Steven P. Stanos

Recommendations for the Pharmacological Management of Neuropathic Pain: An Overview and Literature Update

The Neuropathic Pain Special Interest Group of the International Association for the Study of Pain recently sponsored the development of evidence-based guidelines for the pharmacological treatment of neuropathic pain. Tricyclic antidepressants, dual reuptake inhibitors of serotonin and norepinephrine, calcium channel alpha(2)-delta ligands (ie, gabapentin and pregabalin), and topical lidocaine were recommended as first-line treatment options on the basis of the results of randomized clinical trials. Opioid analgesics and tramadol were recommended as second-line treatments that can be considered for first-line use in certain clinical circumstances. Results of several recent clinical trials have become available since the development of these guidelines. These studies have examined botulinum toxin, high-concentration capsaicin patch, lacosamide, selective serotonin reuptake inhibitors, and combination therapies in various neuropathic pain conditions. The increasing number of negative clinical trials of pharmacological treatments for neuropathic pain and ambiguities in the interpretation of these negative trials must also be considered in developing treatment guidelines. The objectives of the current article are to review the Neuropathic Pain Special Interest Group guidelines for the pharmacological management of neuropathic pain and to provide a brief overview of these recent studies.

Predicting total knee replacement pain: a prospective, observational study.

To describe the natural history of pain after total knee arthroplasty and to identify factors predicting excessive postoperative pain, we used a prospective, observational study assessing clinical and radiographic variables preoperatively and at 1, 3, 6, and 12 months after knee replacement. Data sources included the visual analog pain scale and other measures of patient health, psychologic state, and component reliability. Regression analyses were conducted to identify specific factors predictive of postoperative pain, controlling for inequality of variables, and confirmed using regression diagnostics. For 116 patients (149 knees; mean age, 66 years; 55.2% women), significant pain was reported by 72.3%, 44.4%, 22.6%, 18.4%, and 13.1%, respectively. No intergroup differences existed for anesthesia, weight, age, or gender. Patients with greater preoperative pain had more postoperative pain, used more home therapy, and postoperative manipulations. Preoperative depression and anxiety were associated with heightened pain at 1 year. Pain after knee replacement resolves quickly, declining to approximately 1/2 by 3 months. However, one in eight patients report moderate to severe pain 1 year after surgery despite an absence of clinical or radiographic abnormalities. Development of office-based preoperative screening tools and interventions for these patients may reduce postoperative costs and improve patient-perceived outcomes.

Interventional therapies, surgery, and interdisciplinary rehabilitation for low back pain: an evidence-based clinical practice guideline from the American Pain Society.

Study Design. Clinical practice guideline. Objective. To develop evidence-based recommendations on use of interventional diagnostic tests and therapies, surgeries, and interdisciplinary rehabilitation for low back pain of any duration, with or without leg pain. Summary of Background Data. Management of patients with persistent and disabling low back pain remains a clinical challenge. A number of interventional diagnostic tests and therapies and surgery are available and their use is increasing, but in some cases their utility remains uncertain or controversial. Interdisciplinary rehabilitation has also been proposed as a potentially effective noninvasive intervention for persistent and disabling low back pain. Methods. A multidisciplinary panel was convened by the American Pain Society. Its recommendations were based on a systematic review that focused on evidence from randomized controlled trials. Recommendations were graded using methods adapted from the US Preventive Services Task Force and the Grading of Recommendations, Assessment, Development, and Evaluation Working Group. Results. Investigators reviewed 3348 abstracts. A total of 161 randomized trials were deemed relevant to the recommendations in this guideline. The panel developed a total of 8 recommendations. Conclusion. Recommendations on use of interventional diagnostic tests and therapies, surgery, and interdisciplinary rehabilitation are presented. Due to important trade-offs between potential benefits, harms, costs, and burdens of alternative therapies, shared decision-making is an important component of a number of the recommendations.

Nonsurgical interventional therapies for low back pain: A review of the evidence for an American pain society clinical practice guideline

Study Design. Systematic review. Objective. To systematically assess benefits and harms of nonsurgical interventional therapies for low back and radicular pain. Summary of Background Data. Although use of certain interventional therapies is common or increasing, there is also uncertainty or controversy about their efficacy. Methods. Electronic database searches on Ovid MEDLINE and the Cochrane databases were conducted through July 2008 to identify randomized controlled trials and systematic reviews of local injections, botulinum toxin injection, prolotherapy, epidural steroid injection, facet joint injection, therapeutic medial branch block, sacroiliac joint injection, intradiscal steroid injection, chemonucleolysis, radiofrequency denervation, intradiscal electrothermal therapy, percutaneous intradiscal radiofrequency thermocoagulation, Coblation nucleoplasty, and spinal cord stimulation. All relevant studies were methodologically assessed by 2 independent reviewers using criteria developed by the Cochrane Back Review Group (for trials) and by Oxman (for systematic reviews). A qualitative synthesis of results was performed using methods adapted from the US Preventive Services Task Force. Results. For sciatica or prolapsed lumbar disc with radiculopathy, we found good evidence that chemonucleolysis is moderately superior to placebo injection but inferior to surgery, and fair evidence that epidural steroid injection is moderately effective for short-term (but not long-term) symptom relief. We found fair evidence that spinal cord stimulation is moderately effective for failed back surgery syndrome with persistent radiculopathy, though device-related complications are common. We found good or fair evidence that prolotherapy, facet joint injection, intradiscal steroid injection, and percutaneous intradiscal radiofrequency thermocoagulation are not effective. Insufficient evidence exists to reliably evaluate other interventional therapies. Conclusion. Few nonsurgical interventional therapies for low back pain have been shown to be effective in randomized, placebo-controlled trials.

