Mechanisms of actions of opioids and non-steroidal anti-inflammatory drugs

Nanotechnology-Enhanced Naloxone and Alternative Treatments for Opioid Addiction

Opioids are commonly prescribed to address intense, ongoing pain associated with cancer, as well as long-lasting noncancer-related pain when alternative methods have proven ineffective. Individuals who exhibit both chronic pain and misuse of opioids face a significant danger of experiencing adverse health outcomes and the potential loss of life related to opioid use. Thus, there is a current movement to prescribe naloxone to those considered high-risk for opioid overdose. Naloxone has been explored as an antidote to reverse acute respiratory depression. Conversely, naloxone can give rise to other problems, including hypertension and cardiac arrhythmias. Thus, the importance of nanotechnology-enabled drug delivery strategies and their role in mitigating naloxone side-effects are significant. In this review, we explore the latest advancements in nanotechnology-enabled naloxone and alternative methods for addressing the opioid crisis through the utilization of non-opioid natural alternatives for chronic pain management.

Pharmacological effects of bioactive agents in earthworm extract: A comprehensive review

This review compiles information from the literature on the chemical composition, pharmacological effects, and molecular mechanisms of earthworm extract (EE) and suggests possibilities for clinical translation of EE. We also consider future trends and concerns in this domain. We summarize the bioactive components of EE, including G-90, lysenin, lumbrokinase, antimicrobial peptides, earthworm serine protease (ESP), and polyphenols, and detail the antitumor, antithrombotic, antiviral, antibacterial, anti-inflammatory, analgesic, antioxidant, wound-healing, antifibrotic, and hypoglycemic activities and mechanisms of action of EE based on existing in vitro and in vivo studies. We further propose the potential of EE for clinical translation in anticancer and lipid-modifying therapies, and its promise as source of a novel agent for wound healing and resistance to antibiotic tolerance. The earthworm enzyme lumbrokinase embodies highly effective anticoagulant and thrombolytic properties and has the advantage of not causing bleeding phenomena due to hyperfibrinolysis. Its antifibrotic properties can reduce the excessive accumulation of extracellular matrix. The glycolipoprotein extract G-90 can effectively scavenge reactive oxygen groups and protect cellular tissues from oxidative damage. Earthworms have evolved a well-developed defense mechanism to fight against microbial infections, and the bioactive agents in EE have shown good antibacterial, fungal, and viral properties in in vitro and in vivo experiments and can alleviate inflammatory responses caused by infections, effectively reducing pain. Recent studies have also highlighted the role of EE in lowering blood glucose. EE shows high medicinal value and is expected to be a source of many bioactive compounds.

The impact of preoperative benzodiazepine use on postoperative opioid use in total shoulder arthroplasty

BACKGROUND

As the rate of total shoulder arthroplasty (TSA) and preoperative benzodiazepine use rise, there is an increased need to understand the impact of preoperative benzodiazepine use on postoperative opioid consumption following TSA, especially amid the current opioid epidemic. The relationship between preoperative benzodiazepine use and chronic opioid use postoperatively has been well described following other orthopedic procedures; however, the impact on patients undergoing TSA remains unclear. This study aims to identify the impact of preoperative benzodiazepine use on opioid use following TSA.

METHODS

A retrospective chart review of 4488 patients undergoing primary TSA (Current Procedural Terminology code 23472) at a single institution from 2014 to 2022 was performed. Patient demographics, surgical variables, comorbidities, Distressed Communities Index (DCI), and clinical outcomes, including readmission and revision, were collected. The Charlson Comorbidity Index (CCI) was used to assess preoperative health status. Opioid use in morphine milligram equivalents (MMEs) and benzodiazepine use were also recorded using the Prescription Drug Monitoring Program Database. Opioid use was collected at 30-, 60-, and 90-day intervals both before and after each patient's date of surgery. Statistical analysis included stepwise logistic regression to identify variables independently affecting benzodiazepine use pre- and postoperatively.

RESULTS

Overall, 16% of patients used benzodiazepines within 90 days before their date of surgery. Of those patients, 46.4% were also using preoperative opioids, compared with just 30.0% of patients who were benzodiazepine-naïve (P < .001). Preoperative benzodiazepine use was also associated with increased pre- and postoperative total opioid use in MMEs and the number of opioid prescriptions across all time points when compared to benzodiazepine-naïve patients (P < .001). Furthermore, 37.4% of preoperative benzodiazepine users went on to prolonged opioid use (filled prescriptions >30 days after surgery) compared to 19.0% of those who were benzodiazepine-naïve (P < .001).

CONCLUSION

This study demonstrates a significant association between preoperative benzodiazepine use and increased and prolonged opioid use following TSA. Further exploration of risk factors contributing to preoperative benzodiazepine use may help to reduce overall opioid use in patients undergoing TSA.

The temporal relationship between antibiotic and opioid prescription on the risk of developing an opioid use disorder: A national database study

Background: Previously, we discovered that subjects co-prescribed both antibiotics and opioids on the same day in a hospital setting displayed an increased risk of developing an opioid use disorder (OUD) 12 months following hospital discharge. The goal of this study was to examine whether prescribing antibiotics in the inpatient or emergency department setting at various time points before or after an opioid prescription impacted the risk OUD.Methods: A propensity score matched cohort study was conducted to identify subjects (18-65 years old) with no previous history of OUD. Two cohorts were defined: subjects who were prescribed antibiotics 0-1, 2-4, 5-7, 8-10, 11-12 months before or after the date of an opioid prescription while in the emergency department or inpatient setting, from the years 2010-2019. The diagnosis of an Opioid Related Disorder (F11.10-F11.20) 12 months following discharge from the emergency department or inpatient unit was then observed.Results: Primary analysis showed that subjects prescribed an antibiotic 0-1 month or 8-10 months before an opioid prescription showed a modest risk of developing an OUD 12 months following an opioid prescription (0.04% and 0.20%, respectively). Similarly, subjects prescribed an antibiotic 0-1 month, 5-7 months, or 8-10 months after an opioid prescription displayed a modest risk of developing OUD 12 months after an opioid prescription (0.02% risk, 0.14% risk, and 0.16% risk, respectively).Conclusions: These findings suggest that there is little to no effect on the risk of developing OUD when antibiotics are prescribed at various time points before or after opioid prescription.

