Full Opioid Agonists and Tramadol: Pharmacological and Clinical Considerations

Chiropractic spinal manipulation and likelihood of tramadol prescription in adults with radicular low back pain: a retrospective cohort study using US data

OBJECTIVES

Patients receiving chiropractic spinal manipulation (CSM) for low back pain (LBP) are less likely to receive any opioid prescription for subsequent pain management. However, the likelihood of specifically being prescribed tramadol, a less potent opioid, has not been explored. We hypothesised that adults receiving CSM for newly diagnosed radicular LBP would be less likely to receive a tramadol prescription over 1-year follow-up, compared with those receiving usual medical care.

DESIGN

Retrospective cohort study.

SETTING

US medical records-based dataset including >115 million patients attending academic health centres (TriNetX, Inc), queried 9 November 2023.

PARTICIPANTS

Opioid-naive adults aged 18-50 with a new diagnosis of radicular LBP were included. Patients with serious pathology and tramadol use contraindications were excluded. Variables associated with tramadol prescription were controlled via propensity matching.

INTERVENTIONS

Patients were divided into two cohorts dependent on treatment received on the index date of radicular LBP diagnosis (CSM or usual medical care).

PRIMARY AND SECONDARY OUTCOME MEASURES

Risk ratio (RR) for tramadol prescription (primary); markers of usual medical care utilisation (secondary).

RESULTS

After propensity matching, there were 1171 patients per cohort (mean age 35 years). Tramadol prescription was significantly lower in the CSM cohort compared with the usual medical care cohort, with an RR (95% CI) of 0.32 (0.18 to 0.57; p<0.0001). A cumulative incidence graph demonstrated that the reduced incidence of tramadol prescription in the CSM cohort relative to the usual medical care cohort was maintained throughout 1-year follow-up. Utilisation of NSAIDs, physical therapy evaluation and lumbar imaging was similar between cohorts.

CONCLUSIONS

This study found that US adults initially receiving CSM for radicular LBP had a reduced likelihood of receiving a tramadol prescription over 1-year follow-up. These findings should be corroborated by a prospective study to minimise residual confounding.

The association between polypharmacy and health-related quality of life among older adults with prostate cancer

INTRODUCTION

Older adults with prostate cancer (PC) are at risk of polypharmacy, which further complicates disease management and health-related quality of life (HRQoL). This study evaluated the association between polypharmacy and HRQoL among Medicare beneficiaries with PC.

MATERIALS AND METHODS

This observational, retrospective study analyzed data from the Surveillance, Epidemiology, and End Results (SEER) Medicare Health Outcomes Survey (MHOS) data resource. Beneficiaries aged ≥65 and enrolled in Medicare Advantage Organizations were included if they had a PC diagnosis and continuously enrolled in Part D for 12 months prior to the completion of MHOS. Polypharmacy was determined based on the unique number of concurrent Part D prescriptions during 12 months before survey: no polypharmacy (NP, n = 0-4), polypharmacy (PP, n = 5-9), and excessive polypharmacy (EPP, n ≥ 10). HRQoL was assessed using the Physical and Mental Component Summary T-scores (PCS and MCS, respectively) in MHOS. ANOVA and Pearson's Chi-Square tests were performed to assess variances between polypharmacy and continuous/categorical variables. Multivariate linear regression models with generalized estimating equations were used to assess the association between polypharmacy and HRQoL. The severely impaired HRQoL cohort was identified based on normalized z-scores of PCS and MCS. Odds ratios were calculated to prioritize drug-drug and class-class pairs associated with patients with severely impaired HRQoL.

RESULTS

Data from 16,573 beneficiaries (24,126 records) showed that 44.4% had PP and 10.1% had EPP. Beneficiaries with PP and EPP had significantly lower mean PCS and MCS scores compared to those without polypharmacy (p < 0.001). After adjusting for covariates, beneficiaries with EPP had clinically significantly lower PCS (adjusted marginal difference: -8.47 [-9.00, -7.94]) and MCS (adjusted marginal difference: -4.32 [-4.89, -3.75]) compared to the NP group. Top-ranked drug-drug pairs like tiotropium bromide and oxycodone/acetaminophen exhibited significant associations with HRQoL decline. Analysis of class-class pairs highlighted (1) corticosteroid hormone receptor agonists and opioid agonists and (2) benzodiazepines and adrenergic beta2-agonists as having significant associations with HRQoL decline.

DISCUSSION

Polypharmacy exhibits a significant association with HRQoL declines among older adults with PC.

Quantitative determination of R/S-methadone in human serum using ultra-high performance supercritical fluid chromatography-tandem mass spectrometry: A method for routine use

Methadone has two enantiomers, which exhibit differences in pharmacological effects, with R-methadone being the active and S-methadone the inactive enantiomer. A robust, simple and rapid method for chiral separation of the two enantiomers in serum samples using ultra-high performance supercritical fluid chromatography-tandem mass spectrometry (UHPSFC-MSMS) has been developed and validated. Enantiomeric separation was achieved using a Chiralpak IH-3 column with a mobile phase consisting of CO2 and 30mM ammonium acetate in methanol/water (98/2, v/v). Runtime was 4 minutes. Sample preparation was semi-automated using a Hamilton ML Star robot with protein precipitation, and phospholipid removal was carried out using a Waters OSTRO™ 96-well plate. The calibration range was 50.0-1,500 nM for each enantiomer. The between-assay relative standard deviations were in the range of 1.2-3.6%. Matrix effects ranged from 99% to 115% corrected with internal standard. The method has been implemented in our laboratory and has proven to be a robust and reliable method for determining the ratio of R/S-methadone in authentic patient samples.