Prospective examination of pain-related and psychological predictors of CRPS-like phenomena following total knee arthroplasty: a preliminary study

&NA; We hypothesized that preoperative emotional distress and pain intensity would predict the occurrence of signs and symptoms of complex regional pain syndrome (CRPS) following total knee arthroplasty (TKA). Depression (Beck Depression Inventory, BDI), anxiety (State Trait Anxiety Inventory, STAI), pain (McGill Pain Questionnaire–Short Form, MPQ), and signs/symptoms meeting IASP criteria for CRPS were assessed preoperatively, and at 1‐, 3‐, and 6‐months postoperatively in 77 patients undergoing TKA. The prevalence of subjects fulfilling CRPS criteria was 21.0% at 1 month, 13.0% at 3 months, and 12.7% at 6 months postoperative. Higher preoperative scores on the STAI predicted positive CRPS status at 1‐month follow‐up (P<0.05), with a similar non‐significant trend for preoperative BDI scores (P<0.10). Diagnostic sensitivity for the STAI was good (0.73), with moderate specificity (0.56). Neither measure predicted CRPS at later follow‐up (P>0.10). Greater preoperative pain intensity predicted positive CRPS status at 3‐month (MPQ‐Sensory and MPQ‐Affective; P<0.01) and 6‐month (MPQ‐Sensory) follow‐up (P<0.01), but not at 1‐month (P>0.10). Diagnostic sensitivity was high (0.83–1.00), with moderate specificity (0.53–0.60). Post‐TKA patients with CRPS were more depressed at 1‐month follow‐up (P<0.05) and more anxious at 6‐month follow‐up (P<0.05) than patients with ongoing non‐CRPS pain (all other comparisons non‐significant, P>0.10). Overall, results indicate that CRPS‐like phenomena occur in a significant number of patients early post‐TKA; however, it is not associated with significantly greater complaints of postoperative pain. There appears to be a modest utility for preoperative distress and pain in predicting CRPS signs and symptoms following TKA, although false positive rates are relatively high.

Assessment and Treatment of Psychosocial Comorbidities in Patients With Neuropathic Pain

Chronic neuropathic pain is a prevalent problem that eludes cure and adequate treatment. The persistence of intense and aversive symptoms, inadequacy of available treatments, and impact of such pain on all aspects of functioning underscore the important role of several psychosocial factors in causing, maintaining, and amplifying the perception of pain severity, coping adequacy, adaptation, impaired physical function, and emotional distress responses. Moreover, these factors have an influential role in response to treatment recommendations. In this article, we (1) review the prevalence and nature of emotional distress, (2) describe and propose methods for screening and comprehensive psychosocial assessment, and (3) review evidence supporting the potential complementary role of psychosocial treatments of patients with chronic pain. The cognitive-behavioral perspective and treatment approach are emphasized because the greatest amount of evidence supports their benefits. Published results of psychological treatments are modest; however, the same indictment can be placed on currently available pharmacological, medical, and interventional treatments for patients with chronic pain. We note the limited research on the effectiveness of psychological treatment specifically applied to patients with chronic neuropathic pain but suggest that it is reasonable to extrapolate from successful trials in other types of chronic pain. Furthermore, psychological approaches should not be viewed as alternatives but rather should be integrated as part of a comprehensive approach to the treatment of patients with chronic neuropathic pain.

Focused Review of Interdisciplinary Pain Rehabilitation Programs for Chronic Pain Management

Interdisciplinary pain rehabilitation programs (IPRPs) are based on a functional restoration approach to treating complex chronic pain conditions. With a greater appreciation for a biopsychosocial approach to more effectively manage patients with chronic pain has come the development of more comprehensive treatment programs with less of a biomedical emphasis (i.e., interventional therapy, unimodal physical therapy, and passive modalities) and more of a biopsychosocial one. Interdisciplinary programs involve the use of multiple disciplines such as physical and occupational therapy, pain psychology, medical pain management, vocational rehabilitation, relaxation training, and nursing educations. Multiple psychometric tools are used in the assessment process and along treatment to better assess outcomes. This article will examine components of IPRPs, discuss desirable features of successful programs and teams, and more closely review four established outpatient pain programs in the United States. A greater understanding of the unique features and shared values of successful programs will help one better understand how these programs can be more widely used and available. The review will also highlight common psychometric outcomes tools used in assessing patients and monitoring outcomes. Most importantly, the review will help to answer a common question, even among pain physicians: “What goes on in those chronic pain programs?”