Perioperative Pain Management for Distal Radius Fractures

Distal radius fractures have a high incidence among both young and elderly patients, and in many instances require operative intervention. When operative intervention is employed, adequate pain management is essential to decrease postoperative complications, such as chronic pain and disability, while minimizing the risk of prolonged opioid use and dependence. Strategies to optimize pain management include regional anesthesia, preoperative dosing of medication, multimodal regimens, long-acting selective opioids at the time of surgery, corticosteroids, and non-pharmacologic therapies.

Involvement of the Opioidergic Mechanism in the Analgesic Potential of a Novel Indazolone Derivative: Efficacy in the Management of Pain, Neuropathy, and Inflammation Using In Vivo and In Silico Approaches

Indazolones possess interesting pharmacological activities. The search for indazole and indazolone-containing nuclei as drugs is an important research area of medicinal chemistry. The current work aims to evaluate a novel indazolone derivative against in vivo and in silico targets of pain, neuropathy, and inflammation. An indazolone derivative (ID) was synthesized and characterized using advanced spectroscopic techniques. Well-established animal models of abdominal constriction, hot plate, tail immersion, carrageenan paw edema, and Brewer's yeast-induced pyrexia were employed for evaluating the potential of the ID at different doses (20-60 mg kg^-1). Nonselective GABA antagonists, opioid antagonist naloxone (NLX) and pentylenetetrazole (PTZ), were employed to assess the potential role of GABAergic and opioidergic processes. The antineuropathic potential of the drug was evaluated using a vincristine-induced neuropathic pain model. In silico studies were performed to assess any possible interactions of the ID with pain target sites like cyclooxygenases (COX-I/II), GABA_A, and opioid receptors. This study revealed that the selected ID (doses of 20-60 mg kg^-1) efficiently hampered chemically and thermally induced nociceptive responses, producing significant anti-inflammatory and antipyretic effects. These effects produced by the ID were dose-dependent (i.e., 20-60 mg kg^-1 and p range of 0.001-0.01) and significant in comparison to standards (p < 0.001). Antagonistic studies with NLX (1.0 mg kg^-1) and PTZ (15.0 mg kg^-1) revealed the involvement of the opioidergic mechanism rather than the GABAergic mechanism. The ID showed promising anti-static allodynia effects as well. In silico studies revealed preferential binding interactions of the ID with cyclooxygenases (COX-I/II), GABA_A, and opioid receptors. According to the results of the current investigation, the ID may serve in the future as a therapeutic agent for the treatment of pyrexia, chemotherapy-induced neuropathic pain, and nociceptive inflammatory pain.

N-type calcium channel blockers: a new approach towards the treatment of chronic neuropathic pain

Neuropathic pain (NP) remains maltreated for a wide number of patients by the currently available treatments and little research has been done in finding new drugs for treating NP. Ziconotide (PrialtTM) had been developed as the new drug, which belongs to the class of ω-conotoxin MVIIA. It inhibits N-type calcium channels. Ziconotide is under the last phase of the clinical trial, a new non-narcotic drug for the management of NP. Synthetically it has shown the similarities with ω-conotoxin MVIIA, a constituent of poison found in fish hunting snails (Conus magus). Ziconotide acts by selectively blocking neural N-type voltage-sensitized Ca2+ channels (NVSCCs). Certain herbal drugs also have been studied but no clinical result is there and the study is only limited to preclinical data. This review emphasizes the N-type calcium channel inhibitors, and their mechanisms for blocking calcium channels with their remedial prospects for treating chronic NP.

Sex differences among users of NSAIDs and opioids during COVID-19 Pandemic

BACKGROUND

Sex-based inequalities in healthcare have been exposed and amplified during the COVID-19 pandemic. However, few studies have reported sex differences in medication utilization and no studies have examined sex differences in prescribed non-steroidal anti-inflammatory drugs (NSAIDs) and opioids utilization.

AIM

To compare the utilization patterns of prescribed NSAIDs and opioids between males and females in Manitoba, Canada during the COVID-19 pandemic.

METHOD

A cohort of incident and prevalent users of prescribed NSAIDs and opioids was created. Interrupted times series analysis using autoregressive models were used to evaluate the quarterly change in the prevalent and incident users before and after COVID-19 restrictions were applied (first quarter of 2020).

RESULTS

COVID-19 restrictions were associated with a significant decrease in the utilization of prescribed NSAIDs and opioids in all users, followed by a revert to the pre-pandemic trends. Among female prevalent and incident NSAIDs users, there was a significant change in trend after COVID-19 restrictions were introduced (β₃ = 0.087 and 0.078, P = 0.023 and 0.028, respectively). However, there was non-significant change in trend among male prevalent and incident NSAIDs and opioids users during the pandemic.

CONCLUSION

In this study, a significant sharp decline in the use of prescribed NSAIDs and opioids was shown in both sexes at the onset of the pandemic. However, a significant upward trend is observed in female NSAIDs users as restrictions began to be lifted.

Can Anti-inflammatory Drugs used in Plastic Surgery Procedures Increase the Risk of Hematoma?

BACKGROUND

Anti-inflammatory drugs are commonly used to lower inflammation which is linked to a variety of disorders. It acts by inhibiting cyclooxygenase-mediated prostaglandin synthesis at the molecular level. Hematoma is related with the use of anti-inflammatory medications. However, the specific link is still unknown. Thus, the main objective of the study is to find out the association of hematoma with ant-inflammatory drugs.

MATERIAL AND METHODS

The relevant studies were searched in PubMed and screened based on inclusion and exclusion criteria. The quality of full-text studies was assessed using suitable Newcastle-Ottawa Scale. The overall estimate was calculated in terms of odds ratio with 95% confidence interval. The random effect model was used. The qualitative analysis of publication bias was done through funnel plot.

RESULTS

The overall estimate measures [OR 1.01 (0.50, 2.06)] have shown non-significant risk of hematoma with use of anti-inflammatory drugs in plastic surgery as compared to non-anti-inflammatory drugs. The heterogeneity among studies was found to be 34%. The subgroup analysis of individual drugs was not done due to availability of a smaller number of studies.