Co-crystal of Tramadol-Celecoxib Versus Tramadol or Placebo for Acute Moderate-to-Severe Pain After Oral Surgery: Randomized, Double-Blind, Phase 3 Trial (STARDOM1)

INTRODUCTION

Co-crystal of tramadol-celecoxib (CTC) is the first analgesic co-crystal for acute pain. This completed phase 3 multicenter, double-blind trial assessed the efficacy and safety/tolerability of CTC in comparison with that of tramadol in the setting of moderate-to-severe pain up to 72 h after elective third molar extraction requiring bone removal.

METHODS

Adults (n = 726) were assigned randomly to five groups (2:2:2:2:1): orally administered twice-daily CTC 100 mg (44 mg rac-tramadol hydrochloride/56 mg celecoxib; n = 164), 150 mg (66/84 mg; n = 160) or 200 mg (88/112 mg; n = 160); tramadol 100 mg four times daily (n = 159); or placebo four times daily (n = 83). Participants in CTC groups also received twice-daily placebo. The full analysis set included all participants who underwent randomization. The primary endpoint was the sum of pain intensity differences over 0 to 4 h (SPID0-4; visual analog scale). Key secondary endpoints included 4-h 50% responder and rescue medication use rates. Safety endpoints included adverse events (AEs), laboratory measures, and Opioid-Related Symptom Distress Scale (OR-SDS) score.

RESULTS

All CTC doses were superior to placebo (P < 0.001) for primary and key secondary endpoints. All were superior to tramadol for SPID0-4 (analysis of covariance least squares mean differences [95% confidence interval]: - 37.1 [- 56.5, - 17.6], - 40.2 [- 59.7, - 20.6], and - 41.7 [- 61.2, - 22.2] for 100, 150, and 200 mg CTC, respectively; P < 0.001) and 4-h 50% responder rate. Four-hour 50% responder rates were 32.9% (CTC 100 mg), 33.8% (CTC 150 mg), 40.6% (CTC 200 mg), 20.1% (tramadol), and 7.2% (placebo). Rescue medication use was lower in the 100-mg (P = 0.013) and 200-mg (P = 0.003) CTC groups versus tramadol group. AE incidence and OR-SDS scores were highest for tramadol alone.

CONCLUSIONS

CTC demonstrated superior pain relief compared with tramadol or placebo, as well as an improved benefit/risk profile versus tramadol.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02982161; EudraCT number, 2016-000592-24.

Co-crystal of tramadol-celecoxib (CTC) for acute moderate-to-severe pain

OBJECTIVE

This narrative review aims to provide a clinical perspective on the potential role of co-crystal of tramadol-celecoxib (CTC) in the management of acute moderate-to-severe pain by synthesizing the available preclinical and clinical data, with emphasis on phase 3 trials.

METHODS

A non-systematic literature review was performed using a targeted PubMed search for articles published between January 1, 2000, and May 2, 2023; all publication types were permitted, and selected articles were limited to those published in English. Search results were manually reviewed to identify references based on their preclinical and clinical relevance to CTC and management of acute moderate-to-severe pain.

RESULTS

The crystalline structure of CTC alters the physicochemical properties of tramadol and celecoxib, modifying their pharmacokinetics. If taken in a free combination, tramadol reduces absorption of celecoxib. Conversely, administration of CTC slows tramadol absorption and lowers its maximum plasma concentration, while increasing celecoxib plasma concentration through its enhanced release. In clinical studies across models of acute moderate-to-severe pain, CTC demonstrated an early onset of analgesia, with improved efficacy and lower rescue medication use, compared with either agent alone. CTC's safety profile was in line with that expected for the individual components; no additive effects were observed. CTC exhibited tramadol-sparing effects, with efficacy seen at lower daily/cumulative opioid doses vs. tramadol alone.

CONCLUSIONS

Results from phase 3 trials suggest that the modified physicochemical properties of tramadol and celecoxib in CTC translate into an improved clinical benefit-risk profile, including fewer opioid-related adverse effects due to lower overall opioid dosing.

Total alditols from Cistanche deserticola attenuate functional constipation by regulating bile acid metabolism

HEADINGS ETHNOPHARMACOLOGICAL RELEVANCE

Functional constipation (FC), characterized by chronic constipation, significantly impacts physiological function and induces psychological stress in patients. However, current clinical treatment options for FC are currently limited. Cistanche deserticola, a traditional Chinese medicine that promotes intestinal moisture and bowel relaxation, contains cistanche total alditol extract (CTAE) as its primary active extract. However, the production of CTAE, its overall efficacy, and potential mechanisms for treating FC have yet to been investigated.

AIM OF THE STUDY

This study aimed to reveal the overall efficacy and potential mechanism of action of CTAE in rats with FC using a combination of stable preparation, pharmacodynamics, non-targeted metabolomics, bile acid metabolomics, and western blotting.

MATERIALS AND METHODS

Fourteen batches of CTAE underwent quality testing. A rat model of FC was developed using diphenoxylate tablets. The comprehensive pharmacodynamic effects of CTAE on FC were evaluated using fecal characteristics (wet weight, dry weight, and water content), intestinal transmission (colonic EMG amplitude, colonic EMG frequency, propulsion length, and propulsion rate), serum and colon biochemical indicators, distribution of interstitial cells of Cajal (ICC), and pathological examination. Non-targeted metabolomics was performed to assess the changes in endogenous metabolite profiles induced by CTAE. Bile acid metabolomics and western blotting analyses were employed to validate the potential mechanisms of action of CTAE.

