An overview of tramadol and its usage in pain management and future perspective

Neuroprotective effects of granulocyte colony-stimulating factor against tramadol-induced cerebellar neurotoxicity

BACKGROUND

Tramadol (TRM) is a centrally acting synthetic opioid and serotonin/norepinephrine reuptake inhibitor. Despite being a potent painkiller, long-term use can induce permanent neurotoxicity. Granulocyte colony-stimulating factor (G-CSF) is a cytokine that helps to mobilize stem cells and facilitate their integration over injured neurons.

AIM

This work aims to study the histopathological, biochemical, and molecular alterations in the cerebellar cortex induced by TRM in comparison to the postulated protective effect of G-CSF versus TRM withdrawal.

METHODS

32 adult male albino rats were equally divided into four groups: control, TRM, TRM+G-CSF-treated, and TRM withdrawal groups. The TRM group received a daily dose of 80 mg/kg body weight orally via gastric tube for 12 weeks. The TRM+G-CSF-treated group received subcutaneous injections of 100 μg/kg body weight of G-CSF for seven consecutive days, then TRM from the 8th day. The TRM withdrawal group received TRM for 12 weeks; then, the rats were left without TRM administration for a further 12 weeks. The structural, biochemical, and molecular changes of the cerebellum were measured.

RESULTS

The study revealed that TRM not only induced cerebellar atrophy but also triggered microgliosis, neuroinflammation, and apoptotic indicators, all while suppressing autophagy. However, G-CSF and TRM withdrawal reversed these alterations with superiority to G-CSF.

CONCLUSION

The current investigation shows that G-CSF may improve behavioral, neurochemical, immunohistochemical, and molecular metrics in the rat cerebellum after tramadol-induced injury. G-CSF exhibits a superior protective effect compared to tramadol withdrawal. This is achieved through its antioxidant, anti-apoptotic, and autophagic enhancement properties, as well as its ability to reduce cerebellar gliosis.

Determination of tramadol and its metabolite O-desmethyltramadol in vitreous humor. Is it helpful in forensic casework?

In recent years, there has been increasing interest on the use of alternative biological materials in forensic toxicology. Vitreous humor is one of them, which, due to the closed cavity it is contained, has a low degree of contamination and high purity that makes it ideal for use in postmortem specimens. The aim of this study was to investigate the distribution of tramadol and its active metabolite O-desmethyltramadol in vitreous humor and the usefulness of using this alternative biological matrix in tramadol-related forensic cases. For this purpose, a gas chromatography-mass spectrometric method for the determination of the two analytes in blood and vitreous humor samples, which included solid-phase extraction and derivatization using N,O-Bis(trimethylsilyl)trifluoroacetamide with 1% trimethylsilyl chloride, was developed. The method was fully validated according to international guidelines and was applied to blood and vitreous humor samples from 12 forensic cases. Both substances were found to be readily distributed in vitreous humor, since even in cases of very low concentrations of the analytes in blood, their detection was also possible in vitreous humor. In addition, the vitreous humor to blood concentration ratios were calculated for both substances and the mean values were found to be 0.91 for tramadol and 0.94 for O-desmethyltramadol. The results of our study indicate that the information that can be extracted from the analysis of vitreous humor samples is particularly useful during the investigation of tramadol-related cases. Nevertheless, the need for further study of this alternative material to establish therapeutic and toxic limits becomes apparent.

Consensus statement on chronic pain treatment in cancer survivors

In September 2023, the Japan Society of Pain Clinicians (JSPC) issued this consensus statement on chronic pain treatment in cancer survivors. With recent advances in the early diagnosis and treatment of cancer, its prognosis has improved, so prolonged pain in cancer survivors is considered to represent chronic pain and should be addressed. In this statement, we emphasize that not all cancer survivor pain is cancer pain. Pain that is not cancer pain should be managed with analgesics other than opioids and nerve blocks, and pain that persists despite this approach should be treated as non-cancer chronic pain so as to prevent opioid overuse. In addition, cancer survivors at any stage of disease have a potentially life-threatening condition and constantly carry the fear of cancer recurrence. Therefore, even non-cancer pain should not be treated in the same way as general chronic pain, but should be managed with consideration of emotional distress. In the future, we plan to create educational tools for healthcare professionals and to conduct online seminars, both with the goal of providing cancer survivors with appropriate assessment and treatment of chronic pain.

The prevalence of Tramadol abuse and associated factors among Hawassa University students, Hawassa, Ethiopia

INTRODUCTION

Tramadol abuse is a current public health concern in Ethiopia. Drug abuse including that of tramadol is a significant public health issue that causes health, economic, and social problems to individual drug users, their families, the community, and the entire nation. Therefore this study delivers information regarding current tramadol abuse among students of an Ethiopian University.

OBJECTIVE

The aim of this study is to assess the prevalence of tramadol abuse and associated factors among Hawassa university students, February to June 2023.

