A randomized, double-blind, double-dummy comparison of short- and long-acting dihydrocodeine in chronic non-malignant pain

The Use of Opioids in the Management of Chronic Pain: Synopsis of the 2022 Updated U.S. Department of Veterans Affairs and U.S. Department of Defense Clinical Practice Guideline

DESCRIPTION

In May 2022, leadership within the U.S. Department of Veterans Affairs (VA) and U.S. Department of Defense (DoD) approved a joint clinical practice guideline for the use of opioids when managing chronic pain. This synopsis summarizes the recommendations that the authors believe are the most important to highlight.

METHODS

In December 2020, the VA/DoD Evidence-Based Practice Work Group assembled a team to update the 2017 VA/DoD Clinical Practice Guideline for Opioid Therapy for Chronic Pain. The guideline development team included clinical stakeholders and conformed to the National Academy of Medicine's tenets for trustworthy clinical practice guidelines. The guideline team developed key questions to guide a systematic evidence review that was done by an independent third party and distilled 20 recommendations for care using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. The guideline team also created 3 one-page algorithms to help guide clinical decision making. This synopsis presents the recommendations and highlights selected recommendations on the basis of clinical relevance.

RECOMMENDATIONS

This guideline is intended for clinicians who may be considering opioid therapy to manage patients with chronic pain. This synopsis reviews updated recommendations for the initiation and continuation of opioid therapy; dose, duration, and taper of opioids; screening, assessment, and evaluation; and risk mitigation. New additions are highlighted, including recommendations about the use of buprenorphine instead of full agonist opioids; assessing for behavioral health conditions and factors associated with higher risk for harm, such as pain catastrophizing; and the use of pain and opioid education to reduce the risk for prolonged opioid use for postsurgical pain.

Effect of an opioid management program for Colorado workers' compensation providers on adherence to treatment guidelines for chronic pain

OBJECTIVE

The aim of this study was to examine adherence of state guidelines for Colorado workers' compensation physicians/providers treating individuals as injured workers with chronic pain after initiation of an opioid management program and provider incentives.

METHODS

A retrospective cohort of chronic, non-cancer pain claims was constructed from the Colorado's workers' compensation database. Adherence to treatment guidelines and opioid prescribing practices were evaluated during implementation of a new billing code to incentivize adherence.

RESULTS

Overall, less than 33% of claims showed evidence of opioid management. Comprehensive opioid management was observed in only 4.4% of claims. In 2010, after implementing the new billing code, the ratio of long acting opioids to short acting opioids decreased from 0.2 to 0.13; returning to 0.2 in one year. Similarly, morphine equivalent doses declined for a short period.

CONCLUSIONS

Incentivizing physicians to adhere to chronic pain management guidelines only temporarily improves prescribing practices.

Drug therapy for chronic idiopathic axonal polyneuropathy

BACKGROUND

Chronic idiopathic axonal polyneuropathy (CIAP) is an insidiously progressive sensory or sensorimotor polyneuropathy that affects elderly people. Although severe disability or handicap does not occur, CIAP reduces quality of life. CIAP is diagnosed in 10% to 25% of people referred for evaluation of polyneuropathy. There is a need to gather and review emerging evidence on treatments, as the number of people affected is likely to increase in ageing populations. This is an update of a review first published in 2004 and previously updated in 2006, 2008, 2011 and 2013.

OBJECTIVES

To assess the effects of drug therapy for chronic idiopathic axonal polyneuropathy for reducing disability and ameliorating neurological symptoms and associated impairments, and to assess any adverse effects of treatment.

SEARCH METHODS

In July 2016, we searched Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews in the Cochrane Library, MEDLINE, Embase, and the Web of Science. We searched two trials registries for ongoing trials. We also handsearched the reference lists of relevant articles, reviews and textbooks identified electronically, and we would have contacted authors and other experts in the field to identify additional studies if this seemed useful.

SELECTION CRITERIA

We sought all randomised or quasi-randomised (alternate or other systematic treatment allocation) trials that examined the effects of any drug therapy in people with CIAP at least one year after the onset of treatment. People with CIAP had to fulfil the following criteria: age 40 years or older, distal sensory or sensorimotor polyneuropathy, absence of systemic or other neurological disease, chronic clinical course not reaching a nadir in less than two months, exclusion of any recognised cause of the polyneuropathy by medical history taking, clinical or laboratory investigations, and electrophysiological studies in agreement with axonal polyneuropathy, without evidence of demyelinating features. The primary outcome was the proportion of participants with a significant improvement in disability. Secondary outcomes were change in the mean disability score, change in the proportion of participants who make use of walking aids, change in the mean Medical Research Council sum score, degree of pain relief and/or reduction of other positive sensory symptoms, change in the proportion of participants with pain or other positive sensory symptoms, and frequency of adverse effects.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed the results of the literature search and extracted details of trial methodology and outcome data of all potentially relevant trials.

MAIN RESULTS

We identified 39 studies and assessed them for possible inclusion in the review, but we excluded all of them because of insufficient quality or lack of relevance. We summarised evidence from non-randomised studies in the Discussion.

AUTHORS' CONCLUSIONS

Even though CIAP has been clearly described and delineated, no adequate randomised or quasi-randomised controlled clinical treatment trials have been performed. In their absence there is no proven efficacious drug therapy.