RESULTS

CTAE, with a total content of betaine, mannitol, D-fructose, glucose, and sucrose of (75.67 ± 3.73) %, significantly enhanced intestinal transit, regulated neurotransmitters, increased the expression of c-kit in ICC, and alleviated intestinal inflammation in rats with FC. Non-targeted metabolomics revealed that CTAE significantly alleviated FC-induced metabolic disorders, mainly the biosynthesis of primary bile acids. Targeted metabolomic analysis confirmed that CTAE regulated FC-induced bile acid disorders. Western-blotting results confirmed that CTAE increased the expression of CYP8B1, FGF15, TGR5, and FXR, thereby modulating bile acid synthesis and enterohepatic circulation.

CONCLUSION

CTAE demonstrates significant therapeutic effects on FC, primarily through the regulation of bile acid synthesis and enterohepatic circulation. These findings provide a promising foundation for the development and clinical application of novel CATE-based drugs.

Maintenance of mitochondrial function by sinapic acid protects against tramadol-induced toxicity in isolated mitochondria obtained from rat brain

It is reported that tramadol can induce neurotoxic effects with the production of DNA damage, mitochondrial dysfunction, and oxidative stress. The current study aimed to evaluate the potential role of mitochondrial impairment in the pathogenesis of tramadol-induced neurotoxicity, and protective effect of sinapic acid (SA) against it in isolated mitochondria from rat brain. Mitochondria were isolated and were incubated with toxic concentrations (100 μM) of tramadol and then cotreated with tramadol + SA (10, 50, and 100 μM). Biomarkers of mitochondrial toxicity including succinate dehydrogenases (SDH) activity, reactive oxygen species (ROS), lipid peroxidation (LPO), mitochondrial membrane potential (MMP), GSH depletion, and mitochondrial swelling were assessed. Our results showed a significant decrease in SDH activity, and a significant increase in ROS, LPO, GSH depletion, MMP collapse, and mitochondrial swelling was detected in tramadol group. We observed that 50 and 100 μM SA cotreatment for 1 h efficiently ameliorated tramadol-caused damage in mitochondrial dysfunction, accumulation of ROS, LPO, GSH depletion, depolarization of mitochondrial membrane potential, and mitochondrial swelling. These data suggest that mitochondrial impairment and oxidative stress are mechanisms involved in the pathogenesis of tramadol-induced neurotoxicity. Also, results indicate that SA antagonizes against tramadol-induced mitochondrial toxicity and suggest SA may be a preventive/therapeutic agent for tramadol-induced neurotoxicity complications.

Pills and the damage done: the opioid epidemic as man-made crisis

The prescription opioid epidemic has slowly evolved over the past quarter century with increasingly detrimental consequences for public health. Man-made crises are often unforeseen and characterized by a situation without natural causes where - because of human intent, error, negligence, or the failure of manmade systems - the level of needs in the population exceeds available resources to counter the problem. This paper presents the prescription opioid epidemic as a man-made crisis and explores the public health impact of opioid manufacturers and other industries producing commodities with addictive potential as a shared vulnerability among countries. We examine this concept within the framework of the commercial determinants of health. We address three key aspects of the commercial determinants of health: (1) Cross-industry mechanisms, (2) policy inertia, and (3) the role of industry in science. Within cross-industry mechanisms, we explore parallels between prescription opioid epidemic and unhealthy commodity industries in terms of marketing, corporate use of misinformation, and diversionary tactics. Next, we examine how policy inertia has dominated the slow response to this man-made crisis. Lastly, we discuss how results from clinical trials are used as a key marketing strategy for drugs. The origins of the prescription opioid epidemic may be traced to innovations in drug development with the promise of improved pain management. However, through multiple factors, including fraudulent marketing from pharmaceutical industry and policy inertia, the resulting crisis represents a multi-system failure of regulation exploited by corporate greed.

IUPHAR review - Data-driven computational drug repurposing approaches for opioid use disorder

Opioid Use Disorder (OUD) is a chronic and relapsing condition characterized by the misuse of opioid drugs, causing significant morbidity and mortality in the United States. Existing medications for OUD are limited, and there is an immediate need to discover treatments with enhanced safety and efficacy. Drug repurposing aims to find new indications for existing medications, offering a time-saving and cost-efficient alternative strategy to traditional drug discovery. Computational approaches have been developed to further facilitate the drug repurposing process. In this paper, we reviewed state-of-the-art data-driven computational drug repurposing approaches for OUD and discussed their advantages and potential challenges. We also highlighted promising repurposed candidate drugs for OUD that were identified by computational drug repurposing techniques and reviewed studies supporting their potential mechanisms of action in treating OUD.

Repetitive transcranial magnetic stimulation in central post-stroke pain: current status and future perspective

Central post-stroke pain (CPSP) is an incapacitating disorder that impacts a substantial proportion of stroke survivors and can diminish their quality of life. Conventional therapies for CPSP, including tricyclic antidepressants, anticonvulsants, and opioids, are frequently ineffective, necessitating the investigation of alternative therapeutic strategies. Repetitive transcranial magnetic stimulation (rTMS) is now recognized as a promising noninvasive pain management method for CPSP. rTMS modulates neural activity through the administration of magnetic pulses to specific cortical regions. Trials analyzing the effects of rTMS on CPSP have generated various outcomes, but the evidence suggests possible analgesic benefits. In CPSP and other neuropathic pain conditions, high-frequency rTMS targeting the primary motor cortex (M1) with figure-eight coils has demonstrated significant pain alleviation. Due to its associaton with analgesic benefits, M1 is the most frequently targeted area. The duration and frequency of rTMS sessions, as well as the stimulation intensity, have been studied in an effort to optimize treatment outcomes. The short-term pain relief effects of rTMS have been observed, but the long-term effects (> 3 months) require further investigation. Aspects such as stimulation frequency, location, and treatment period can influence the efficacy of rTMS and ought to be considered while planning the procedure. Standardized guidelines for using rTMS in CPSP would optimize therapy protocols and improve patient outcomes. This review article provides an up-to-date overview of the incidence, clinical characteristics, outcome of rTMS in CPSP patients, and future perspective in the field.