Consensus Recommendations on Initiating Prescription Therapies for Opioid-Induced Constipation

Abstract Objective Aims of this consensus panel were to determine (1) an optimal symptom‐based method for assessing opioid‐induced constipation in clinical practice and (2) a threshold of symptom severity to prompt consideration of prescription therapy. Methods A multidisciplinary panel of 10 experts with extensive knowledge/experience with opioid‐associated adverse events convened to discuss the literature on assessment methods used for opioid‐induced constipation and reach consensus on each objective using the nominal group technique. Results Five validated assessment tools were evaluated: the Patient Assessment of Constipation–Symptoms (PAC‐SYM), Patient Assessment of Constipation–Quality of Life (PAC‐QOL), Stool Symptom Screener (SSS), Bowel Function Index (BFI), and Bowel Function Diary (BF‐Diary). The 3‐item BFI and 4‐item SSS, both clinician administered, are the shortest tools. In published trials, the BFI and 12‐item PAC‐SYM are most commonly used. The 11‐item BF‐Diary is highly relevant in opioid‐induced constipation and was developed and validated in accordance with US Food and Drug Administration guidelines. However, the panel believes that the complex scoring for this tool and the SSS, PAC‐SYM, and 28‐item PAC‐QOL may be unfeasible for clinical practice. The BFI is psychometrically validated and responsive to changes in symptom severity; scores range from 0 to 100, with higher scores indicating greater severity and scores >28.8 points indicating constipation. Conclusions The BFI is a simple assessment tool with a validated threshold of clinically significant constipation. Prescription treatments for opioid‐induced constipation should be considered for patients who have a BFI score of ≥30 points and an inadequate response to first‐line interventions.

Medication Quantification Scale Version III: internal validation of detriment weights using a chronic pain population.

Introduction:  We report an internal validation of the Medication Quantification Scale (MQS III) using a chronic pain population. The MQS was designed as a methodology of quantifying different drug regimens in 1992, updated in 1998 (MQS II), and again updated in 2003 (MQS III) using “detriment” weights determined by surveying physician members of the American Pain Society. The MQS has been used as a unitary clinical and research outcome.

Topical Therapies in the Management of Chronic Pain

Abstract Chronic pain, whether localized or generalized, is a widespread, often debilitating condition affecting > 25% of adults in the United States. Oral agents are the cornerstone of chronic pain treatment, but their use may be limited in certain patients, particularly the elderly. Topical therapies offer advantages over systemically administered medications, including the requirement of a lower total systemic daily dose for patients to achieve pain relief, site-specific drug delivery, and avoidance of first-pass metabolism, major drug interactions, infections, and systemic side effects. Several types of topical agents have been shown to be useful in the treatment of patients with chronic pain. Both capsaicin and topical diclofenac have been shown to be effective in the treatment of patients with chronic soft-tissue pain. In patients with hand and knee osteoarthritis (OA), the American College of Rheumatology generally recommends oral treatments (acetaminophen, oral nonsteroidal anti-inflammatory drugs [NSAIDs], tramadol, and intra-articular corticosteroids) and topical NSAIDs equally, favoring topical agents only for patients who have pre-existing gastrointestinal risk or are aged > 75 years. Topical NSAIDs have been shown to provide relief superior to that of placebo and comparable to that of oral ibuprofen. Similarly, ketoprofen gel has been shown to be superior to placebo and similar to oral celecoxib in reducing pain in patients with knee OA. Different formulations of topical diclofenac (including the diclofenac hydroxyethyl pyrrolidine patch, diclofenac sodium gel, and diclofenac sodium topical solution 1.5% w/w with dimethyl sulfoxide USP) have been shown to be superior to placebo and comparable to oral diclofenac in the treatment of patients with pain due to knee OA, with a lower incidence of gastrointestinal complaints than with the oral formulation. In patients with neuropathic pain, topical forms of both capsaicin and lidocaine have been shown to be useful in the treatment of postherpetic neuralgia and diabetic peripheral neuropathic pain. Lidocaine has also demonstrated efficacy in relieving patient pain due to complex regional pain syndrome and may be useful in the treatment of patients with neuropathic pain who have cancer, although clinical trial results have not been consistent. Data suggest that topical therapies may offer a safe, well-tolerated, and effective alternative to systemic therapies in the treatment of patients with chronic, localized musculoskeletal and neuropathic pain.