CONCLUSION

Based on available data, there is no significant risk of hematoma with use of anti-inflammatory drugs in plastic surgery.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Job-Related Performance and Quality of Life Benefits in First Responders Given Access to H-Wave® Device Stimulation: A Retrospective Cohort Study

Current chronic pain treatments primarily target symptoms and are often associated with harmful side-effects and complications, while safer non-invasive electrotherapies like H-Wave® device stimulation (HWDS) have been less explored. The goal of this study is to evaluate first responder-reported effects of HWDS on job-related and quality-of-life measures. This is a retrospective cohort study where first responders were surveyed following voluntary use of HWDS regarding participant experience, frequency of use, job-related performance, and quality-of-life. Responses were analyzed using means comparison tests, while bivariate analysis assessed responses associated with HWDS usage. Overall, 92.9% of first responder HWDS users (26/28) reported a positive experience (p < 0.0001), with 82.1% citing pain reduction (p = 0.0013), while 78.6% indicated it would be beneficial to have future device access (p = 0.0046). Participants using H-Wave® were at least six times more likely to report higher rates of benefit (100% vs. 0%, p = 0.022), including pain reduction (91.3% vs. 8.7%, p = 0.021) and improved range-of-motion (93.3% vs. 69.2%, p = 0.044). Spending more time with family was associated with better job performance following frequent HWDS use (50% vs. 8.3%, p = 0.032). Repetitive first responder H-Wave® use, with minimal side effects and easy utilization, resulted in significant pain reduction, improvements in job performance and range-of-motion, and increased time spent with family, resulting in overall positive experiences and health benefits. Level of Evidence: III.

The Effect of Preoperative Benzodiazepine Usage on Postoperative Opioid Consumption After Hand Surgery: A Multicenter Analysis

Background

Prescription rates of opioids and benzodiazepines have steadily increased in the last decade with the percentage of prescription opioid overdose deaths involving benzodiazepines more than doubling during that time. Orthopaedic surgery is one of the highest-volume opioid prescribing medical specialties, but the effects of benzodiazepine use on orthopaedic surgery patient outcomes are not well understood. The purpose of the study was to utilize the state Prescription Drug Monitoring Program (PDMP) database to investigate if perioperative benzodiazepine use predisposes patients to prolonged opioid use following hand and upper extremity orthopaedic surgery.

Methods

This study was retrospective and conducted at three urban academic institutions. All patients who underwent carpal tunnel release, thumb basal joint arthroplasty, and distal radius fracture open reduction internal fixation performed by 14 board-certified, fellowship-trained orthopaedic hand and upper extremity surgeons between April 2018 and August 2019, were collected via a database query. All opioid and benzodiazepine prescriptions were collected from three months preoperatively to six months postoperatively.

Results

In this study, 634 patients met the inclusion criteria presented to one of the three institutions during the 18-month study period. Patients consisted of 276 carpal tunnel releases, 217 distal radius fracture open reduction internal fixations, and 141 thumb basal joint arthroplasties. Benzodiazepine users were 14.6% more likely to fill an additional opioid prescription (p<0.005) and were 10.8% more likely to experience prolonged three to six-month postoperative opioid use (p<0.005).

Conclusion

This study found that patients who use benzodiazepines are at a higher risk of filling additional opioid prescriptions and prolonged opioid use following hand and upper extremity surgery. Prescribers should take this into account when prescribing opioids after upper extremity orthopaedic surgery.

Impact of maternal substance use on offspring's cardiovascular health

Substance use (SU) during pregnancy is on the rise, posing significant risks to the developing fetus. The adverse impact of maternal alcohol and nicotine use during the perinatal period on offspring health has been well established, including their associations with adverse cardiovascular health in offspring. However, limited studies examine the impact of other well-known SU utilized during pregnancy on offspring's cardiovascular health. This review summarizes the proposed mechanism of action of four commonly utilized substances: cocaine, marijuana, methamphetamine, and opioids, and their cardiovascular impact. Furthermore, we will review the current understanding of the adverse impact of substance use during pregnancy on offspring's cardiovascular system based on existing studies. This review will also highlight possible molecular mechanisms underlying the in-utero adverse programming of offspring's cardiovascular system secondary to SU in pregnancy and address the gaps in current understanding of how SU adversely impacts the developing cardiovascular system of offspring in utero.

Pain management with transdermal drug administration: A review

Pain management is an urgent issue to solve with complex mechanisms. Localized acute pain requires rapid and accurate delivery of drugs with less distribution in the blood circulation while chronic pain requires controlled release of drugs with long drug retention time. The transdermal route, a promising way with high patient compliance was known for painless delivery, long drug retention time, stable blood concentration, easily controlled dosage and release rate as well as the fewer side effects. This review presents transdermal route for pain management according to the different sites of action which drugs aim to reach, and illustrates different analgesic mechanisms, dosage forms, transdermal enhancements and clinical applications. In addition, the review concludes the difference of pain types and presents the future aims of pain management, thereby providing a reference for researches focusing on percutaneous analgesia.

H-Wave® Device Stimulation: A Critical Review

Pain treatments have historically centered on drugs, but an “opioid crisis” has necessitated new standards of care, with a paradigm shift towards multi-modal pain management emphasizing early movement, non-narcotics, and various adjunctive therapies. Electrotherapies remain understudied and most lack high-quality clinical trials, despite a desperate need for effective adjunctive options. A systematic search of human clinical studies on H-Wave^® device stimulation (HWDS) was conducted as well as a comprehensive review of articles articulating possible HWDS mechanisms of action. Studies unrelated to H-Wave were excluded. Data synthesis summarizes outcomes and study designs, categorized as pre-clinical or clinical. Pre-clinical studies demonstrated that HWDS utilizes a biphasic waveform to induce non-fatiguing muscle contractions which positively affect nerve function, blood and lymph flow. Multiple clinical studies have reported significant benefits for diabetic and non-specific neuropathic pain, where function also improved, and pain medication usage substantially dropped. In conclusion, low- to moderate-quality HWDS studies have reported reduced pain, restored functionality, and lower medication use in a variety of disorders, although higher-quality research is needed to verify condition-specific applicability. HWDS has enough reasonable evidence to be considered as an adjunctive component of non-opioid multi-modal pain management, given its excellent safety profile and relative low cost. Level of Evidence: III.

Pharmacology of the Equine Foot: Medical Pain Management for Laminitis

One of the biggest challenges in managing laminitis in horses remains the control of pain. The best analgesic approach is a multimodal approach, including nonsteroidal anti-inflammatory drugs, opioids, and/or constant rate infusions of α-2 agonists, ketamine, and lidocaine. Recent literature indicates that amitriptyline and soluble epoxide hydrolase inhibitor might be beneficial. Clinically oriented studies will be needed if they have a place in laminitis pain management. The systemic pain control can be combined with local techniques such as long-acting local anesthetics or epidural catheterization that allows for administration of potent analgesic therapy with a lower risk of negative side effects.

