Gabapentinoid Benefit and Risk Stratification: Mechanisms Over Myth

Pilot RCT comparing low-dose naltrexone, gabapentin and placebo to reduce pain among people with HIV with alcohol problems

BACKGROUND

To estimate the effects on pain of two medications (low-dose naltrexone and gabapentin) compared to placebo among people with HIV (PWH) with heavy alcohol use and chronic pain.

METHODS

We conducted a pilot, randomized, double-blinded, 3-arm study of PWH with chronic pain and past-year heavy alcohol use in 2021. Participants were recruited in St. Petersburg, Russia, and randomized to receive daily low-dose naltrexone (4.5mg), gabapentin (up to 1800mg), or placebo. The two primary outcomes were change in self-reported pain severity and pain interference measured with the Brief Pain Inventory from baseline to 8 weeks.

RESULTS

Participants (N = 45, 15 in each arm) had the following baseline characteristics: 64% male; age 41 years (SD±7); mean 2 (SD±4) heavy drinking days in the past month and mean pain severity and interference were 3.2 (SD±1) and 3.0 (SD±2), respectively. Pain severity decreased for all three arms. Mean differences in change in pain severity for gabapentin vs. placebo, and naltrexone vs. placebo were -0.27 (95% confidence interval [CI] -1.76, 1.23; p = 0.73) and 0.88 (95% CI -0.7, 2.46; p = 0.55), respectively. Pain interference decreased for all three arms. Mean differences in change in pain interference for gabapentin vs. placebo, and naltrexone vs. placebo was 0.16 (95% CI -1.38, 1.71; p = 0.83) and 0.40 (95% CI -1.18, 1.99; p = 0.83), respectively.

CONCLUSION

Neither gabapentin nor low-dose naltrexone appeared to improve pain more than placebo among PWH with chronic pain and past-year heavy alcohol use.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NCT4052139).

Pregabalin use in forensic hospitals and prisons in German speaking countries-a survey study of physicians

Background

Pregabalin is a gamma-aminobutyric acid (GABA) analog that was approved in the EU in 2004 for the treatment of neuropathic pain, generalized anxiety disorder and epilepsy. Since its introduction, pregabalin abuse and misuse has increased significantly. In Switzerland, clinical reports suggest that pregabalin misuse is common among patients in forensic hospitals and prisons. However, data on pregabalin use is scarce, especially in these settings. Therefore, we conducted a study to explore patterns of pregabalin use among prison and forensic patients.

Methods

We used a questionnaire to survey physicians working in prison and forensic medicine in German-speaking countries. A total of 131 responses were received.

Results

According to the physicians' subjective assessment, 82.5% of them had observed a recent increase in pregabalin use by their patients and 89.1% of them reported that their patients requested pregabalin without a clear medical indication. Patients misusing pregabalin in combination with other illicit substances were observed by 93.3% of the physicians surveyed. According to 73.5% of the physicians surveyed, they had already encountered patients on pregabalin doses of more than 600 mg/day (the maximum recommended daily dose); the highest dose reported was 4,200 mg/day. According to 85.0% of physicians surveyed, they have observed patients experiencing withdrawal symptoms from pregabalin, with the most commonly reported symptoms being displeasure and high aggression. Regarding the nationality of pregabalin-misusing patients, 58.3% of the interviewed physicians reported to be rather in contact with foreign patients, mainly from Northwest Africa (Maghreb). Only 45.0% of the surveyed physicians prescribe pregabalin. Among patients who developed behavioral problems while taking pregabalin, none of the physicians (0.0%) showed a tendency to continue pregabalin at the same dose; all respondents chose to reduce/substitute/discontinue.

Conclusion

Our study has provided confirmatory evidence that the use of pregabalin presents a significant issue in forensic and prison medicine across German-speaking countries. Prescribing pregabalin in this field can compound use disorder problems and exacerbate challenges in daily life for those in forensic institutions or prisons. It is necessary that all physicians who prescribe pregabalin are clearly informed about the management (including the risks) of this drug.

Pregabalin Dependence and Management in a 55-Year-Old Female with Chronic Low Back Pain

This case report explores the complexities of managing chronic pain and the subsequent development of pregabalin dependence in a 55-year-old female patient with a prior history of vertebral fracture. Over a period of 10 years, the patient relied on a combination of Aceclofenac and pregabalin to alleviate her pain. An alternative treatment approach was implemented, involving adjustments to medication dosages and gradual tapering. Throughout the treatment process, interdisciplinary collaboration played a pivotal role in addressing unexpected symptoms such as facial movements and neck swelling. This case report highlights the significance of recognizing and addressing pregabalin dependence in patients with chronic pain.

Frailty: the perioperative and anesthesia challenges of an emerging pandemic

Frailty is a complex and multisystem biological process characterized by reductions in physiological reserve. It is an increasingly common phenomena in the surgical population, and significantly impacts postoperative recovery. In this review, we will discuss the pathophysiology of frailty, as well as preoperative, intraoperative, and postoperative considerations for frailty care. We will also discuss the different models of postoperative care, including enhanced recovery pathways, as well as elective critical care admission. With discoveries of new effective interventions, and advances in healthcare information technology, optimized pathways could be developed to provide the best care possible that meets the challenges of perioperative frailty.