Health-related quality of life in patients receiving long-term opioid therapy: a systematic review with meta-analysis

PURPOSE

Over 25 million Americans reported having daily pain and between 5 and 8 million Americans used opioids to treat chronic pain in 2012. This is the first systematic review with meta-analysis to determine the effects of long-term opioid use on the Physical Component Summary (PCS) score and Mental Component Summary (MCS) scores of a Health-Related Quality of Life instrument in adults without opioid use disorder.

METHODS

The a priori eligibility criteria for the PubMed (MEDLINE), Scopus, and PsyINFO searches were (1) randomized controlled trial, (2) at least one opioid intervention group, (3) minimum of 4-week duration of opioid use, (4) comparative control group, and (5) adults ≥18 years that do not have dominant disease. The unit of analysis was the standardized mean difference effect size (Hedges's g). All results were pooled using random-effects models.

RESULTS

Of the 340 non-duplicate citations screened, 19 articles comprising 26 treatment comparisons and 6168 individuals (treatment n = 3160; comparators n = 3008 with duplicates removed) met the inclusion criteria for the systematic review. Thirteen treatment comparisons were available for the meta-analysis. Across all PCS analyses, small, statistically significant improvements were observed (opioid versus opioid only: g = 0.27, 95% CI 0.05-0.50, opioid versus placebo only: g = 0.18, 95% CI 0.08-0.28, and all studies combined: g = 0.22, 95% CI 0.11-0.32). There were small but not statistically significant changes on the MCS scores. Overall, high heterogeneity was present.

CONCLUSIONS

PCS scores improve with no change in MCS scores. However, long-term opioid trials are rare and only two trials included lasted longer than 1 year.

UPLC-MS-MS Determination of Dihydrocodeine in Human Plasma and Its Application to a Pharmacokinetic Study

A sensitive and rapid ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS-MS) method was developed to determine dihydrocodeine (DHC) in human plasma using diazepam as the internal standard (IS). Sample preparation was accomplished through a liquid-liquid extraction procedure with ethyl acetate. The analyte and IS were separated on an Acquity UPLC BEH C18 column (2.1 × 50 mm, 1.7 μm) with the mobile phase of acetonitrile and 1% formic acid in water with gradient elution at a flow rate of 0.4 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer equipped with positive-ion electrospray ionization by multiple reaction monitoring (MRM) of the transitions at m/z 302.3 → 199.2 for DHC and m/z 285.1 → 193.1 for IS. The linearity of this method was found to be within the concentration range of 0.5-100 ng/mL with a lower limit of quantification of 0.5 ng/mL. The overall run time was 4.0 min. The method herein described was superior to previous methods and was successfully applied to the pharmacokinetic study of DHC in healthy Chinese volunteers after oral administration.

Dihydrocodeine: safety concerns

Dihydrocodeine (DHC) is a semi-synthetic analogue of codeine, which was formed by the hydrogenation of the double tie in the main chain of the codeine molecule - instead of a double bond between carbons 7 and 8 DHC possesses a single bond. DHC is used as an analgesic and antitussive agent and for the management of dyspnea and opioid addiction. Limited data is available on the potency of DHC to other opioids. The analgesic effect of DHC is similar to codeine and approximately twice as potent as tramadol for an oral route. In contrast to codeine and tramadol, DHC analgesia seem to be irrespective of CYP2D6 activity due to parent compound analgesic effects, multiple metabolic pathways and limited role of dihydromorphine in DHC analgesia. As the drug is commonly available appropriate titration and dosing and knowledge of its metabolism and possible adverse effects are important for safe prescription of DHC.

The Number of Ratings Needed for Valid Pain Assessment in Clinical Trials: Replication and Extension

OBJECTIVES

To provide additional empirical findings regarding the number of pain ratings needed to obtain valid measures for assessing outcomes in pain clinical trials.

DESIGN

Secondary analyses of data from a clinical study examining the effects of psychological treatments on pain. Eleven adults with multiple sclerosis and chronic pain reported on four domains of pain intensity (current pain and 24-hour recalled worst, least, and average pain) on four occasions before and after receiving 16 sessions of psychological pain treatments. We evaluated the reliability and validity of four single ratings and 16 different composite scores.

RESULTS

Many of the single pain ratings were inadequately reliable while almost all of the composite scores, including the scores created from two ratings, evidenced adequate to excellent reliability. There was a noticeable increase in validity (ability to detect treatment effects) as the number of ratings used increased from one to two. However, there was little change in the validity as the number of items used to create composite scores increased from 2 to 3 or more. The findings also indicated that the scores assessing recalled worst pain were more valid than the scores assessing any of the other pain intensity domains.

CONCLUSIONS

Composite pain intensity scores created from two individual ratings of recalled pain appear to be adequately valid for detecting treatment effects. Moreover, the findings indicate that the selection of the pain intensity domain to use as a primary outcome variable may play a more important role than increasing reliability by obtaining more assessments; specifically, ratings of recalled worst pain may be more valid for detecting treatment effects than ratings of average pain.

Pharmacological treatment of pain: future trends and novel insights

The pharmacological treatment of chronic pain is generally hampered by a limited clinical outcome. Hence, there is a strong need for new therapeutic concepts considering the identification of novel targets and related drugs, but also optimization of established therapeutic regimes through individualization. In this issue, focused on "Pain," we discuss some of the recent new concepts in pain treatment, understanding of pain heterogeneity, and subsequent optimization of analgesic treatment, but also novel insights into interactions of nonopioids.