Antinociceptive effect of the hydroethanolic leaf extract of Calotropis procera (Ait) R. Br. (Apocynaceae): Possible involvement of glutamatergic, cytokines, opioidergic and adenosinergic pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Pain remains real and still a major problem in clinical medicine which requires new agents with improved efficacy for more therapeutic benefits. Plant sources can serve as a basis for the search for some novel drugs hence the analgesic effects of the hydroethanolic extract of Calotropis procera (CPE) which is widespread in Ghana and other tropical areas and used in folkloric medicine for painful and inflammatory conditions was evaluated.

MATERIALS AND METHODS

The analgesic properties of orally administered CPE at doses of 30, 100, and 300 mg/kg were evaluated in thermal (tail immersion), chemical (acetic acid-writhing, formalin-induced paw licking, glutamate-induced nociception) and mechanical (Randall-Selitto) tests for analgesia. The involvement of tumour necrosis factor-alpha (TNF-α), interleukin 1β (IL 1β), bradykinin, and prostaglandin E₂ (PGE₂) on the analgesic effects of CPE were also evaluated in hypernociception assays measuring mechanical pain thresholds.

RESULTS

The latency of tail withdrawal in the tail immersion test was significantly increased (p = 0.0001) while writhing induced by acetic acid was significantly reduced (p < 0.0001) on treatment with CPE (30-300 mg/kg). The extract also significantly inhibited both phase 1 and phase 2 nociceptive states induced by formalin comparable to morphine (p < 0.0001). Furthermore, the extract significantly attenuated hyper-nociception induced by TNF-α (p < 0.0001), interleukin 1β (p = 0.0102), bradykinin (p < 0.0001), and prostaglandin E₂ (p < 0.0001). Additionally, glutamate-induced paw licking was reduced significantly (p < 0.05). The antinociceptive effects exhibited by CPE (100 mg/kg) in the formalin test was reversed by systemic administration of naloxone (2 mg/kg) and theophylline (5 mg/kg) but not glibenclamide (8 mg/kg), granisetron (2 mg/kg), atropine (3 mg/kg), yohimbine (3 mg/kg, p.o.) nor nifedipine (10 mg/kg).

CONCLUSION

Overall, the hydroethanolic leaf extract of Calotropis procera possesses analgesic properties that is mediated possibly through the glutaminergic, opioidergic, and adenosinergic pathways.

The Many Fronts of Battling Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a breathing disorder during sleep secondary to collapsing upper airways that leads to a significant decrease or a complete cessation of airflow despite an effort to breathe. As the name suggests, an obstruction, likely caused by an inherited narrow airway, is the most common cause. But there are less known factors that may contribute to the worsening of OSA. We present a case of very severe OSA contributed by weight gain, opioid use, and anterior cervical discectomy and fusion (ACDF), in addition to a genetically narrow airway. This case highlights the importance of battling OSA on many different fronts. Our patient eventually was able to stop positive airway pressure (PAP) therapy, once the contributing factors were addressed appropriately.

Design, synthesis, and evaluation of novel racecadotril-tetrazole-amino acid derivatives as new potent analgesic agents

Background and purpose:

Although pain is one of the most common symptoms of diseases, it is often mismanaged due to limited access to painkillers and ineffectiveness, unacceptable side effects, or the possibility of abuse. However, an alternative approach to existing analgesics is to indirectly increase endogenous pain relief pathways by neprilysin (an enkephalinase) inhibitors. This enzyme breaks down and inactivates enkephalin, dynorphin, endorphins, and their derivatives.

Experimental approach:

In this project, a new series of racecadotril-tetrazole-amino acid derivatives 15a-l was synthesized and characterized on the basis of IR, ¹H and ¹³C NMR, mass spectrometry, and elemental analysis. The antinociceptive activity of synthesized compounds was assessed by a hot plate, tail-flick, and formalin assays in mice. Docking was used to identify the possible interactions between neprilysin and synthesized compounds. 15a-l was synthesized and characterized on the basis of IR, ¹H and ¹³C NMR, mass spectrometry, and elemental analysis. The antinociceptive activity of synthesized compounds was assessed by a hot plate, tail-flick, and formalin assays in mice. Docking was used to identify the possible interactions between neprilysin and synthesized compounds.

Findings/Results:

Most of the synthesized compounds showed moderate to good analgesic effects in hot plat and tail-flick test in comparison to morphine and racecadotril. Compounds 15l and 15j were the most potent compounds. The synergistic analgesic effect of compounds 15l and 15j with morphine and the antagonistic effect of naloxone on the activity of these compounds confirm that the analgesic effect of compounds 15l and 15j could be mediated through the opioidergic system. The negative and high binding energy of docking simulation of the most potent compounds in the catalytic site of neprilysin was also in good agreement with the inhibitory activity of test compounds.

Conclusion and implications:

Racecadotril-tetrazole-amino acid derivatives, as potential antinociceptive agents, demonstrated moderate to good antinociceptive activities comparable with morphine and higher than racecadotril.

Anti-Inflammatory Potentials of the n-Hexane Fraction of Alstonia boonei Stem Bark in Lipopolysaccharide-Induced Inflammation in Wistar Rats

Background

Inflammation is a protective response of the host to infections and tissue damage and medicinal plants have been used to regulate inflammatory response. The phytochemical contents of the n-hexane fraction of Alstonia boonei and their anti-inflammatory potentials in lipopolysaccharide-induced inflammation were investigated in rat liver.

Materials and Methods

A quantity of 5 mg/kg lipopolysaccharide (LPS) was used to induce inflammation in twenty-five male Wistar rats, grouped (n = 5) and treated as follows: negative control (10 mL/kg saline), positive control (1 mg/kg ibuprofen); 50, 100 and 20 mg/kg of the n-hexane fraction of Alstonia boonei were administered to test groups. In another experiment, twenty rats (n = 5, without LPS) were administered the same doses of the n-hexane fraction of A. boonei and ibuprofen for seven days. At the end of the experiment, animals were sacrificed, serum was obtained from blood and liver mitochondria isolated in a refrigerated centrifuge. Mitochondrial permeability transition (mPT) pore opening and mitochondrial F₀F₁ ATPase (mATPase) were determined spectrophotometrically. Serum interleukins 1β, 6 (IL-1β, IL-6), tumour necrosis factor alpha (TNF-α), C-reactive protein (CRP) and creatine kinase (CK), gamma glutamyl transferase (GGT), aspartate and alanine aminotransferases (AST and ALT,) of the animals in which inflammation was induced using LPS but treated with graded doses of n-hexane fraction of A. boonei were determined using the ELISA technique. The phytochemical contents of the n-hexane fraction of A. boonei were determined using ultra performance liquid chromatography-tandem mass spectrometer (UHPLC-MS).

