published trials that evaluate the perioperative use of opioids administered epidurally or parenterally (as-needed or by patient-controlled analgesia) and their effect on outcome. Published effects of perioperative epidural techniques on cardiac and pulmonary function are reviewed. Clinical and practical issues associated with epidural anesthesia and analgesia include the existence of analgesic gaps (often related to technical difficulties with the pump or use of an indwelling catheter), the occurrence of hypotension, and compatibility with anticoagulation therapy. A new treatment option, a single epidural injection of morphine for continuous perioperative analgesia (DepoDur; Endo Pharmaceuticals Inc, Chadds Ford, PA), may reduce some of these problems. Data from recent clinical studies are presented. Department of Anesthesiology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107-5092, USA. eugene.viscusi@jefferson.edu http://www.ncbi.nlm.nih.gov/entrez/q..._uids=16334490
  3. Shapiro A, Zohar E, Zaslansky R, Hoppenstein D, Shabat S and Fredman B (2005). The frequency and timing of respiratory depression in 1524 postoperative patients treated with systemic or neuraxial morphine. J Clin Anesth 17: 537-42. STUDY OBJECTIVE: To describe the frequency and timing of intravenous patient-controlled analgesia (IV-PCA) or neuraxial morphine-induced postoperative respiratory depression. DESIGN: Audit of data captured by routine quality assurance of the acute pain protocols that were implemented by nurses performing routine postoperative care. SETTING: The surgical wards of a university-affiliated, 700-bed, tertiary hospital. PATIENTS AND INTERVENTIONS: In real time, the data of all patients enrolled into our Acute Pain Service (APS) were entered and stored in the APS database. Thereafter, patients who had received IV morphine via a PCA device or neuraxial morphine between January 1999 and December 2002 were isolated. From this subset, all patients in whom a respiratory rate (RR) less than 10 breaths per minute was recorded were retrieved. MEASUREMENTS AND MAIN RESULTS: From a total of 4500 patients, IV or neuraxial morphine was administered to 1524 patients. Eighteen (1.2%) cases of an RR less than 10 breaths per minute were recorded (13 patients, 4 patients, and 1 patient in the IV-PCA, daily epidural morphine, and single-dose intrathecal morphine groups, respectively). A direct correlation between intraoperative fentanyl administration and postoperative respiratory depression was demonstrated between the IV-PCA (P = 0.03) and epidural groups (P = 0.05). The time from IV-PCA initiation or last neuraxial morphine administration until the diagnosis of respiratory depression ranged between 2 hours and 31.26 hours and 2 hours and 12.15 hours, respectively. Ten (55.6%) patients received naloxone. CONCLUSION: Morphine-induced respiratory depression may occur at any time during the APS admission. However, the optimal frequency of intermittent RR monitoring is unknown. Furthermore, because multiple variables (age, sex, prior opioid administration, site of operation) may affect morphine-induced respiratory depression, further investigation must be performed to determine the ideal monitoring protocol. Department of Anesthesiology, Critical Care and Pain Management, Meir Hospital, Kfar Saba 44281, Israel. http://www.ncbi.nlm.nih.gov/entrez/q..._uids=16297754
  4. Dernedde M, Stadler M, Bardiau F and Boogaerts JG (2005). Comparison of 2 concentrations of levobupivacaine in postoperative patient-controlled epidural analgesia. J Clin Anesth 17: 531-6. STUDY OBJECTIVES: To evaluate the quality of analgesia and the incidence of side effects of 2 different concentrations of levobupivacaine given as an equal milligram-bolus dose (5 mg) via patient-controlled epidural analgesia after abdominal surgery. DESIGN: Prospective, randomized, blinded study. SETTING: Postanesthesia care unit and surgical wards of a university hospital. PATIENTS: Forty-nine patients (41 with complete file) undergoing major lower abdominal surgery. INTERVENTIONS: The patients were randomly assigned to 2 groups: 1.5 mg/mL (bolus 3.3 mL, lockout 20 minutes, n = 26) and 5 mg/mL (bolus 1 