Efficacy and safety of parenteral and local application of tramadol in mandibular third molar extraction: a qualitative systematic review of current evidence

PURPOSE

To assess the efficacy and safety of perioperative parenteral administration or submucosal infiltration of tramadol for perioperative pain control on the basis of pain intensity or analgesics consumption and perioperative outcomes in mandibular third molar surgery.

MATERIAL-METHODS

An electronic database search was conducted up to 10 November 2022 to retrieve all randomized controlled trials (RCTs), assessing the analgesic efficacy of parenteral use of tramadol implemented as an adjunct to local anesthesia or intraoperative sedation/general anesthesia, in surgical extraction of mandibular third molars. Modified Jadad scale and Cochrane bias tool were used for the qualitative appraisal.

RESULTS

Nineteen RCTs were selected for qualitative analysis. Nine studies involved intravenous, and 5 intramuscular administration of tramadol, while 5 evaluated submucosal infiltration with tramadol. Intravenous or intramuscular tramadol provided a weaker analgesic effect compared with non-steroidal anti-inflammatory drugs (NSAIDs), while intravenous tramadol induced an enhanced analgesic effect than oral tramadol. Parenteral administration of tramadol improved the quality of postoperative analgesia versus placebo. No notable adverse effects were recorded.

CONCLUSIONS

Parenteral or submucosal infiltration of tramadol constitutes an effective and safe alternative analgesic approach in surgical extraction of mandibular third molars, yet the nociceptive effect of this analgesic modality could not supersede that of NSAIDs.

TRIAL REGISTRATION

PROSPERO No CRD42021227574.

Comparison of adjuvant therapy with midazolam, paracetamol, tramadol, or magnesium sulfate during intravenous regional anesthesia with ropivacaine: A randomized clinical trial

Background

Intravenous (IV) regional anesthesia is an easy, safe, reliable, and efficient option for inducing anesthesia during surgeries but with tourniquet-related pain. This study aimed to evaluate midazolam, paracetamol, tramadol, and magnesium sulfate administration as adjuvants with ropivacaine on pain relief and hemodynamic changes in IV regional anesthesia.

Methods

A randomized, double-blind, placebo-controlled trial was conducted in subjects undergoing forearm surgery with IV regional anesthesia. The block randomization method was used to assign eligible participants to each of five study groups. Hemodynamic parameters were assessed before applying the tourniquet, at prespecified time points (5, 10, 15, and 20 min), then and every subsequent 10 min until surgery completion. A Visual Analog Scale was used to assess pain severity at baseline followed by every 15 min until completion of the surgery, and after tourniquet deflation every 30 min to 2 h, and at 6, 12, and 24 h postoperative. Data were analyzed using Chi-square and analysis of variance with repeated data testing.

Results

The shortest onset and the longest duration of sensory block were observed in the tramadol group and the shortest onset of motor block in the midazolam group (P < 0.001). Pain score was estimated to be significantly lower in the tramadol group at the time of tourniquet application and release, and 15 min to 12 h after tourniquet release (P < 0.05). In addition, the lowest dose of pethidine consumption was observed in the tramadol group (P < 0.001).

Conclusion

Tramadol appeared to be able to effectively relieve pain, shorten the onset of sensory block, prolong the duration of sensory block, and achieve the lowest consumption of pethidine.

Influence of Perioperative Anesthesia on Cancer Recurrence: from Basic Science to Clinical Practice

PURPOSEOF REVIEW

In this review, we will summarize the effects of these perioperative anesthetics and anesthetic interventions on the immune system and tumorigenesis as well as address the related clinical evidence on cancer-related mortality and recurrence.

RECENT FINDINGS

Cancer remains a leading cause of morbidity and mortality worldwide. For many solid tumors, surgery is one of the major therapies. Unfortunately, surgery promotes angiogenesis, shedding of circulating cancer cells, and suppresses immunity. Hence, the perioperative period has a close relationship with cancer metastases or recurrence. In the perioperative period, patients require multiple anesthetic management including anesthetics, anesthetic techniques, and body temperature control. Preclinical and retrospective studies have found that these anesthetic agents and interventions have complex effects on cancer outcomes. Therefore, well-planned, prospective, randomized controlled trials are required to explore the effects of different anesthetics and techniques on long-term outcomes after cancer surgery. Due to the conflicting effects of anesthetic management on cancer recurrence, further preclinical and clinical trials are required and beneficial to the development of systemic cancer therapies.

Celecoxib-tramadol co-crystal in patients with moderate-to-severe pain following bunionectomy with osteotomy: A phase 3, randomized, double-blind, factorial, active- and placebo-controlled trial

BACKGROUND

Celecoxib-tramadol co-crystal (CTC) is a first-in-class analgesic co-crystal of celecoxib and racemic tramadol with an improved pharmacologic profile, conferred by the co-crystal structure, compared with its active constituents administered alone/concomitantly.

AIM

We evaluated CTC in moderate-to-severe acute postoperative pain.

MATERIALS AND METHODS

This randomized, double-blind, factorial, active- and placebo-controlled phase 3 trial (NCT03108482) was conducted at 6 US clinical research centers. Adults with moderate-to-severe acute pain following bunionectomy with osteotomy were randomized to oral CTC (200 mg [112 mg celecoxib/88 mg rac-tramadol hydrochloride] every 12 h), tramadol (50 mg every 6 h), celecoxib (100 mg every 12 h), or placebo for 48 h. Patients, investigators, and personnel were blinded to assignment. The primary endpoint was the 0-48 h sum of pain intensity differences (SPID0-48) in all randomized patients. Pain intensity was assessed on a 0-10 numerical rating scale (NRS). Safety was analyzed in patients who received study medication. Funded by ESTEVE Pharmaceuticals.