Results

Calcium induced mPT in 8 fold and LPS induced mPT 14 fold in the negative control while the n-hexane fraction reversed mPT in the treated groups (50, 100 and 200 mg/kg) to 2, 4, 4 folds, respectively. LPS treatment of the negative group enhanced F₀F₁ mATPase activity, increased CRP, TNF-α, IL-1β, IL-6 levels as well as CK, AST, ALT and GGT activities. These values were significantly reduced by 100 and 200 mg/kg of the n-hexane fraction. UHPLC-MS analysis of the fraction revealed the presence of terpenoids, phenolics and sphingolipids.

Conclusion

These results showed that bioactive phytochemicals present in the n-hexane fraction of A. boonei were not toxic, have an anti-inflammatory effect and could be used for the treatment of inflammatory diseases.

Efficacy and Safety of Medicines Targeting Neurotrophic Factors in the Management of Low Back Pain: Protocol for a Systematic Review and Meta-analysis

BACKGROUND

Low back pain (LBP) is the leading cause of years lived with disability worldwide. Most people with LBP receive the diagnosis of nonspecific LBP or sciatica. Medications are commonly prescribed but have limited analgesic effects and are associated with adverse events. A novel treatment approach is to target neurotrophins such as nerve growth factor (NGF) to reduce pain intensity. NGF inhibitors have been tested in some randomized controlled trials (RCTs) in recent years, showing promise for the treatment of chronic LBP; however, their efficacy and safety need to be evaluated to guide regulatory actions.

OBJECTIVE

The aim of this study is to evaluate the efficacy and safety of medicines targeting neurotrophins in patients with LBP and sciatica.

METHODS

In this systematic review, we will include published and unpublished records of parallel RCTs and the first phase of crossover RCTs that compare the effects of medicines targeting neurotrophins with any control group. We will search the CENTRAL, MEDLINE, Embase, CINAHL, ClinicalTrials.gov, EU Clinical Trials Register, and WHO International Clinical Registry Platform databases from inception. Pairs of authors will independently screen the records for eligibility, and we will independently extract data in duplicate. We will conduct a quantitative synthesis (meta-analysis) with the studies that report sufficient data and compare the medicines of interest versus placebo. We will use random-effects models and calculate estimates of effects and heterogeneity for each outcome. We will assess the risk of bias for each study using the Cochrane Collaboration tool, and form judgments of confidence in the evidence according to GRADE recommendations. We will use the PRISMA statement to report the findings. We plan to conduct subgroup analyses by condition, type of medication, and time point. We will also assess the impact of a potential new trial on an existing meta-analysis. Data from studies that meet inclusion criteria but cannot be included in the meta-analysis will be reported narratively.

RESULTS

The protocol was registered on the Open Science Framework on May 19, 2020. As of December 2020, we have identified 1932 records.

CONCLUSIONS

This systematic review and meta-analysis will assess the evidence for the efficacy and safety of NGF inhibitors for pain in patients with nonspecific LBP and sciatica. The inclusion of new studies and unpublished data may improve the precision of the effect estimates and guide regulatory actions of the medications for LBP and sciatica.

TRIAL REGISTRATION

Open Science Framework; https://osf.io/b8adn/.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/22905.

Anti-inflammatory and anti-hyperalgesic effects of milnacipran in inflamed rats: involvement of myeloperoxidase activity, cytokines and oxidative/nitrosative stress

BACKGROUND

Many injuries cause pain and inflammation, which are one of the major challenges for physicians. In this study, the analgesic and the anti-inflammatory effects of milnacipran were investigated on carrageenan-induced nociception and inflammation in male rats.

METHODS

Pain and inflammation were induced by injection of λ-carrageenan (1% v/v) into the hind paw. Indomethacin (10 mg/kg: ip) or milnacipran (10, 20 and 40 mg/kg: ip) were administered 30 min before carrageenan. Analgesia and inflammation were measured by hot plate and plethysmometer. Finally, lipid peroxidation, tumor necrosis factor alpha (TNF-α), Interleukin 1 beta (IL-1β), Interleukin 6 (IL-6), myeloperoxidase (MPO) activity, nitric oxide (NO) and total antioxidant capacity (TAC) status evaluated in the hind paw tissue.

RESULTS

The results showed that carrageenan caused hyperalgesia and inflammation in the hind paw tissue. Milnacipran (20 and 40 mg/kg) significantly and dose-dependently attenuated (65 ± 3.2%; p ≤0.01 and 42 ± 6.2%; p ≤ 0.001, respectively) carrageenan-induced inflammation and significantly increased (p ≤ 0.001) nociception threshold. Also, milnacipran (20 and 40 mg/kg) significantly suppressed levels of malondialdehyde (MDA), NO (p ≤ 0.05), MPO activity, TNF-α, IL-1β and IL-6 (p ≤ 0.001) following carrageenan injection. Additionally, milnacipran (10, 20 and 40 mg/kg) significantly augmented (p ≤ 0.05) TAC status following carrageenan in the hind paw tissue.

CONCLUSION

In the present study, milnacipran showed anti-nociceptive and anti-inflammatory effects on carrageenan-induced hyperalgesia and inflammation in a dose-dependent manner. Milnacipran reduced inflammatory edema and increased the paw withdrawal threshold probably through suppression of MDA, NO, TNF-α, IL-1β, IL-6 and MPO activity, and increase of TAC status in the hind paw tissue. Therefore, milnacipran holds important potential as an anti-inflammatory and anti-nociceptive drug. Although, further clinical trials to confirm this issue, is required.

Renal impairment and analgesia: From effectiveness to adverse effects

Kidney pain is one of the clinically significant features of renal dysfunction. Mild to severe pain is seen in the lower back area. Painkillers are mostly recommended in these cases to relieve the symptom. Yet, several analgesics are associated with side effects that can worsen the state of the disease. This review is based on the studies conducted in these aspects analgesics used to treat kidney pain and their effectiveness, renal consequences of postoperative analgesia, and pharmacogenetics of these palliatives are briefly summarized in this paper.