mL, lockout 20 minutes, n = 23). The epidural catheter was inserted in the low thoracic level (T9-T12) before induction of a standardized general anesthesia technique. MEASUREMENTS: Demography, upper sensory block, visual analog scale scores at rest and after coughing, levobupivacaine and rescue morphine consumption, motor blockade, hemodynamics, postoperative nausea and vomiting, sedation, and patient satisfaction were recorded within the first 48 hours. MAIN RESULTS: Both groups were similar with regard to demographics, upper level of sensory blockade (T8), and visual analog scale pain scores at rest and after coughing, as well as levobupivacaine and subcutaneous rescue morphine consumption. Motor blockade in the lower limbs was very low in both groups. Arterial blood pressure was slightly lower in the 5 mg/mL group during the first 24 hours (P = 0.052). Five patients in the 1.5 mg/mL and 7 in the 5 mg/mL group had postoperative nausea and vomiting (P = 0.43). No other side effects were recorded, and all of the patients were satisfied. CONCLUSIONS: Administering the same dose of levobupivacaine in either a low or high concentration via patient-controlled epidural analgesia mode provides an equal quality of analgesia with no difference in the incidence of side effects. Department of Anesthesiology, University Hospital Center, 6000 Charleroi, Belgium. mira.dernedde@chu-charleroi.be http://www.ncbi.nlm.nih.gov/entrez/q..._uids=16297753
  5. Weinbroum AA (2005). Superiority of postoperative epidural over intravenous patient-controlled analgesia in orthopedic oncologic patients. Surgery 138: 869-76. BACKGROUND: Surgery for bone malignancy is associated with intense postoperative pain. Patient-controlled epidural analgesia (PCEA) and intravenous patient-controlled analgesia (IV-PCA) are used currently for postoperative pain control. METHODS: The degree of pain control after resection of bone malignancy under combined general and epidural anesthesia followed postoperatively by prospectively randomized PCEA (ropivacaine 3.2 mg + fentanyl 8 microg/dose) or IV-PCA (morphine 2 mg/dose) (n = 35/group) was assessed. Postoperative analgesia delivery continued for up to 96 h; intramuscular rescue with diclofenac 75 mg was also available. RESULTS: The mean hourly pain score among the PCEA patients was 3.0 +/- 0.9, compared with 4. 7 +/- 0.6 (P < .01) among the IV-PCA patients. All mean hourly pain scores in the PCEA patients, except for the first 2 hours of treatment, were less than 4/10, but they were higher in the IV-PCA patients. The demand for diclofenac was 2 times (n = 10) lower for the PCEA patients, compared with their IV counterparts (n = 20, P < .01); the same difference applied to the overall side effects (n = 15 vs n = 30, P < .01). Self-rated wakefulness and feelings of well-being were better in the PCEA patients. CONCLUSIONS: Postoperative ropivacaine + fentanyl via PCEA reduces pain better and affords better subjective feelings than IV morphine via PCA after resection of bone malignancy carried out under combined general and epidural anesthesia. Post-Anesthesia Care Unit, Tel Aviv Sourasky Medical Center and the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. draviw@tasmc.health.gov.il http://www.ncbi.nlm.nih.gov/entrez/q..._uids=16291387
  6. Yukawa Y, Kato F, Ito K, Terashima T and Horie Y (2005). A prospective randomized study of preemptive analgesia for postoperative pain in the patients undergoing posterior lumbar interbody fusion: continuous subcutaneous morphine, continuous epidural morphine, and diclofenac sodium. Spine 30: 2357-61. STUDY DESIGN: A prospective randomized clinical trial in preemptive analgesia for postoperative pain was conducted. OBJECTIVE: To compare the efficacy of three preemptive analgesics combined with local anesthesia: continuous subcutaneous morphine (SC), continuous epidural morphine (ED), and diclofenac sodium (DS). SUMMARY OF BACKGROUND DATA: Systemic opioids are known to be effective methods of postoperative pain control. The use of epidural morphine for postoperative analgesia has been a standard treatment in spinal surgery. Only a few studies in the literature have investigated the efficacy of