RESULTS

In 2017 (March to November), 1323 patients were screened and 637 randomized to CTC (n = 184), tramadol (n = 183), celecoxib (n = 181), or placebo (n = 89). Mean baseline NRS was 6.7 in all active groups. CTC had a significantly greater effect on SPID0-48 (least-squares mean: -139.1 [95% confidence interval: -151.8, -126.5]) than tramadol (-109.1 [-121.7, -96.4]; p < 0.001), celecoxib (-103.7 [-116.4, -91.0]; p < 0.001), or placebo (-74.6 [-92.5, -56.6]; p < 0.001). Total treatment-emergent adverse events (TEAEs) were 358 for CTC and 394 for tramadol. Drug-related TEAEs occurred in 37.7% patients in the CTC group, compared with 48.6% in the tramadol group. There were no serious TEAEs/deaths.

CONCLUSION

CTC provided greater analgesia than comparable daily doses of tramadol and celecoxib, with similar tolerability to tramadol. CTC is approved in the United States.

Review of the Treatments for Central Neuropathic Pain

Central neuropathic pain (CNP) affects millions worldwide, with an estimated prevalence of around 10% globally. Although there are a wide variety of treatment options available, due to the complex and multidimensional nature in which CNP arises and presents symptomatically, many patients still experience painful symptoms. Pharmaceutical, surgical, non-invasive, cognitive and combination treatment options offer a generalized starting point for alleviating symptoms; however, a more customized approach may provide greater benefit. Here, we comment on the current treatment options that exist for CNP and further suggest the need for additional research regarding the use of biomarkers to help individualize treatment options for patients.

Efficacy and safety of co-crystal of tramadol-celecoxib (CTC) in acute moderate-to-severe pain after abdominal hysterectomy: A randomized, double-blind, phase 3 trial (STARDOM2)

BACKGROUND

STARDOM2 is a randomized, double-blind, phase 3 trial evaluating the efficacy and safety of co-crystal of tramadol-celecoxib (CTC)-a first-in-class analgesic co-crystal comprising racemic tramadol hydrochloride and celecoxib in a supramolecular network that modifies their pharmacokinetic properties-for the management of acute postoperative pain (NCT03062644; EudraCT:2016-000593-38).

METHODS

Patients with moderate-to-severe pain following abdominal hysterectomy were randomized 2:2:2:2:2:1 to oral CTC 100 mg (rac-tramadol hydrochloride 44 mg/celecoxib 56 mg) twice daily (BID); CTC 150 mg (66/84 mg) BID; CTC 200 mg (88/112 mg) BID; immediate-release tramadol 100 mg four times daily (QID); celecoxib 100 mg BID; or placebo, for 5 days. The primary endpoint was the sum of pain intensity differences over 0-4 h (SPID_0-4 ). Key secondary endpoints were rescue medication use within 4 h, 50% response rate at 4 h, and safety/tolerability.

RESULTS

Of 1355 patients enrolled, 1138 were randomized (full analysis set) and 1136 treated (safety analysis set). In the prespecified gatekeeping analysis of SPID_0-4 , CTC 200 mg was not superior to tramadol but showed non-inferior efficacy (p < 0.001) that was sustained throughout the 120-h period, despite a 5-day cumulative tramadol administration of 880 mg with CTC 200 mg BID versus 2000 mg with tramadol 100 mg QID. Treatment-emergent adverse events (TEAEs) and severe TEAEs were less common with CTC 200 mg versus tramadol. Treatment-related TEAEs were 14.4% with CTC 200 mg and 23.6% with tramadol.

CONCLUSIONS

Although the study did not meet its primary endpoint, CTC 200 mg showed a clinically relevant improvement in overall benefit/risk profile versus tramadol alone, with considerably lower cumulative opioid exposure.

SIGNIFICANCE

In the randomized, double-blind, phase 3 STARDOM2 trial-in acute moderate-to-severe pain after abdominal hysterectomy-the novel co-crystal of tramadol-celecoxib (CTC) 200 mg BID was superior to placebo and non-inferior to tramadol 100 mg QID. Although superiority to tramadol was not reached, CTC 200 mg BID exposed patients to lower cumulative opioid (tramadol) doses than tramadol (100 mg QID) alone, with fewer treatment-emergent adverse events. CTC 200 mg thus has a clinically relevant improved benefit/risk profile compared with tramadol alone.

The Effect of Preoperative Tramadol Use on Postoperative Opioid Prescriptions After Primary Total Hip and Knee Arthroplasty: An Institutional Experience of 11,000 Patients

BACKGROUND

Preoperative opioid use increases opioid consumption postoperatively, but the effect of tramadol is poorly understood.

METHODS

We retrospectively reviewed 11,667 patients undergoing primary unilateral THA and TKA at a single institution. Preoperatively, there were 8,201 opioid-naïve patients (70.3%), 1,315 on tramadol (11.3%), 1,408 on narcotics (12.1%) and 743 on narcotics and tramadol (6.3%). We compared morphine milligram equivalents (MMEs) used during hospitalization, prescribed at discharge, and refilled during the first 90 days. We used multivariate analysis to assess whether preoperative tramadol use was associated with increased number of refills and total refilled MMEs.