Contribution of Nrf2 Modulation to the Mechanism of Action of Analgesic and Anti-inflammatory Drugs in Pre-clinical and Clinical Stages

Despite the progress that has occurred in recent years in the development of therapies to treat painful and inflammatory diseases, there is still a need for effective and potent analgesics and anti-inflammatory drugs. It has long been known that several types of antioxidants also possess analgesic and anti-inflammatory properties, indicating a strong relationship between inflammation and oxidative stress. Understanding the underlying mechanisms of action of anti-inflammatory and analgesic drugs, as well as essential targets in disease physiopathology, is essential to the development of novel therapeutic strategies. The Nuclear factor-2 erythroid related factor-2 (Nrf2) is a transcription factor that regulates cellular redox status through endogenous antioxidant systems with simultaneous anti-inflammatory activity. This review summarizes the molecular mechanisms and pharmacological actions screened that link analgesic, anti-inflammatory, natural products, and other therapies to Nrf2 as a regulatory system based on emerging evidences from experimental disease models and new clinical trial data.

Efficacy of thoracic paravertebral block versus systemic analgesia for postoperative thoracotomy pain: a systematic review protocol

REVIEW QUESTION/OBJECTIVE

The objective of the systematic review is to synthesize the best available evidence on the effectiveness of thoracic paravertebral block compared with the use of systemic analgesia on postoperative pain in patients who have undergone a thoracotomy procedure.

Possible mechanisms involved in the anti-nociceptive effects of hydro-ethanolic leaf extract of Ziziphus abyssinica

CONTEXT

Various parts of Ziziphus abyssinica Hochst ex. A. Rich (Rhamnaceae) have been used in Ghanaian and African traditional medicine as an analgesic. However, there are little scientific data to support the anti-nociceptive effects of the hydro-ethanolic leaf extract of Ziziphus abyssinica (EthE) as well as the possible mechanisms involved in its anti-nociceptive effects.

PURPOSE

To predict possible nociceptive pathways involved in the anti-nociceptive effects of EthE.

MATERIALS AND METHODS

The effect of EthE (30, 100 and 300 mg/kg) on intraplantar injection of pain mediators such as interleukin-1β, tumour necrosis factor-α, prostaglandin E₂ and bradykinin was evaluated in male Sprague Dawley rats using Randall-Selitto test for 5 h. The effect of specific antagonists to the opioidergic, adenosinergic, ATP-sensitive K⁺ channels, nitric oxide, serotonergic, muscarinic, adrenergic and voltage-gated calcium channel on the anti-nociceptive effect of EthE (100 mg/kg) was evaluated using the formalin test in male imprinting control region (ICR) mice for 1 h.

RESULTS

Pretreatment of the rats with EthE significantly reversed the hypernociception induced by intraplantar injection of TNF-α (F_4,120 = 10.86, p < 0.0001), IL-1β (F_4,120 = 14.71, p < 0.0001), bradykinin (F_4,80 = 12.52, p < 0.0001) and prostaglandin E₂ (F_5,144 = 6.165, p = 0.0001). The anti-nociceptive effect exhibited by EthE in the formalin test was reversed by systemic administration of N^G-l-nitro-arginine methyl ester, naloxone, theophylline and glibenclamide.

CONCLUSIONS

EthE inhibits hypernociception induced by TNF-α, IL-1β, bradykinin and prostaglandin E₂. EthE exhibited anti-nociceptive effects possibly mediated through opioidergic, adenosinergic, ATP-sensitive potassium channels and nitric oxide cyclic GMP pathways.

Clinical Considerations for the Use Lower Extremity Arthroplasty in the Elderly

There is an increase in the aging population that has led to a surge of reported cases of osteoarthritis and a greater demand for lower extremity arthroplasty. This article aims to review the current treatment options and expectations when considering lower extremity arthroplasty in the elderly patient with an emphasis on the following subjects: (1) updated clinical guidelines for the management of osteoarthritis in the lower extremity, (2) comorbidities and risk factors in the surgical patient, (3) preoperative evaluation and optimization of the surgical patient, (4) surgical approach and implant selection, and (5) rehabilitation and life after lower extremity arthroplasty.

Developing drugs in cancer-related bone pain

INTRODUCTION

Cancer-related bone pain is a frequent and important key problem for metastatic patients that may reduce quality of life, with related limitations in daily activities and morbidity. Often traditional approach to pain may fail given the complex pathophysiology of this phenomenon.

METHODS

The aim of this review is to describe promising therapies for cancer-related bone pain, from the pathophysiology to the clinical trials currently ongoing. Moreover, any new evidence for better approach to cancer-related bone pain with the traditional drugs is also considered.

CONCLUSIONS

In clinical practice opioids remain the most important pharmacologic treatment for severe pain related to bone cancer. Regard developing drugs, anti-NGF and anti-TrkA are the most investigated new drug in this setting, but a future role in clinical practice is still uncertain.

SoluMatrix® Diclofenac: Sustained Opioid-Sparing Effects in a Phase 3 Study in Patients with Postoperative Pain

OBJECTIVES

To evaluate opioid rescue medication usage and the opioid-sparing effect of low-dose SoluMatrix^® diclofenac developed using SoluMatrix Fine Particle Technology™ in a phase 3 study in patients experiencing pain following bunionectomy surgery.

DESIGN

Multicenter, randomized, double-blind, parallel-group study (NCT01462435).

SETTING

Four clinical research centers in the United States.

SUBJECTS

Four hundred twenty-eight patients aged 18 to 65 years who experienced moderate-to-severe pain following bunionectomy surgery.

METHODS

Patients were randomized to receive low-dose SoluMatrix diclofenac 35 mg or 18 mg capsules three times daily (35-mg group or 18-mg group), celecoxib 400 mg loading dose followed by 200-mg capsules twice daily (celecoxib 200-mg group), or placebo capsules postsurgery. Patients were permitted to receive opioid-containing rescue medication as needed.

RESULTS

Significantly fewer patients who received SoluMatrix diclofenac 35 mg or 18 mg or celecoxib required rescue medication during 0-24 h and >24-48 h postsurgery compared with placebo. Patients in the SoluMatrix diclofenac 35 mg or 18 mg groups or in the celecoxib group used fewer mean rescue medication tablets over 0-24 h and >24-48 h compared with placebo-treated patients. Patients in the SoluMatrix diclofenac 35 mg and 18 mg groups and in the celecoxib group also required rescue medication at later times and at slower rates compared with placebo-treated patients. No serious adverse effects occurred in patients receiving SoluMatrix diclofenac.