preemptive analgesia using morphine. This is the first prospective randomized clinical trial to assess both subcutaneous and epidural continuous administration of opioids for preemptive analgesia. METHODS: For this study, 73 patients were assigned randomly to one of three treatment groups: SC, ED, or DS. All patients underwent posterior lumbar interbody fusion with instrumentation. Pain management was assessed using the visual analogue scale (VAS). Usage of supplemental analgesics, the time to first request of them, and side effects were also investigated. RESULTS: Twenty-two patients were randomized to SC, 23 to ED, and 27 to DS. No baseline variable differences among the three groups were seen. The results showed no significant difference in analgesic effects among those three preemptive analgesics. Only immediately after surgery (at 0 hours), the VAS of the DS group was lowest among three groups. But the DS group took more supplemental analgesic drugs until 72 hours, and the time to first request of this group was shorter than that of the other two groups. High rates of minor side effects were seen in both the ED and DS groups. SC gave moderate analgesic effects as well as the other two groups with few adverse effects. CONCLUSIONS: DS provided a favorable effect immediately after surgery, but the effective time was short and the patient needed more supplemental drugs after that. ED did not give the expected effect, with comparatively high rates of side effects. Continuous epidural anesthesia did not seem to be suitable for preemptive analgesia. Continuous subcutaneous morphine brought some analgesic effects with a low rate of complications. It can be an attractive method for postoperative analgesia with technical ease. Department of Orthopedic Surgery, Chubu Rosai Hospital, Nagoya, Japan. yukawa.ort@chubuh.rofuku.go.jp http://www.ncbi.nlm.nih.gov/entrez/q..._uids=16261108
  7. Aurilio B, Pace MC and Passavanti MB (2005). Transdermal buprenorphine combined with spinal morphine and naropine for pain relief in chronic peripheral vasculopathy. Minerva Anestesiol 71: 445-9. The AIM: of this study was to evaluate the effectiveness and the safety of the association of buprenorphine transdermal delivery system (TDS) (Transtec TDS) and peridural infusion of morphine and naropine, for the control of ischemic pain in patients suffering from peripheral arteriopathy. The administration of an opioid, pure agonist, as morphine, with a partial agonist opioid, as the buprenorphine, was used. Buprenorphine has shown a higher liposolubility in supraspinal districts, while the morphine acts above all on the mu receptor subtype of the spinal cord. In this way it's possible a contemporary activation of spinal and supraspinal antinociceptive mechanisms. Furthermore, the incidence of side effects is reduced by buprenorphine, which antagonizes the central effect of morphine. In this study, 43 patients were recruited, suffering from chronic pain in Fontaine stage III-IV obstructive arteriopathy, scheduled for surgery. The patients have been divided into 2 equal groups for age, sex, pathology and intensity of pain. In the first group (TTDS), at first session, a buprenorphine patch 35 mug/h (Transtec TDS) has been applied, and after 24h, a peridural catheter with elastomeric system was positioned; 100 mL (2 mg/mL) of naropine and 2 mg of morphine, 4 mL/h in 24 h, were administered. In the second group (naropine morphine, NM), buprenorphine patch was not applied and analgesia was obtained only by using peridural catheter with elastomeric system at the same doses administered in the first group. At the daily control patients with visual analogical scale (VAS) =/>40 mm received an additional dose of morphine from 2 mg to 6+/-2 mg. VAS (0-100 mm) and the evaluation of the number of the hours of sleep were used to evaluate the analgesic effectiveness of the treatment. Side effects, opioid tolerance and abuse were always recorded. All parameters were evaluated daily for a period of 20+/-5 days. The results indicate that in group TTDS there was an improvement of pain symptomatology, also confirmed by the increased hours of sleep and the lower incidence of side effects. Instead in group NM, pain control was less effective, 18 patients needed a rescue dose of morphine, and the incidence of side effects increased. Department of Anesthesia, Surgical Sciences and Emergencies, Second University of Naples, Naples, Italy. http://www.ncbi.nlm.nih.gov/entrez/q..._uids=16012418