RESULTS

Total in-hospital MMEs and daily MMEs was lowest for the opioid naïve patients and significantly increased for the remaining three groups (total in-hospital use: 119, 152, 211, and 196 MMEs, respectively-P < .001) (daily in-hospital use: 66, 74, 100, and 86 MMEs, respectively-P < .001). Opioid refill rate was significantly higher for all patients who were not opioid naïve (32%, 42%, 41%, and 52%, respectively-P < .001). Total MMEs prescribed after discharge was lowest for opioid naïve patients (477, 528, 590 and 658, respectively-P < .001). Logistic and linear regression controlling for age, sex, history of anxiety/depression revealed that THA patients taking tramadol preoperatively were 2.5 times more likely to require post-discharge refills and refilled 80 additional MMEs than opioid naïve patients (P < .001).

CONCLUSION

Tramadol is not recommended for pain beforeTKA or THA, and surgeons and patients should be aware that it is associated with a substantial increase in postoperative opioid use.

Tramadol prescribed at discharge is associated with lower odds of chronic opioid use after elective total joint arthroplasty

INTRODUCTION

We aimed to study the association between tramadol prescribed at discharge (after elective total hip and knee arthroplasty (THA/TKA) surgery) and chronic opioid use postoperatively.

METHODS

This retrospective cohort study queried the Truven MarketScan database and identified patients who underwent an elective THA/TKA surgery between 2016 and 2018 and were prescribed opioids at discharge (n=81 049). Multivariable analysis was conducted to study the association between tramadol prescription at discharge and chronic opioid use, with additional analysis adjusting for the amount of opioids prescribed in oral morphine equivalents. Chronic opioid use was defined as filling ≥10 opioid prescriptions or prescriptions for ≥120 pills within the period from 90 days to 1 year after surgery.

RESULTS

Overall, tramadol was prescribed at discharge in 11.0% of all THA/TKA cases. Of those, 26.9% and 73.1% received tramadol only or tramadol with another opioid, respectively. Chronic opioid use was observed in 5.4% of cases. After adjustment for relevant covariates, prescription of tramadol combined with another opioid at discharge was associated with lower odds of chronic opioid use comparing to prescription of other opioids (OR 0.69 CI 0.61 to 0.78).

DISCUSSION

Among patients undergoing elective THA/TKA surgery and discharged with a prescription of opioids, we found that prescription of tramadol combined with another opioid was associated with lower odds of chronic opioid use. This finding must be considered in the context of the tramadol's pharmacology, as well-described genetic differences in metabolism that can make it ineffective in many patients, while for patients with ultrarapid metabolism can cause drug-drug interactions and adverse events, including feelings of high and seizures.

A Multimodal Clinical Approach for the Treatment of Bone Metastases in Solid Tumors

Context

Bone metastasis (BM) is a frequent complication of cancer, representing the third most common site of secondary spread in solid cancers behind the lung and liver. Bone metastasis is found in up to 90% of prostate and breast cancer patients. They can cause significant complications, such as pathological fractures and paralysis of the spine, which decrease daily functioning and quality of life (QoL) and worsen prognosis. The growing life expectancy of cancer patients due to improvements in systemic therapies may further increase BM's eventuality and clinical burden in cancer patients.

Evidence Acquisition

Four physicians from five different specialties were interviewed and resumed the most relevant literature of the last 20 years focusing on pain treatment in BM patients.

Results

Treatment for BM ideally involves various types of specialists and assessments. The disease status and patient background should be considered, requiring holistic care and expertise from various medical specialties.

Conclusions

Interventional, nuclear medicine, radiotherapy, and mini-invasive techniques can be safe and effective for relieving pain and modifying health-related QoL in BM patients.

The Influence of Analgesic Modalities on Postoperative Cancer Recurrence

The potential for cancer cells to grow and to metastasize depends on complex interactions between inflammatory signals and pathways, immune cells, and elements of the stromal tissue in which they invade. Related to the nature of many cancers, the probability of recurrence can potentially be quite high for some patients. Immunology, lifestyle modifications, timing of disease, genetics, age, gender, and race are only a handful of ways the likelihood of cancer recurrence can be influenced. The quantity, or density, of certain immunological cells or factors, plays a role in the propagation of cancer cells. Opioids are often used in cancer patients for acute postoperative and chronic pain management. While they can produce significant pain relief, the type of analgesic utilized is important, as it may influence cancer propagation. In this regard, certain opioids have been found to increase T regulatory cells while suppressing NK cell function. Morphine may promote tumor neovascularization and expansion. Fentanyl administration significantly diminishes NK-cells and CD8+ cytotoxic T-cells. In a recent meta-analysis, propofol-based anesthesia improved both cancer-free survival and overall survival. COX inhibitors have also shown promise in persevering cancer immune function, as in literature involving ketorolac and celecoxib. In summary, inhaled anesthesia and opioids may contribute to a pro-tumor metastasis environment also known as cancer propagation; whereas propofol and COX inhibitors may provide a better alternative to reduce cancer recurrence and propagation.

Novel Local Anesthetics in Clinical Practice: Pharmacologic Considerations and Potential Roles for the Future

The treatment of pain, both acute and chronic, has been a focus of medicine for generations. Physicians have tried to develop novel ways to effectively manage pain in surgical and post-surgical settings. One intervention demonstrating efficacy is nerve blocks. Single-injection peripheral nerve blocks (PNBs) are usually preferred over continuous PNBs, since they are not associated with longer lengths of stay. The challenge of single injection PNBs is their length of duration, which at present is a major limitation. Novel preparations of local anesthetics have also been studied, and these new preparations could allow for extended duration of action of anesthetics. An emerging preparation of bupivacaine, exparel, uses a multivesicular liposomal delivery system which releases medication in a steady, controlled manner. Another extended-release local anesthetic, HTX-011, consists of a combination of bupivacaine and low-dose meloxicam. Tetrodotoxin, a naturally occurring reversible site 1 sodium channel toxin derived from pufferfish and shellfish, has shown the potential to block conduction of isolated nerves. Neosaxitoxin is a more potent reversible site 1 sodium channel toxin also found in shellfish that can also block nerve conduction. These novel formulations show great promise in terms of the ability to prolong the duration of single injection PNBs. This field is still currently in development, and more researchers will need to be done to ensure the efficacy and safety of these novel formulations. These formulations could be the future of pain management if ongoing research continues to prove positive effects and low side effect profiles.