Novel Drug Targets and Emerging Pharmacotherapies in Neuropathic Pain

Neuropathic pain is a debilitating condition characterized by abnormal signaling within the nervous system, resulting in persistent and often intense sensations of pain. It can arise from various causes, including traumatic nerve injury, neuropathy, and certain diseases. We present an overview of current and emerging pharmacotherapies for neuropathic pain, focusing on novel drug targets and potential therapeutic agents. Current pharmacotherapies, including tricyclic antidepressants, gabapentinoids, and serotonin norepinephrine re-uptake inhibitors, are discussed, as are emerging treatments, such as ambroxol, cannabidiol, and N-acetyl-L-cysteine. Additionally, the article highlights the need for further research in this field to identify new targets and develop more effective and targeted therapies for neuropathic pain management.

Acute withdrawal in the postoperative setting in a patient taking standard therapeutic doses of pregabalin

Pregabalin is a gamma-aminobutyric acid analog that binds to voltage-gated calcium channels within the central nervous tissues, inhibiting the release of many excitatory neurotransmitters. It is used to treat various conditions including postherpetic neuralgia and diabetic peripheral neuropathy. Recently, its use has increased as part of non-opioid pain management algorithms. Prolonged use in high doses of pregabalin is associated with physical dependency and abuse, which can be seen when the medication is abruptly stopped. This phenomenon has been seen in studies focused on patients having abused or grown dependent on pregabalin. However, this has not been documented in patients taking therapeutic levels in the perioperative setting. This case report highlights a patient who experienced acute withdrawal symptoms of pregabalin after coronary artery bypass and aortic root enlargement.

Effect of amoxicillin/clavulanic acid in attenuating pregabalin-induced condition place preference

Substance abuse is a worldwide problem with serious repercussions for patients and the communities where they live. Pregabalin (Lyrica), is a medication commonly used to treat neuropathic pain. Like other analgesic medications there has been concern about pregabalin abuse and misuse. Although it was initially suggested that pregabalin, like other gabapentinoids, has limited abuse liability, questions still remain concerning this inquiry. Changes in glutamate system homeostasis are a hallmark of adaptations underlying drug dependence, including down-regulation of the glutamate transporter 1 (GLT-1; SLC1A2) and the cystine/glutamate antiporter (xCT; SLC7A11). In this study, it was found that pregabalin (90 mg/kg) produces a conditioned place preference (CPP), indicative of reinforcing effects that suggest a potential for abuse liability. Moreover, like other drugs of abuse, pregabalin also produced alterations in glutamate homeostasis, reducing the mRNA expression of Slc1a2 and Slc7a11 in the nucleus accumbens (NAc) and medial prefrontal cortex (mPFC). Amoxicillin clavulanic acid, a β-lactam antibiotic, blocked the reinforcing effects of pregabalin and normalized glutamate homeostasis. These results suggest that pregabalin has abuse potential that should be examined more critically, and that, moreover, the mechanisms underlying these effects are similar to those of other drugs of abuse, such as heroin and cocaine. Additionally, these results support previous findings showing normalization of glutamate homeostasis by β-lactam drugs that provides a novel potential therapeutic approach for the treatment of drug abuse and dependence.

The Role of Gabapentinoids in the Substance Use Pattern of Adult Germans Seeking Inpatient Detoxification Treatment - A Pilot Study

To shed more light on the addictive power of the gabapentinoids (GPTs) gabapentin and pregabalin, we performed a structured face-to-face interview with GPT-users about DSM-IV-dependence-criteria (sedatives), consume-motives and cessation-needs. Among 100 patients consecutively admitted to a detoxification-ward, fifteen (15%) reported lifetime GPT-use (18-50 years old, 2 females): seven (7%) used gabapentin, twelve (12%) pregabalin and four had lifetime experiences with both GPTs. Of the seven gabapentin-users, three patients were dependent including one person with a spontaneous remission. Of the 12 pregabalin-users, five were dependent, including two persons with a spontaneous remission. Fourteen of fifteen cases reported GPT-use side-by-side with an opioid-use, mostly for sparing opioids. Twelve GPT-users additionally co-used benzodiazepines. In no case, a GPT was the reason for detoxification treatment or reported to be involved in an emergency event. Altogether, every 7^th patient (n = 15) of our inpatient detoxification-seeking sample reported GPT-use including 50% (n = 8) who were dependent. Among them, 35% (3/8) had been already spontaneously remitted. As GPT-users reported no cession-need and the vast majority were primarily affected by co-occurring opioid- and benzodiazepine-addiction, we assume that GPTs more likely played a bystander-role than mediating the addictive behavior of this population with multiple recreational drug use experience.