CONCLUSIONS

SoluMatrix diclofenac at two dosage strengths demonstrated an opioid-sparing effect postoperatively in this phase 3 study.

SUMMARY

The opioid-sparing effect following low-dose SoluMatrix diclofenac (35 mg or 18 mg three times daily) administration was evaluated in patients experiencing pain following bunionectomy. Significantly fewer patients receiving SoluMatrix diclofenac or celecoxib (400 mg loading, 200 mg twice daily) required rescue medication during 0-24 h and >24-48 h following bunionectomy compared with placebo. No serious adverse events were reported among patients who received SoluMatrix diclofenac. SoluMatrix diclofenac may reduce opioid usage in the postoperative setting in patients with acute pain.

Analgesic Effects of Danggui-Shaoyao-San on Various "Phenotypes" of Nociception and Inflammation in a Formalin Pain Model

Danggui-Shaoyao-San (DSS) is a traditional Chinese medicine, which has long been used for pain treatment and has been demonstrated to possess anti-oxidative, cognitive enhancement, and anti-depressant effects. In the present study, the effects of aqueous extracts of DSS on spontaneous pain behaviors and long-term hyperalgesia were examined to investigate the anti-nociceptive effects and underlying mechanisms. Single pretreatment of DSS dose-dependently reduced spontaneous flinches/licking time in the second, rather than the first, phase after subcutaneous injection of 5 % formalin into one hindpaw, in doses of 2.4 and 9.6 g/kg. DSS also dose-dependently inhibited FOS and cyclooxygenase-2 (COX-2) expression in both superficial and deep layers within the spinal dorsal horn. Further, DSS reduced hypoalgesia in the injected paw from 1 to 3 days and produced anti-hyperalgesic actions in both the injected paw after 3 days and non-injected paw. These data suggest involvement of enhancement of descending pain inhibition by suppression of 5-HTT levels in the spinal dorsal horn and reduction of peripheral long-term inflammation, including paw edema and ulcers. These findings suggest that DSS may be a useful therapeutic agent for short- and long-term inflammation induced pain, through both anti-inflammatory and suppression of central sensitization mechanisms.

Pain and the thermally injured patient-a review of current therapies

Thermally injured patients experience tremendous pain from the moment of injury to months or years after their discharge from the hospital. Pain is therefore a critical component of proper management of burns. Although the importance of pain is well recognized, it is often undertreated. Acute uncontrolled pain has been shown to increase the incidence of mental health disorders and increase the incidence of suicide after discharge. Long-term poor pain control leads to an increase in the incidence of persistent pain. Most burn centers have used opioids as the mainstay analgesic, but recently, the significant side effects of opioids have led to the implementation of new and combined therapeutics. Pharmacological agents such as gabapentin, clonidine, dexmedetomidine, and ketamine have all been suggested as adjuncts to opioids in the treatment of burn pain. Nonpharmacological therapies such as hypnosis, virtual reality devices, and behavioral therapy are also essential adjuncts to current medications. This review aims at identifying the currently available pharmacological and nonpharmacological options for optimal pain management in the adult burn population.

Risks associated with drug treatments for kidney stones

INTRODUCTION

Renal stones are one of the most painful medical conditions patients experience. For many they are also a recurrent problem. Fortunately, there are a number of drug therapies available to treat symptoms as well as prevent future stone formation.

AREAS COVERED

Herein, we review the most common drugs used in the treatment of renal stones, explaining the mechanism of action and potential side effects. Search of the Medline databases and relevant textbooks was conducted to obtain the relevant information. Further details were sourced from drug prescribing manuals. Recent studies of drug effectiveness are included as appropriate.

EXPERT OPINION

Recent controversies include medical expulsive therapy trials and complex role of urinary citrate in stone disease. Future directions in research will involve new medical therapies for stone prevention, for example new drugs for hyperoxaluria.

Effects of opium addiction on level of sensory block in spinal anesthesia with bupivacaine for lower abdomen and limb surgery: a case-control study

BACKGROUND

In clinical practice, the level of sensory block in spinal anesthesia in opium abusers is lower than that in non-abusers because of adaptive changes caused by opium use.

OBJECTIVES

The aim of this study was to investigate the level of sensory block resulting from the intrathecal administration of 0.5% bupivacaine in opium abuser patients undergoing lower extremity and lower abdominal surgeries.

PATIENTS AND METHODS

A total of 100 patients who were candidates of elective lower extremity orthopedic and lower abdominal surgeries were recruited and assigned to two groups based on their history of opium addiction (Case or control). Both groups underwent the same anesthesia procedure and pinprick test was used to assess the level of anesthesia.

RESULTS

No statistically significant difference was observed between groups regarding age, duration of the surgery, and type of surgery. The frequency of addiction was higher in males than in females. The level of sensory block at three minutes was significantly lower in the opium abuser group (P = 0.006). The mean time to achieve T10 sensory block was 10.33 ± 5.79 minutes in the opium abusers and 6.89 ± 3.88 minutes in the controls (P = 0.001). The level of the highest sensory block was lower in the opium abuser group (P = 0.002).

CONCLUSIONS

The findings of this study suggested that after induction of spinal anesthesia with intrathecal administration of bupivacaine, chronic opium abusers would have a lower level of sensory block in comparison with patients without a history of opium abuse.

Effectiveness of local anesthesia with lidocaine in chronic opium abusers

CONTEXT

It had been demonstrated that chronic opium abusers have lower pain thresholds compared with than non-abusers.

AIMS

This study aimed to compare the required dose of lidocaine, a common local anesthetic drug, with regard to the onset of anesthesia in opium abusers with that in non-abusers undergoing similar suturing of minor hand lacerations.

MATERIALS AND METHODS

In this study, 109 opium abusers and 91 non-abusers underwent similar suturing for hand lacerations known as digital block. We explained the patients that their case records would remain confidential and admitting to any history of opioid abuse could assist in alleviating any pain associated with the procedure.