  8. Phillips WJ and Currier BL (2004). Analgesic pharmacology: II. Specific analgesics. J Am Acad Orthop Surg 12: 221-33. Methods of treatment are different for acute and chronic pain. For acute pain, analgesics such as nonsteroidal anti-inflammatory drugs and opiates are commonly used, sometimes combined with regional anesthesia, such as peripheral nerve block or peridural local anesthesia. The mechanism of transition from an acute to a chronic pain state is poorly understood. Only NMDA receptor antagonists and epidural morphine have shown relatively consistent results as preemptive analgesics. Agents more successfully used to manage chronic pain include those that modify the neurochemistry of the spinal cord dorsal horn, such as tricyclic antidepressants, anticonvulsants, gamma-amino butyric acid agonists, local anesthetic analogs, and NMDA antagonists. Opiates may be used chronically, but tolerance and lack of efficacy may then develop. In selected patients with refractory chronic pain, centrally administered analgesics may be considered, including opiates, dilute local anesthetic, NMDA receptor antagonists, clonidine, midazolam, baclofen, or calcium channel blockers. For both acute and chronic pain, a single agent may be less effective than combinations of analgesics with different mechanisms of action. Anesthesia and Emergency Medicine, Department of Emergency Medicine and Anesthesiology, University of Mississippi, Jackson, MS, USA. http://www.ncbi.nlm.nih.gov/entrez/q..._uids=15473674
  9. Barzoi G, Carluccio S, Bianchi B, Vassia S, Colucci G and Mangiante GL (2000). Morphine plus bupivacaine vs. morphine peridural analgesia in abdominal surgery: the effects on postoperative course in major hepatobiliary surgery. HPB Surg 11: 393-9. Anaesthesia and surgical procedures lead to a reduction of intestinal motility, and opioids may produce a postoperative ileus, that might delay postoperative feeding. The aim of this prospective randomised study is to test whether or not different kinds of epidural analgesia (Group A: morphine 0.0017 mg/kg/h and bupivacaine 0.125%-0.058 mg/kg/h; Group B: morphine alone 0.035 mg/kg/12h in the postoperative period) allow earlier postoperative enteral feeding, enhance intestinal motility a passage of flatus and help avoid complications, such as nausea, vomiting, ileus, diarrhoea, pneumonia or other infective diseases. We included in the study 60 patients (28 males and 32 females) with a mean age of 61.2 years (range 50-70) and with an ASA score of 2 or 3. All patients had hepato-biliary-pancreatic neoplasm and were candidates for major surgery. We compared two different pharmacological approaches, i.e., morphine plus bupivacaine (30 patients, Group A) versus morphine alone (30 patients, Group B). Each medication was administered by means of a thoracic epidural catheter for the control of postoperative pain. In the postoperative course we recorded every 6 hours peristaltic activity. We also noted morbidity (pneumonia, wound sepsis) and mortality. Effective peristalsis was present in all patients in Group A within the first six postoperative hours; in Group B, after 30 hours. Six patients in Group A had bowel motions in the first postoperative day, 11 in the second day, 10 in the third day and 3 in fourth day, while in Group B none in the first day, two in the second, 7 in the third, 15 in the fourth, and 6 in the fifth: the difference between the two groups was significant (p<0.05 in 1st, 2nd, 4th and 5th days). Pneumonia occurred in 2 patients of Group A, and in 10 of Group B (p < 0.05). We conclude that epidural analgesia with morphine plus bupivacaine allowed a move rapid return to normal gut activity and early enteral nutrition compared with epidural analgesia with morphine alone. Institute of Anesthesiology and Intensive Care, University of Verona, Italy. http://www.ncbi.nlm.nih.gov/entrez/q..._uids=10977118