The association of gabapentin initiation and neurocognitive changes in older adults with normal cognition

Background: Gabapentin is increasingly prescribed to older adults, which raises concerns about its potential to cause neurocognitive changes. Therefore, we aimed to examine the association of gabapentin use with neurocognitive changes (i.e., cognitive decline, functional status decline, and motor function change) in older adults. Methods: We conducted a retrospective cohort study using the National Alzheimer's Coordinating Center Uniform Data Set (UDS; September 2005-March 2021 data freeze). From the eligible sample (≥age 65 years), we identified cognitively normal new-users of gabapentin and the visit they initiated gabapentin (i.e., index visit). Initiators were matched to randomly selected nonusers on year of UDS enrollment and visit number from enrollment to index. Cognitive decline was defined as any increase in the Clinical Dementia Rating global score (CDRGLOB) and as a 1-point increase in CDR sum of boxes (CDR-SB). Functional status decline was defined as a 3-point increase in the sum of the Functional Activities Questionnaire (FAQ) and as 0.3-point increase in mean FAQ. Decline in motor function was defined as new clinician reports of gait disorder, falls, and slowness. To mitigate confounding and selection bias, we used joint stabilized inverse probability of treatment weights and stabilized inverse probability of censoring weights. All analyses were conducted comparing index to index+1 and index+2 visits. Results: From the eligible UDS participants (N = 23,059), we included 480 initiators (mean age [SD]: 78.7 [6.9]; male 34.4%); 4,320 nonusers (78.3 [7.0]; 34.4%). Gabapentin initiation was significantly associated with cognitive/functional status decline: worsening CDRGLOB at index+1 visit (odds ratio [95% confidence interval]: 1.55 [1.07, 2.25]); CDR-SB at index+1 visit (1.94 [1.22, 3.09]); and mean of FAQ at index+2 visit (1.78 [1.12, 2.83]). After excluding initiators with extant motor dysfunction (n = 21), we identified 459 initiators (78.7 [6.9]; 34.0%) and 4,131 nonusers (78.2 [6.9]; 34.7%); in this sample, gabapentin initiation was associated with increased falls at the index+2 visit (2.51 [1.19, 5.31]). Conclusion: Gabapentin initiation was significantly associated with deleterious neurocognitive changes among older adults with initially normal cognition. Further studies are needed to examine the risk/benefit of prescribing gabapentin in older adults.

Pregabalin for chemotherapy-induced neuropathy: background and rationale for further study

Chemotherapy-induced neuropathy is difficult to manage, and the pain associated with neuropathy is poorly responsive to gabapentin in a randomized trial. Duloxetine is the only drug that has been found to be effective in reducing pain from chemotherapy neuropathy. In this qualitative review, the use of pregabalin for chemotherapy-induced neuropathy is discussed including the rationale and pharmacological reasons why pregabalin should be considered in a large, randomized placebo-controlled trial.

Association of State-Imposed Restrictions on Gabapentin with Changes in Prescribing in Medicare

BACKGROUND

Between August 2016 and July 2018, three states classified gabapentin as a Schedule V drug and nine states implemented prescription drug monitoring program (PDMP) regulation for gabapentin. It is highly unusual for states to take drug regulation into their own hands. The impact of these changes on gabapentin prescribing is unclear.

OBJECTIVE

To determine the effect of state-imposed regulation on gabapentin prescribing for Medicare Part D enrollees from 2013 to 2018.

DESIGN

Population-based difference-in-difference(DID) analysis study utilizing the Medicare Part D Prescriber Public Use File.

PARTICIPANTS

All eligible Medicare Part D prescribers excluding those outside of the fifty states and the District of Columbia were included in our analysis. Prescriber data and key sociodemographic variables were organized by state and year. States with a gabapentin schedule change or PDMP regulation enacted before 2019 were included in the intervention group. For the Schedule V DID analysis, a control group of the ten highest opioid-prescribing states was used.

INTERVENTIONS

States with gabapentin schedule changes or PDMP regulation before January 1, 2019, were included and compared to control states that did not implement these policies.

MAIN MEASURES

Total days' supply of gabapentin per enrollee per year was the primary outcome variable.

KEY RESULTS

The mean total days' supply of gabapentin per enrollee increased 41% from 19.71 to 27.81 total days' supply per enrollee per year between 2013 and 2018. After adjustment, Schedule V gabapentin regulation resulted in a reduction of 8.37 total days of gabapentin prescribed per enrollee (95% confidence interval of - 10.34 to - 6.39). In contrast, PDMP regulation resulted in a reduction of 1.01 total days of gabapentin prescribed per enrollee (95% confidence interval of - 1.74 to - 0.29).

CONCLUSIONS

Classifying gabapentin as a Schedule V drug results in substantial reduction in total days prescribed whereas PDMP regulation results in modest reduction.

A snapshot on the usage pattern of gabapentinoids in Oman

Background

Since their introduction as adjunct anticonvulsants, the use of gabapentinoids (gabapentin and pregabalin) has increased substantially worldwide to include a wide range of clinical conditions. Various reports have demonstrated that they possess addiction liability and can produce effects similar to traditional recreational drugs, such as significant euphoric effects, enhanced sociability, and relaxation. However, there is limited information on the use of these agents in the Middle East.

Objectives

Here, we describe the usage pattern of gabapentinoids at Sultan Qaboos University Hospital, a tertiary care medical institution in Oman.