The Effect of Pneumoperitoneum-induced Hypertension During Laparoscopic Cholecystectomy Under General Anesthesia on Postoperative Pain: A Randomized Clinical Trial

Background: Acute postoperative pain is a significant cause of morbidities. This study aimed to evaluate the effect of intraoperative blood pressure during laparoscopic cholecystectomy under general anesthesia on postoperative pain in patients without underlying disorders. Methods: In this randomized clinical trial, 72 patients undergoing general anesthesia for elective laparoscopic cholecystectomy were randomly assigned into two groups: Group A with higher than baseline preoperative blood pressure (MAP allowed to increase up to 20% higher than baseline MAP by inducing pneumoperitoneum) and group B with normal to low blood pressure (MAP deliberately controlled at a tight limit from normal baseline MAP values to 20% less than baseline by titrating TNG infusion). The Visual Analog Scale (VAS) after 2, 8, 12, and 24 hours of surgery, and the total dose of meperidine used to manage postoperative pain were recorded and compared between the two groups. Results: The pain scores in group A were significantly lower than group B (P = 0.001). The postoperative analgesia request time was different between the two groups (P = 0.53). During the first 24 hours, the total meperidine consumption dose in group A was significantly lower than in group B (P = 0.001). Conclusions: High intraoperative blood pressure may affect the postoperative pain after laparoscopic cholecystectomy and lead to less postoperative pain score and analgesic requirements.

Comparison of Intraperitoneal Bupivacaine and Intravenous Ketorolac for Postoperative Pain Management Following Laparoscopic Cholecystectomy

Background

Postoperative pain following laparoscopic cholecystectomy (LC) arises from incision sites and residual intraperitoneal CO₂ gas. Opioids as a class of pain-relieving drugs are broadly used to control pain after LC; however, these drugs can cause various side effects.

Objectives

The purpose of this study was to compare the efficacy of intraperitoneal injection of bupivacaine with that of intravenous ketorolac in managing postoperative pain in patients who had undergone LC.

Methods

This randomized, double-blind clinical trial was carried out on patients who had undergone LC. Ninety patients who had undergone elective LC were randomly divided into 3 groups (n = 30 for each group). Group A received 40 mL of 0.25% bupivacaine solution intraperitoneally at the end of the operation; group B received 30 mg of ketorolac intravenously 30 minutes before surgery and every 8 hours after surgery, and patients in group C received normal saline intraperitoneally and intravenous injection. The patients were postoperatively assessed for Visual Analog Scale (VAS) scores, postoperative opioid consumption, shoulder pain, side effects (sedation, nausea, and vomiting), and satisfaction. The data were analyzed using SPSS. P values < 0.05 were considered significant.

Results

The intraperitoneal injection of bupivacaine and intravenous injection of ketorolac were significantly effective in reducing postoperative abdominal pain, shoulder pain, and incidence of nausea and vomiting compared to the placebo group (P < 0.001). Although intraperitoneal bupivacaine and intravenous ketorolac had no significant difference in pain relief compared with each other, patients in both bupivacaine and ketorolac groups were significantly more satisfied with their analgesia compared to the control group (P < 0.001).

Conclusions

Intraperitoneal injection of bupivacaine and intravenous injection of ketorolac both are safe and effective methods to control pain, nausea, and vomiting after LC.

Conolidine: A Novel Plant Extract for Chronic Pain

: Pain, the most common symptom reported among patients in the primary care setting, is complex to manage. Opioids are among the most potent analgesics agents for managing pain. Since the mid-1990s, the number of opioid prescriptions for the management of chronic non-cancer pain (CNCP) has increased by more than 400%, and this increased availability has significantly contributed to opioid diversion, overdose, tolerance, dependence, and addiction. Despite the questionable effectiveness of opioids in managing CNCP and their high rates of side effects, the absence of available alternative medications and their clinical limitations and slower onset of action has led to an overreliance on opioids. Conolidine is an indole alkaloid derived from the bark of the tropical flowering shrub Tabernaemontana divaricate used in traditional Chinese, Ayurvedic, and Thai medicine. Conolidine could represent the beginning of a new era of chronic pain management. It is now being investigated for its effects on the atypical chemokine receptor (ACK3). In a rat model, it was found that a competitor molecule binding to ACKR3 resulted in inhibition of ACKR3’s inhibitory activity, causing an overall increase in opiate receptor activity. Although the identification of conolidine as a potential novel analgesic agent provides an additional avenue to address the opioid crisis and manage CNCP, further studies are necessary to understand its mechanism of action and utility and efficacy in managing CNCP.

Adding Dexmedetomidine to Bupivacaine in Ultrasound-guided Thoracic Paravertebral Block for Pain Management after Upper Abdominal Surgery: A Double-blind Randomized Controlled Trial

Background

Paravertebral blocks are one of the possible postoperative pain management modalities after laparotomy. Adjuvants to local anesthetics, including alpha agonists, have been shown to lead to better pain relief and increased duration of analgesia.

