Chronic Pain: Pharmacologic Management

Educational Objectives

The goal of this program is to improve management of common pain syndromes. After hearing and assimilating this program, the clinician will be better able to:

1. Assess evidence about use of opioids in chronic musculoskeletal conditions.

2. Select appropriate therapy for chronic neuropathic pain.

Summary

Opioids: meta-analysis shows benefit of use of opioids for 1 to 9 wk in patients with chronic low back pain; observational studies show benefit for ≤3 mo with many side effects; survey found 40% agree or strongly agree that opioids should be used for chronic musculoskeletal pain (nearly 20% disagree or strongly disagree)

Rheumatoid arthritis (RA): Cochrane review showed no evidence to support use of weak opioids (eg, tramadol [eg, Rybix, Ryzolt, Ultram]) beyond use for acute flares, and no evidence to support use of strong opioids to improve pain or function; recent meta-analysis showed high (27%-28%) opioid dropout rate in studies in osteoarthritis due to side effects

Stable vs escalating doses: study saw small difference in pain scores reported by selected patients (ie, with no history of substance use) who received stable doses (doses controlled by physician), compared to those in patients allowed to escalate dose (ie, doses increased by patient, then maintained); 27% of patients removed from study due to misuse and noncompliance (despite careful selection)

Anticonvulsants: effective for neuropathic pain extending to 18 wk; pregabalin (Lyrica) approved for neuropathic pain in spinal cord injury, pain due to diabetic neuropathy, and postherpetic neuralgia; improvement in VAS score, 2 (0 for placebo); 40% of patients have ≥50% improvement in pain

Antidepressants: use of tricyclic antidepressants in variety of chronic pain states (including neuropathic pain) has level I evidence; use of selective serotonin-norepinephrine reuptake inhibitors (SSNRIs; eg, duloxetine [Cymbalta], venlafaxine) in treatment of neuropathic pain has level I evidence, but not for pain due to diabetic neuropathy

Benzodiazepines: have poor evidence for use in chronic musculoskeletal pain disorders; addictive; rapid withdrawal can result in seizures, catatonia, coma, and respiratory death; not recommended

Dextromethorphan and memantine: evidence for effectiveness very limited; level I studies show lack of effectiveness in postherpetic neuralgia, pain due to diabetic neuropathy, complex regional pain syndrome, and phantom limb pain

Topical agents: evidence for use in neuropathic pain limited; lack of effectiveness of some agents in postherpetic neuralgia and diabetic neuropathy established with level I evidence; study — looked at nearly 300 patients with postherpetic neuralgia; change in VAS score in patients who received topical cream (amitriptyline plus ketamine) and oral placebo, 2.4 (2.5 in patients who received oral gabapentin [600 mg 3 times/day] and topical placebo; 1.9 in patients who received oral placebo and topical placebo; statistically significant)

Long-term opiates: found to be ineffective in study looking at functional outcomes (eg, distance patients can ambulate, time required to walk 12 ft, decrease in amount of opiates used) in patients with chronic musculoskeletal pain, RA, and osteoarthritis; controlled trial found acetaminophen to be associated with better outcomes than tramadol; conclusions — opioids not highly beneficial for chronic musculoskeletal pain; recommended by American Society of Anesthesiology and other groups as appropriate treatment or intervention; problems — opioid-related deaths in United States; study looking at admissions to pain clinic in patients with musculoskeletal pain unrelated to cancer found patients on low opioid doses had mean daily morphine equivalent of 200 mg/day (patients with psychosocial risk factors had mean dose of 400 mg/day); significant morbidity with respect to respiratory function associated with doses of 100 mg/day

Management: explain lack of evidence on long-term opioid use to patient; consider short-term use of short-acting opiates for acute flares; opiates ineffective in patients with evidence of centralized pain disorder (eg, fibromyalgia; use centrally acting agents, eg, SSNRIs, serotonin reuptake inhibitors, gabapentin, pregabalin); exercise — changes neurochemistry to improve function; bundle with CBT; explain that risk factors warrant need for multidisciplinary approach, and that physical therapy alone ineffective