Methods

Adult patients (≥18 years) who were prescribed gabapentinoids for six months (March-August 2019) were included in this retrospective cross-sectional study. Indications and dosing regimens were reviewed according to the Food and Drug Administration labeling. Controlled and restricted drugs were reviewed using Oman National Formulary. Institutional ethical approval was obtained before conducting the study.

Results

We analyzed 291 prescriptions. The mean (standard deviation, SD) age was 60.5 years (SD = 13.0) with the age group of ≥60 years being the most common (190, 65.3%). Most of patients were females (178, 61.2%). The majority of prescriptions were for outpatients (85.8%). Drugs were prescribed as refill and follow-up in 116 (40.0%) and 97 (33.4%) of prescriptions, respectively. Diabetic peripheral neuropathy (50, 79.4%) was the most labeled indication for both. Off-label use was 128 (51.8%) and 31 (70.5%) for pregabalin and gabapentin, respectively, with lower back pain as being the most common indication for both drugs. A total of 54 (19.0%) patients were using at least one of the psychotropic drugs.

Conclusions

Our findings indicate that gabapentinoids are frequently prescribed for off-label use. Awareness programs and the establishment of policy for the use of these drugs are required to ensure their rational use and prevent misuse and/or abuse.

Pharmacotherapy for Spine-Related Pain in Older Adults

As the population ages, spine-related pain is increasingly common in older adults. While medications play an important role in pain management, their use has limitations in geriatric patients due to reduced liver and renal function, comorbid medical problems, and polypharmacy. This review will assess the evidence basis for medications used for spine-related pain in older adults, with a focus on drug metabolism and adverse drug reactions. A PubMed/OVID search crossing common spine, neck, and back pain terms with key words for older adults and geriatrics was combined with common drug classes and common drug names and limited to clinical trials and age over 65 years. The results were then reviewed with identification of commonly used drugs and drug categories: nonsteroidal anti-inflammatories (NSAIDs), acetaminophen, corticosteroids, gabapentin and pregabalin, antispastic and antispasmodic muscle relaxants, tricyclic antidepressants (TCAs), serotonin-norepinephrine reuptake inhibitors (SNRIs), tramadol, and opioids. Collectively, 138 double-blind, placebo-controlled trials were the focus of the review. The review found a variable contribution of high-quality studies examining the efficacy of medications for spine pain primarily in the geriatric population. There was strong evidence for NSAID use with adjustments for gastrointestinal and renal risk factors. Gabapentin and pregabalin had mixed evidence for neuropathic pain. SNRIs had good evidence for neuropathic pain and a more favorable safety profile than TCAs. Tramadol had some evidence in older patients, but more so in persons aged < 65 years. Rational therapeutic choices based on geriatric spine pain diagnosis are helpful, such as NSAIDs and acetaminophen for arthritic and myofascial-based pain, gabapentinoids or duloxetine for neuropathic and radicular pain, antispastic agents for myofascial-based pain, and combination therapy for mixed etiologies. Tramadol can be well tolerated in older patients, but has risks of cognitive and classic opioid side effects. Otherwise, opioids are typically avoided in the treatment of spine-related pain in older adults due to their morbidity and mortality risk and are reserved for refractory severe pain. Whenever possible, beneficial geriatric spine pain pharmacotherapy should employ the lowest therapeutic doses with consideration of polypharmacy, potentially decreased renal and hepatic metabolism, and co-morbid medical disorders.

How prevalent and severe is addiction on GABAmimetic drugs in an elderly German general hospital population? Focus on gabapentinoids, benzodiazepines, and z-hypnotic drugs

OBJECTIVE

Gabapentinoids (GPT) are reported to be increasingly misused by opioid- and polydrug-users, but the addictive potential of GPT outside of these populations remains understudied. Investigations comparing GPT abuse and dependence liability to that of other commonly prescribed Central Nervous System-acting medications are therefore warranted. We provide a comparison of GPT-abuse/dependence to that of other GABAmimetics within an elderly population.

DESIGN

DSM-IV-TR-based data (previously prospectively collected by SKID-I-interview) from a random sample of elderly patients admitted to a metropolitan German general hospital were reviewed. The prevalence and severity of GPT, benzodiazepine (BDZ), and z-hypnotic drug (ZD)-abuse and -dependence were compared, stratified also by mono-substance (no concurrent current or previous substance use) and de novo-substance (first)-abuse and -dependence states.

RESULTS

Among 400 patients (75 ± 6.4 years old; 63% females), neither current nor past abuse of BDZ, ZD or GPT, nor other illicit substances was observed. Dependence upon BDZ, ZD or GPT was observed among 55 (13.75%) individuals. The related lifetime/12-month prevalence-rates were: dependence condition (BDZ: 7%/2.45%; ZD: 4.25%/4.25%; GPT: 2.75/2.5%); mono-dependence condition (BDZ: 2.25%/0.75%; ZD: 1%/1%, GPT: 0%/0%); de novo-dependence condition (BDZ: 2.75%/1.75%; ZD: 1%/1%, GPT: 0.5%/0.5%). Opioid analgesic-dependence (N = 43/400) was significantly more frequently linked with BDZ than with GPT (p < 0.01) [Correction added on 29 December 2021, after first online publication: In the sentence 'Opioid analgesic-dependence…', the term 'and ZD' has been deleted]. For all three GABAmimetic classes, most mono- and de novo-dependence states were mild-to-moderate and lasted 2-6 years (median).