Objectives

The aim of this study is to examine the effect of adding dexmedetomidine to bupivacaine for ultrasound-guided paravertebral blocks in laparotomy.

Methods

In this double-blind, randomized controlled trial (RCT), we enrolled 42 patients scheduled for T6 to T8 thoracic paravertebral block (TPVB) for analgesia after laparotomy. The patients were randomly assigned into two groups of BD (bupivacaine 2.5 mg/mL 20 mL plus dexmedetomidine 100 µg) and B (bupivacaine 20 mL alone). Following surgery, intravenous fentanyl patient-controlled analgesia was initiated. The numerical rating scale (NRS) for pain, sedation score, total analgesic consumption, time to first analgesic requirement, side effects (such as nausea and vomiting), respiratory depression, and patients’ satisfaction during the first 48 hours of evaluation were compared in the two groups.

Results

Pain scores and mean total analgesic consumption at the first 48 hours in the BD group were significantly lower than Group B (P = 0.03 and P < 0.001, respectively). The time of first analgesic request was significantly longer in BD group (P < 0.001). Sedation scores and side effects did not differ significantly between the two groups.

Conclusions

Adding dexmedetomidine to bupivacaine for TPVB after laparotomy yielded better postoperative pain management without significant complications.

Supraclavicular vs. Infraclavicular Brachial Plexus Nerve Blocks: Clinical, Pharmacological, and Anatomical Considerations

: Peripheral nerve blocks (PNB) have become standard of care for enhanced recovery pathways after surgery. For brachial plexus delivery of anesthesia, both supraclavicular (SC) and infraclavicular (IC) approaches have been shown to require less supplemental anesthesia, are performed more rapidly, have quicker onset time, and have lower rates of complications than other approaches (axillary, interscalene, etc.). Ultrasound-guidance is commonly utilized to improve outcomes, limit the need for deep sedation or general anesthesia, and reduce procedural complications. Given the SC and IC approaches are the most common approaches for brachial plexus blocks, the differences between the two have been critically evaluated in the present manuscript. Various studies have demonstrated slight favorability towards the IC approach from the standpoint of complications and safety. Two prospective RCTs found a higher incidence of complications in the SC approach – particularly Horner syndrome. The IC method appears to support a greater block distribution as well. Overall, both SC and IC brachial plexus nerve block approaches are the most effective and safe approaches, particularly under ultrasound-guidance. Given the success of the supraclavicular and infraclavicular blocks, these techniques are an important skill set for the anesthesiologist for intraoperative anesthesia and postoperative analgesia.

Antibiotics for Spinal Cord Stimulation Trials and Implants: A Survey Analysis of Practice Patterns

Background

Spinal cord stimulation (SCS) is an established treatment modality for neuropathic pain. Published guidelines exist to aid physicians in proper antibiotic use during and after spinal cord stimulation trials and implants. In this brief review, we present and analyze the current antibiotic practice patterns of clinicians.

Methods

The study protocol was reviewed and granted an exemption by an Institutional Review Board. The survey queried practice parameters in regards to spinal cord stimulation therapy. The American Society of Regional Anesthesia and Pain Medicine (ASRA) and Society of Interventional Spine (SIS) distributed the survey to their active members by emails with a web link to the survey.

Results

Our results indicate that 82% and 69% of physicians do not utilize nasal swabs for methicillin-sensitive Staphylococcus aureus (MSSA) or methicillin-resistant Staphylococcus aureus (MRSA), respectively, prior to SCS trial and implantation. During trials, 47% providers administer a single dose of antibiotics, 35% administer antibiotics for the duration of the trial, and 17% do not administer antibiotics. During implantation, 44% of physicians administer a single dose during the procedure, 11% administer antibiotics up to 24 hours, 24% administer antibiotics between 3-5 days, 14% administer antibiotics for more than 5 days, and 4% do not administer antibiotics.

Conclusions

Our study suggests a portion of pain physicians do not adhere to the Neuromodulation Appropriateness Consensus Committee (NACC) guidelines in regards to antibiotic administration for SCS trial and implantation. Further analysis and surveys would allow insight into common practices. More information and education would be beneficial to optimize peri-procedure antibiotic use to reduce infection risk and decrease antimicrobial resistance.

Postoperative Pain Management: Efficacy of Caudal Tramadol in Pediatric Lower Abdominal Surgery: A Randomized Clinical Study

BACKGROUND

One of the methods of pain control after pediatric surgical procedures is regional techniques, including caudal block, despite their limitations.

OBJECTIVES

In this study, the pain score and complications of caudal tramadol were evaluated in pediatrics following lower abdominal surgery.

METHODS

In this study, 46 children aged 3 to 10 years were allocated into two equal groups (R and TR) for performing caudal analgesia after lower abdominal surgery. The injectate contained 0.2% ropivacaine 1 mL/kg in the R group (control group) and tramadol (2 mg/kg) and ropivacaine in the TR group. The pain score, duration of pain relief, amount of paracetamol consumption, hemodynamic alterations, and possible complications at specific times (1, 2, and 6 hours) were evaluated in both groups.

RESULTS

No considerable difference was observed in the pain score between the groups in the first and second hours (P > 0.05). However, in the sixth hour, the TR group had a significantly lower pain score than the R group (P < 0.05). Compared to the R group, the TR group had a longer period of analgesia and lower consumption of analgesic drugs (P < 0.05). Heart rate and blood pressure differences were not significant between the two groups (P > 0.05). Similarly, the duration of operation and recovery time were not remarkably different between the two groups (P > 0.05). Complications had no apparent differences between these two groups, as well (P > 0.05).

CONCLUSIONS

In this study, the addition of tramadol to caudal ropivacaine in pediatric lower abdominal surgery promoted pain relief without complications.