RESULTS

There was no statistically significant difference between the two groups with regard to age, gender, and cause of injury (P > 0.05). We found a significantly longer duration of onset of analgesia in nonopioid abusers (5.42 ± 1.93 min) than that in abusers (10.30 ± 1.79 min) (P < 0.001). In addition, the lidocaine dose administered to abusers (6.67 ± 1.21 ml) was higher (4.07 ± 1.26) as well as statistically significant (P < 0.001) than that in non-abusers.

CONCLUSION

The findings from this study suggest a longer duration of onset of anesthesia and requirement of a higher lidocaine dose in opium abusers compared with nonopioid abuser. Moreover, chronic opium abusers (4-5 years) experienced significantly higher time of onset of anesthesia compared with nonchronic abusers. This outcome may be useful in selecting a more suitable local anesthetic protocol in such patients.

Comparison of the pattern, efficacy, and tolerability of self-medicated drugs in primary dysmenorrhea: a questionnaire based survey

Objective:

To compare the pattern, efficacy, and tolerability of self-medicated drugs and to assess the adequacy of their dose in primary dysmenorrhea (PD).

Materials and Methods:

A survey using a self-developed, validated, objective, and structured questionnaire as a tool was conducted among subjects with PD. Statistical analysis was carried out using Chi-square test and ANOVA with post-hoc Tuckey's test.

Results:

Out of 641 respondents, 42% were self-medicated. The pattern of drugs used was: Dicyclomine, an unknown drug, mefenamic acid, mefenamic acid + dicyclomine, and metamizole by 35%, 29%, 26%, 9%, and 1% of respondents, respectively. Mefenamic acid + dicyclomine, the combination was the most efficacious in comparison to other drugs in moderate to severe dysmenorrhea. There was better tolerability with mefenamic acid + dicyclomine group compared to other drugs. Sub-therapeutic doses were used by 86% of self-medicating respondents.

Conclusions:

The prevailing self-medication practices were inappropriate in a substantial proportion of women with inadequate knowledge regarding appropriate drug choice, therapeutic doses, and their associated side effects.

Synergistic analgesia of duloxetine and celecoxib in the mouse formalin test: a combination analysis

Duloxetine, a serotonin and noradrenaline reuptake inhibitor, and celecoxib, a non-steroidal anti-inflammatory drug, are commonly used analgesics for persistent pain, however with moderate gastrointestinal side effects or analgesia tolerance. One promising analgesic strategy is to give a combined prescription, allowing the maximal or equal efficacy with fewer side effects. In the current study, the efficacy and side effects of combined administration of duloxetine and celecoxib were tested in the mouse formalin pain model. The subcutaneous (s.c.) injection of formalin into the left hindpaw induced significant somatic and emotional pain evaluated by the biphasic spontaneous flinching of the injected hindpaw and interphase ultrasonic vocalizations (USVs) during the 1 h after formalin injection, respectively. Pretreatment with intraperitoneal (i.p.) injection of duloxetine or celecoxib at 1 h before formalin injection induced the dose-dependent inhibition on the second but not first phase pain responses. Combined administration of duloxetine and celecoxib showed significant analgesia for the second phase pain responses. Combination analgesia on the first phase was observed only with higher dose combination. A statistical difference between the theoretical and experimental ED₅₀ for the second phase pain responses was observed, which indicated synergistic interaction of the two drugs. Concerning the emotional pain responses revealed with USVs, we assumed that the antinociceptive effects were almost completely derived from duloxetine, since celecoxib was ineffective when administered alone or reduced the dosage of duloxetine when given in combination. Based on the above findings, acute concomitant administration of duloxetine and celecoxib showed synergism on the somatic pain behavior but not emotional pain behaviors.

A novel paracetamol 1,000 mg sustained release formulation vs conventional paracetamol 500 mg formulation in patients with fever and pain: a randomized noninferiority trial

OBJECTIVE

To compare the efficacy and safety of newly developed paracetamol 1,000 mg sustained release (SR) tablets (test product) with conventional paracetamol 500 mg tablets (reference product) in patients with fever and pain.

DESIGN

An open label, multicentric, comparative, randomized, noninferiority trial.

METHODOLOGY

Eligible patient, as per predefined inclusion and exclusion criteria, were randomized to receive either one tablet of test product twice daily or one tablet of reference product four times a day for 3 consecutive days. Primary efficacy parameter (an antipyretic activity) was measured through recording changes in body temperature while secondary efficacy parameter (an analgesic activity) was measured by recording changes in visual analog scale (VAS) from the baseline. Safety assessment was done by recording adverse drug reactions occurred during treatment period. Analysis of variance was used for the statistical evaluation of data.

RESULTS

Of 500 randomized patients, 249 were received paracetamol 1,000 mg SR tablets (Group-I), and 247 were received conventional paracetamol 500 mg tablets (Group-II). Group-I reported temperature reduction from 101.35 ± 1.23°F to 98.80 ± 0.72°F while temperature reduction in Group-II was from 101.42 ± 1.33°F to 98.9 ± 0.85°F. Group-I reported reduction in mean VAS was from 6.16 ± 2.37 to 1.44 ± 1.70 in comparison to Group-II from 5.97 ± 2.45 to 1.38 ± 1.78. No significant adverse reactions were observed in either group.

CONCLUSION

Both the formulations of paracetamol were clinically and statically equivalent. Paracetamol 1,000 mg SR formulation is noninferior to conventional paracetamol 500 mg tablets.

The effect of adjuvant midazolam compared with fentanyl on the duration of spinal anesthesia with 0.5% bupivacaine in opium abusers

Background

There are a number of adjuvants to be used for local anesthetics in spinal block. The aim of this study was to demonstrate the possible effect of intrathecal midazolam compared with bupivacaine as adjuvants in spinal anesthesia with bupivacaine in chronic opium abuses.

Methods

In a double blind, randomized clinical trial, 90 opium abuser patients undergoing lower limb orthopedic surgery were selected and randomly assigned into 3 groups (30 cases each). The patients received 15 mg plain bupivacaine, or 15 mg bupivacaine plus 25 mcg fentanyl or 15 mg bupivacaine plus 1 mg midazolam, intrathecally.

Results

The duration of anesthesia was much longer in the bupivacaine-midazolam group than the bupivacaine-fentanyl group; both were longer than the plain bupivacaine group (P < 0.05).

Conclusions

Subarachnoid injection of adjuvant midazolam or fentanyl with plain 0.5% bupivacaine in opium abusers in lower limb orthopedic surgery increases the duration of sensory block. Therefore midazolam is more effective than fentanyl in such cases.