CONCLUSION

GABAmimetic-dependence was usually mixed with other substance-dependences. Every third to fourth instance of BDZ- or ZD-dependence was a mono-dependence condition, while a pure GPT-dependence was absent in this elderly (and illicit substance-naïve) population.

Prevalence of Gabapentinoids and Central Nervous System Depressant Drugs, and Their Association with Risk Factors for Respiratory Depression in Primary Care Patients

BACKGROUND AND OBJECTIVES

Warnings have been published regarding an increased risk of severe respiratory depression in patients receiving gabapentinoids either alone or in combination with opioids and/or anxiolytics/hypnotics, especially in individuals with a respiratory risk factor. The aim is to report the prevalence of the use of gabapentinoids alone and associated with central nervous system depressant drugs, and possible associated risk factors for respiratory depression, in order to identify the most fragile population and establish intervention strategies.

METHODS

We performed a cross-sectional study using computerized prescription records from the northern area of Barcelona at Catalan Institute of Health for 363,007 inhabitants registered during 2021. Patients aged ≥ 18 years with one or more gabapentinoid prescription were included. Age, gender, polypharmacy, adjusted morbidity groups, quantity of chronic diseases, and the number of consultations per year were independent variables. Four age categories were defined (18-64 years, then 64-74, 75-84, and those aged 85 years or older). Descriptive and inferential statistics were employed. Level of statistical significance was 5% (p ≤ 0.05). For the analysis, the SPSS program (version 22) was employed.

RESULTS

Of the study sample, 9218 were prescribed gabapentidoids. Overall prevalence of use was 3.0% (women 3.6%, men 2.4%). On the whole, women used more drugs than men. In contrast to their younger counterparts, consumption increased 2.6 times, 3.8 times, and 4.0 times in the 65-74 age group, 75-84 age group, and those aged ≥ 85 years, respectively. Mean age was 65.59 (±15.80) years. Polypharmacy (5-9 drugs) was present in 41.7% of the patients and extreme polypharmacy (≥ 10 drugs) was present in 39.3% of the patients. Regarding renal function, 2396 patients (25.9%) had glomerular filtration that required dose adjustment (76.1% with gabapentin and 23.8% with pregabalin). In 141 patients (5.9%), a total daily dose higher than that authorized (109 with gabapentin, 29 with pregabalin) had been prescribed. The prescription of gabapentinoids combined with opioids and/or anxiolytics/hypnotics was significantly associated with (i) polypharmacy (5-9 drugs, OR: 3.42 [95% CI 3.00-3.88]; ≥ 10 drugs, OR 8.72 [95% CI 7.42-10.25]); (ii) quantity of chronic diseases, OR: 1.14 (95% CI 1.11-1.17); (iii) augmented number of consultations/year, OR: 1.01 (95% CI 1.00-1.01); (iv) female gender, OR: <  1 for men, OR: 0.66 (95% CI 0.60-0.73); (v) being elderly: 65-74 years, OR: 0.71 (95% CI 0.62-0.81); 75-84 years, OR: 0.62 (95% CI 0.54-0.71); ≥85 years, OR: 0.68 (95% CI 0.58-0.81); and (vi) adjusted morbidity groups, OR: 0.90 (95% CI 0.88-0.92), (p <  0.0001).

CONCLUSION

Exposure to gabapentinoids occurs in a non-negligible percentage of the population. Greater numbers of combinations of gabapentinoids and opioids and/or anxiolytics/hypnotics were associated with polypharmacy, quantity of chronic diseases, and augmented number of consultations, but not with male gender, older age, and adjusted morbidity groups.

Pharmacologic Management of Persistent Pain in Cancer Survivors

Improvements in screening, diagnosis and treatment of cancer has seen cancer mortality substantially diminish in the past three decades. It is estimated there are almost 20 million cancer survivors in the USA alone, but some 40% live with chronic pain after completing treatment. While a broad definition of survivorship that includes all people living with, through and beyond a cancer diagnosis—including those with active cancer—is often used, this narrative review primarily focuses on the management of pain in people who are disease-free after completing primary cancer treatment as adults. Chronic pain in this population needs a different approach to that used for people with a limited prognosis. After describing the common chronic pain syndromes caused by cancer treatment, and the pathophysiologic mechanisms involved, the pharmacologic management of entities such as post-surgical pain, chemotherapy-induced neuropathy, aromatase inhibitor musculoskeletal syndrome and checkpoint inhibitor-related pain are described. The challenges  associated with opioid prescribing in this population are given special attention. Expert guidelines on pain management in cancer survivors now recommend a combination of pharmacologic and non-pharmacologic modalities, and these are also briefly covered.