Readings

Argoff CE et al: Treatment of postherpetic neuralgia: a review of therapeutic options. J Pain Symptom Manage. 2004 Oct;28(4):396-411; Bergman S: Management of musculoskeletal pain. Best Pract Res Clin Rheumatol. 2007 Feb;21(1):153-66; Bonezzi C, Demartini L: Treatment options in postherpetic neuralgia. Acta Neurol Scand Suppl. 1999;173:25-35; Brunner E et al: Can cognitive behavioural therapy based strategies be integrated into physiotherapy for the prevention of chronic low back pain? A systematic review. Disabil Rehabil. 2012 May 21 [Epub ahead of print]; Clauw D, McCarberg BH: Managing chronic pain with nonopioid analgesics: a multidisciplinary consult. Am J Med. 2012 May;125(5):S1; Devkota P et al: Posterior lumbar interbody fusion for the management of spondylolisthesis. Nepal Med Coll J. 2011 Mar;13(1):46-9; Donelson R et al: Influence of Directional Preference on Two Clinical Dichotomies: Acute Versus Chronic Pain and Axial Low Back Pain Versus Sciatica. PM R. 2012 Jun 22 [Epub ahead of print]; Mao J et al: Combination drug therapy for chronic pain: a call for more clinical studies. J Pain. 2011 Feb;12(2):157-66; Mehling WE et al: The prognosis of acute low back pain in primary care in the United States: a 2-year prospective cohort study. Spine (Phila Pa 1976). 2012 Apr 15;37(8):678-84; Morita T et al: Lumbar spondylolysis in children and adolescents. J Bone Joint Surg Br. 1995 Jul;77(4):620-5; Naliboff BD et al: A randomized trial of 2 prescription strategies for opioid treatment of chronic nonmalignant pain. J Pain. 2011 Feb;12(2):288-96; Nicholson JA: What are the standards of care for cauda equina syndrome? Br J Neurosurg. 2012 May 23 [Epub ahead of print]; Park HJ, Moon DE: Pharmacologic management of chronic pain. Korean J Pain. 2010 Jun;23(2):99-108; Rundell SD, Davenport TE: Patient education based on principles of cognitive behavioral therapy for a patient with persistent low back pain: a case report. J Orthop Sports Phys Ther. 2010 Aug;40(8):494-501; Sairyo K et al: Painful lumbar spondylolysis among pediatric sports players: a pilot MRI study. Arch Orthop Trauma Surg. 2011 Nov;131(11):1485-9; Sairyo K et al: Development of spondylolytic olisthesis in adolescents. Spine J. 2001 May-Jun;1(3):171-5; Sindrup SH et al: Antidepressants in the treatment of neuropathic pain. Basic Clin Pharmacol Toxicol. 2005 Jun;96(6):399-409; Watson CP et al: Nontricyclic antidepressant analgesics and pain: are serotonin norepinephrine reuptake inhibitors (SNRIs) any better? Pain. 2011 Oct;152(10):2206-10; White AP et al: Pharmacologic management of chronic low back pain: synthesis of the evidence. Spine (Phila Pa 1976). 2011 Oct 1;36(21 Suppl):S131-43.

Disclosures

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the planning committee to disclose relevant financial relationships within the past 12 months that might create any personal conflicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, Dr. Chiodo and the planning committee reported nothing to disclose.

Acknowledgements

Dr. Chiodo was recorded in Bellaire, MI, at 48th Annual Northern Michigan Summer Conference, presented June 18-22, 2012, by University of Michigan Medical School, Department of Family Medicine. For a calendar of upcoming courses from this sponsor, please visit http://cme.med.umich.edu/events/. The Audio-Digest Foundation thanks Dr. Chiodo and the University of Michigan Medical School, Department of Family Medicine, for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

FP603502

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.

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