Perioperative care in open aortic vascular surgery: A Consensus Statement by the Enhanced Recovery after Surgery (ERAS®) Society and Society for Vascular Surgery

The Society for Vascular Surgery and the Enhanced Recovery After Surgery (ERAS®) Society formally collaborated and elected an international, multi-disciplinary panel of experts to review the literature and provide evidence-based recommendations related to all of the health care received in the perioperative period for patients undergoing open abdominal aortic operations (both transabdominal and retroperitoneal approaches, including supraceliac, suprarenal, and infrarenal clamp sites, for aortic aneurysm and aortoiliac occlusive disease). Structured around the ERAS® core elements, 36 recommendations were made and organized into preadmission, preoperative, intraoperative, and postoperative recommendations.

Extracorporeal Treatment for Gabapentin and Pregabalin Poisoning: Systematic Review and Recommendations From the EXTRIP Workgroup

Toxicity from gabapentin and pregabalin overdose is commonly encountered. Treatment is supportive, and the use of extracorporeal treatments (ECTRs) is controversial. The EXTRIP workgroup conducted systematic reviews of the literature and summarized findings following published methods. Thirty-three articles (30 patient reports and 3 pharmacokinetic studies) met the inclusion criteria. High gabapentinoid extracorporeal clearance (>150mL/min) and short elimination half-life (<5 hours) were reported with hemodialysis. The workgroup assessed gabapentin and pregabalin as "dialyzable" for patients with decreased kidney function (quality of the evidence grade as A and B, respectively). Limited clinical data were available (24 patients with gabapentin toxicity and 7 with pregabalin toxicity received ECTR). Severe toxicity, mortality, and sequelae were rare in cases receiving ECTR and in historical controls receiving standard care alone. No clear clinical benefit from ECTR could be identified although major knowledge gaps were acknowledged, as well as costs and harms of ECTR. The EXTRIP workgroup suggests against performing ECTR in addition to standard care rather than standard care alone (weak recommendation, very low quality of evidence) for gabapentinoid poisoning in patients with normal kidney function. If decreased kidney function and coma requiring mechanical ventilation are present, the workgroup suggests performing ECTR in addition to standard care (weak recommendation, very low quality of evidence).

Developing nociceptor-selective treatments for acute and chronic pain

Despite substantial efforts dedicated to the development of new, nonaddictive analgesics, success in treating pain has been limited. Clinically available analgesic agents generally lack efficacy and may have undesirable side effects. Traditional target-based drug discovery efforts that generate compounds with selectivity for single targets have a high rate of attrition because of their poor clinical efficacy. Here, we examine the challenges associated with the current analgesic drug discovery model and review evidence in favor of stem cell–derived neuronal-based screening approaches for the identification of analgesic targets and compounds for treating diverse forms of acute and chronic pain.

Zero Patient-controlled Analgesia is an Achievable Target for Postoperative Rapid Recovery Management of Adolescent Idiopathic Scoliosis Patients

STUDY DESIGN

Retrospective review.

OBJECTIVE

The objective of this study was to report on one institution's use of single bolus micro-dose intrathecal morphine as part of a rapid recovery pathway during posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) and its comparison to patients whose pain was controlled with patient-controlled analgesia (PCA).

SUMMARY OF BACKGROUND DATA

Narcotic substance addiction has risen across all patient populations, including pediatrics. Narcotics have been historically used in complex spine surgeries as a measure of pain control, predominantly provided as PCA and additional take-home medication.

METHODS

AIS patients undergoing PSF from 2015 to 2019 were reviewed. In 2018, we instituted a standardized rapid recovery pathway for scoliosis patients undergoing PSF utilizing micro-dose intrathecal morphine (ITM-RRP). Before this, traditional protocol with PCA was used for postoperative management. Perioperative data, morphine consumption and prescription refill requests were compared.

RESULTS

There were 373 AIS patients total in this study, of which 250 patients were in the PCA group and 123 in the ITM-RRP Group. Preoperative Cobb angles (P = 0.195), as well as levels fused (P = 0.481) and body mass index (P = 0.075) were similar. 69.4% of ITM-RRP patients had a length of stay ≤3 days, significantly >11.6% of PCA patients (P < 0.001). ITM-RRP patients began ambulating significantly earlier with 84.6% patients out of bed by postoperative day 1 versus 8% PCA patients (P < 0.001). Additionally, ITM-RRP patients had significantly lower VAS pain scores with activity and earlier initial bowel movements (P < 0.001).Postoperative emesis was similar (P = 0.11). No patients had pruritus, respiratory depression, or required supplemental oxygenation.

CONCLUSION

This is the first study to show that a rapid recovery protocol utilizing single micro-dose ITM with oral analgesics have adequate recovery, significantly better postoperative pain control and superior perioperative outcomes to traditional protocols using PCA in the AIS population following PSF.Level of Evidence: 3.

Trends in the Utilization and Dose of Gabapentinoids in Combination With Opioids in an Injured Worker Population Between 2008 and 2018

OBJECTIVE

To determine long term (11 year) trends in gabapentin and pregabalin prescribing among workers' compensation claimants at various opioid dose combinations (low, medium, high, and very high) in Louisiana.

METHOD

A longitudinal study of 18,737 claimants who filled any prescriptions between 2008 and 2018.

RESULTS

The proportion of claimants prescribed opioids alone at all dose levels decreased dramatically. The proportion claimants prescribed the combination of low dose opioids and low dose gabapentinoids increased (7.7% to 10.9%). Prescribing higher daily doses of gabapentinoids was associated with higher daily doses of opioids. Gabapentinoid prescribing was associated with continued prescribing of medium and high dose opioids as claims matured.

CONCLUSIONS

Overall opioid prescribing decreased over time, while prescribing low dose opioids with gabapentinoids, increased.

Input-dependent synaptic suppression by pregabalin in the central amygdala in male mice with inflammatory pain

Pregabalin (PGB) is a synthetic amino acid compound most widely prescribed for chronic peripheral and central neuropathic pain. PGB is a ligand for the α2δ1 subunit of voltage-dependent calcium channels, and its binding reduces neurotransmitter release and thus inhibits synaptic transmission. The central nucleus of the amygdala (CeA) is a kernel site for the enhanced nociception-emotion link in chronic pain. The nociceptive information is conveyed to the CeA via the following two pathways: 1) the pathway arising from the basolateral amygdala (BLA), which carries nociceptive information mediated by the thalamocortical system, and 2) that arising from the external part of the pontine lateral parabrachial nucleus (LPB), that forms the final route of the spino-parabrachio-amygdaloid pathway that conveys nociceptive information directly from the superficial layer of the spinal dorsal horn. We compared the effects of PGB on the excitatory postsynaptic currents of neurons in the right CeA in response to electrical stimulation of BLA and LPB pathways using the whole-cell patch-clamp technique. Inflammatory pain was induced by intraplantar injection of formalin solution at the left hind paw. At eight hours post-formalin, PGB reduced EPSCs amplitude of the BLA-to-CeA synaptic transmission, accompanied by a significant increase in the PPR, suggesting a decreased release probability from the presynaptic terminals. In addition, these effects of PGB were only seen in inflammatory conditions. PGB did not affect the synaptic transmission at the LPB-to-CeA pathway, even in formalin-treated mice. These results suggest PGB improves not simply the aberrantly enhanced nociception but also various pain-associated cognitive and affective consequences in patients with chronic nociplastic pain.

At the intersection of sleep deficiency and opioid use: mechanisms and therapeutic opportunities

Due to the ongoing opioid epidemic, innovative scientific perspectives and approaches are urgently needed to reduce the unprecedented personal and societal burdens of nonmedical and recreational opioid use. One promising opportunity is to focus on the relationship between sleep deficiency and opioid use. In this review, we examine empirical evidence: (1) at the interface of sleep deficiency and opioid use, including hypothesized bidirectional associations between sleep efficiency and opioid abstinence; (2) as to whether normalization of sleep deficiency might directly or indirectly improve opioid abstinence (and vice versa); and (3) regarding mechanisms that could link improvements in sleep to opioid abstinence. Based on available data, we identify candidate sleep-restorative therapeutic approaches that should be examined in rigorous clinical trials.

The gabapentinoid drugs and their abuse potential

The gabapentinoid drugs, gabapentin and pregabalin, are first-line treatments for neuropathic pain. The epidemics of chronic pain and opioid misuse have given rise to the widespread use of non-opioid drugs such as the gabapentinoids for treatment. Unfortunately, the widespread use of gabapentinoid drugs has resulted in reports of misuse and abuse. Here we summarize the clinical reports of gabapentinoid abuse in different patient populations to help inform clinical practice of chronic pain management.

Exercise Reduces Pain and Deleterious Histological Effects in Fibromyalgia-like Model

Fibromyalgia (FM) is characterized by chronic pain and associated comorbidities such as fatigue, anxiety, depression, and sleep disorders. There is a large amount of evidence regarding the benefits of physical exercise in controlling chronic pain. However, there is no consensus on which exercise modality is most suitable and the real benefits of this intervention to treat FM symptoms. The present study investigated the analgesic and antidepressant effects and morphophysiological responses induced by different physical exercise (aerobic and strength protocols) during the experimental model of FM. Spontaneous pain, mechanical hyperalgesia, thermal allodynia, depression-related behavior, and locomotor activity were evaluated weekly, as well as the morphological evaluation of the spinal cord and dorsal root ganglion. Aerobic and strength training protocols consistently abolished nociceptive behaviors, reducing spontaneous pain scores, cold allodynia, and frequency of response to mechanical hyperalgesia. The strength exercise modulated the depressive-like behavior. Finally, our data demonstrated that physical exercise performed for two weeks increased the number of glial cells in the dorsal root horn. However, it was not sufficient to control the other deleterious effects of the reserpine model on the spinal cord and the dorsal root. Together, these results demonstrated that different physical exercise modalities, when performed regularly in mice, proved to be effective and safe non-pharmacological alternatives for the treatment of FM. However, some gaps have yet to be studied regarding the neuroadaptive effects of physical exercise.

European clinical practice recommendations on opioids for chronic noncancer pain - Part 2: Special situations

BACKGROUND

Opioid use for chronic non-cancer pain (CNCP) is under debate. In the absence of pan-European guidance on this issue, a position paper was commissioned by the European Pain Federation (EFIC).

METHODS

The clinical practice recommendations were developed by eight scientific societies and one patient self-help organization under the coordination of EFIC. A systematic literature search in MEDLINE (up until January 2020) was performed. Two categories of guidance are given: Evidence-based recommendations (supported by evidence from systematic reviews of randomized controlled trials or of observational studies) and Good Clinical Practice (GCP) statements (supported either by indirect evidence or by case-series, case-control studies and clinical experience). The GRADE system was applied to move from evidence to recommendations. The recommendations and GCP statements were developed by a multiprofessional task force (including nursing, service users, physicians, physiotherapy and psychology) and formal multistep procedures to reach a set of consensus recommendations. The clinical practice recommendations were reviewed by five external reviewers from North America and Europe and were also posted for public comment.

RESULTS

The European Clinical Practice Recommendations give guidance for combination with other medications, the management of frequent (e.g. nausea, constipation) and rare (e.g. hyperalgesia) side effects, for special clinical populations (e.g. children and adolescents, pregnancy) and for special situations (e.g. liver cirrhosis).

CONCLUSION

If a trial with opioids for chronic noncancer pain is conducted, detailed knowledge and experience are needed to adapt the opioid treatment to a special patient group and/or clinical situation and to manage side effects effectively.

SIGNIFICANCE

If a trial with opioids for chronic noncancer pain is conducted, detailed knowledge and experience are needed to adapt the opioid treatment to a special patient group and/or clinical situation and to manage side effects effectively. A collaboration of medical specialties and of all health care professionals is needed for some special populations and clinical situations.

Safety of treatment options available for postoperative pain

IntroductionPostoperative pain is one of the most common adverse events after surgery and has been shown to increase the risk of other complications. On the other hand, liberal opioid use in the perioperative period is also associated with risk of adverse events. The current consensus is therefore to provide multimodal, opioid minimizing analgesia after surgery.Areas CoveredIn this review, we will discuss the benefits and risks associated with non-opioid analgesics, including non-steroidal anti-inflammatory drugs, gabapentinoids, ketamine, α-2 agonists, and corticosteroids. In addition, we will discuss the general and block-specific risks associated with regional anesthestic techniques.Expert OpinionAdverse events associated with non-opioid analgesics are rare outside their specific contraindicated patient groups, especially when dosed appropriately. α-2 agonists can cause transient hypotension and bradycardia, and gabapentinoids may cause sedation in higher risk patient populations. Regional anesthesia techniques are generally safe when done by an experienced practitioner. We therefore encourage the development of standardized multimodal analgesic protocols, which may facilitate opioid minimization and lead to better patient outcomes.

Gabapentinoid Abuse in France: Evidence on Health Consequences and New Points of Vigilance

Introduction: Gabapentinoid drugs (gabapentin and pregabalin) are widely used worldwide for epileptic and pain disorders. First signals of gabapentinoid abuse occurred in the last decade. This study aims to describe clinical characteristics of gabapentinoid use related disorders and health consequences in France. Materials and Methods: We designed a multisource investigation reviewing data reported to the French Addictovigilance Network (FAN) with pregabalin and gabapentin from 2010 to 2019. Information was obtained through the analysis of Spontaneous Reports (SRs) notified by health professionals and the pharmacoepidemiological surveys OSIAP (suspicious prescriptions forms indicators of potential abuse), OPPIDUM (observation of illicit drugs and misuse of psychotropic medications), DRAMES (death related to prescription drugs and other substances), and DTA (toxic deaths due to analgesics). Results: Over 2010-2019 period, were collected: (i) 265 SRs (258 pregabalin; 7 gabapentin); (ii) 816 forged prescription forms (805 pregabalin, 10 gabapentin, 1 involving both drugs); (iii) 145 cases of gabapentinoid use in people who use drugs (121 pregabalin; 24 gabapentin) and (iv) 31 cases of gabapentinoid-related deaths (25 pregabalin; 6 gabapentin). Risk factors of gabapentinoid abuse were opioid use disorders or psychiatric history, but cases of primary abuse in subjects without any substance abuse history were observed. Adverse outcomes concern almost exclusively pregabalin, with coma, dyspnea, convulsion, and conduction disorders. Treatment demands increased from 10.6% in 2018 to 23.1% in 2019, with pregabalin cited as the first substance leading to addictological care in the 2019 OPPIDUM survey. Gabapentinoid-related deaths increased over time. Pregabalin has become the first drug mentioned in forged prescriptions in 2019 (23.8% of OSIAP), while it ranked at the 15th position in 2017 (2.6%). Discussion: This study shows the importance of addictovigilance monitoring for gabapentinoids. Addictovigilance data helped to make visible the gabapentinoid-abuse related health harms (hospitalization for serious neurologic, psychiatric or cardiac effects, requests for addictological support and deaths) and to confirm the intrinsic abuse potential of pregabalin. These data highlight new points of vigilance considering observed primary abuse. At this point in France, the risk of abuse and related complications is very apparent with pregabalin. Still, it is identical to that observed elsewhere with gabapentin.