METHODS AND MATERIALS

A cross-sectional study was performed among 402 randomly selected Hawassa university students. Data was collected from participant through self-administered researcher made questionnaire using kobo toolbox software applications. Data from kobo toolbox were directly exported to and analyzed by using SPSS version 26 software. Binary logistic regression was applied to identify the factors associated with tramadol abuse. In the final model, Adjusted Odds Ratio, and 95% CI was used to measure the strength of association and P-value less than 0.05 considered statistically significant.

RESULT

A total of 402 students were enrolled in this study of which 46 students (11.4%) [95% CI 8.5-14.7] had history of tramadol abuse once in their lifetime with 23.9% of them were active tramadol abuser with some dependence behaviors. The result of multivariate analysis shows that having a friend who use drugs [AOR = 1.691, 95% CI (0.718-3.980), p = 0.041], knowing about tramadol [AOR = 13.766, 95%CI (3.003-63.113), p = 0.001] and having the history of taking tramadol with physicians prescription in their life time [AOR = 7.960, 95%CI (3.603-17.587), P < 0.001] were the significant predictors of tramadol abuse.

CONCLUSION

The life time prevalence of tramadol abuse among university students is high and it demands attention of government and the general public.

Intravenous vs. Oral Dose Comparison of Ibuprofen and Tramadol Combinations-Enantiomers, Metabolite, Linearity, and Sex-Related Effects: A Pharmacokinetics Randomized Clinical Trial

Background/Objectives: Using a combination of analgesics allows for the use of lower doses of each, therefore, lowering risk of side effects. The study aims to estimate the bioavailability (pharmacokinetics of enantiomers and metabolites, as well as linearity and sex-related effects) of fixed doses combinations of Ibuprofen/Tramadol via an intravenous (IV) vs. oral route, and it is interesting to bridge the gap of equipotent doses by different routes. Methods: This was a randomized, open-label, crossover, five-period pharmacokinetics clinical trial, in which a single dose of each formulation [four different strengths of Ibuprofen 400 mg/Tramadol HCl (30, 31.5, 33, 37.5 mg), intravenous; Ibuprofen/Tramadol HCl 400 mg/37.5 mg, granules for oral solution], were administered to healthy volunteers. Enantiomers of Ibuprofen, of Tramadol, and of its main active metabolite O-desmethyl-Tramadol (M1) were measured, and pharmacokinetic parameters (maximal concentration (Cmax) and area under the concentration curve (AUC)) were estimated. Given the exploratory nature of the study, the sample size was small to provide sufficient power for comparisons of differences across all subgroups. The study was registered at Spanish register of clinical trials (REec), EudraCT code: 2017-001303-77. Results: Twelve subjects were recruited. Different patterns of rate and amount of the studied analytes are shown for oral and the several strengths of IV drugs tested. Ibuprofen, with an absolute oral bioavailability of 91%, showed an equivalent AUC of oral and IV administration. Tramadol showed an absolute oral bioavailability of 80%. Conclusions: Intravenous administration of Tramadol produces higher bioavailability (Cmax and AUClast) of the parent drug and lower of M1, than oral route. Dose normalized Cmax and AUClast of Tramadol and M1 were into the bioequivalence interval. Upon our pharmacokinetics study results, the intravenous dose of Tramadol should not be reduced when switching from oral dosing. No significant differences attributable to sex, once corrected by weight, were found.

Tramadol and mental health: A systematic review of case reports describing psychological side-effects

OBJECTIVE

Tramadol is a synthetic opioid widely used in clinical practice to treat moderate to severe pain. While it is considered safer than traditional opioids, growing concerns have emerged regarding its adverse psychological effects. This systematic review examined tramadol-induced psychological side effects, identified risk factors, and evaluated possible underlying mechanisms that might help to guide safer clinical use.

METHODS

A systematic search was conducted in PubMed, Scopus, Web of Science, and Google Scholar using the related keywords of tramadol and psychological effects. This review primarily focused on case reports, which were included if they provided detailed accounts of tramadol-induced mental health side-effects. Two independent reviewers screened the studies, and data was extracted on patient demographics, details of tramadol usage, psychological outcomes, and risk factors. The quality of the case reports was assessed using the Joanna Briggs Institute (JBI) scale.

RESULTS

The review found that tramadol is associated with a range of psychological symptoms, including manic episodes, hypomania, serotonin syndrome, psychosis, and cognitive impairment. Risk factors included age, pre-existing psychiatric conditions, polydrug use, and prolonged tramadol use. Elderly individuals and those with psychiatric histories were particularly vulnerable.

CONCLUSION

Tramadol has the potential to cause serious psychological side effects, prompting cautious prescription, especially in vulnerable populations. Clinicians should closely monitor patients for these adverse effects, and further research is needed to understand the mechanisms involved and to reduce the psychological site-effects resulting from tramadol use.

Lived Experiences of Nonmedical Use of Tramadol Among Urban Slum-Dwelling Youth in Ghana: A Qualitative Study

The world is witnessing a pharmaceutical opioid crisis, and in Africa's version, the nonmedical use of Tramadol is prevalent in vulnerable populations. However, data on the factors promoting nonmedical use of Tramadol in slums is generally lacking. The study explored the factors that promote the nonmedical use of Tramadol among urban slum-dwelling youth in the Asokore Mampong Municipality, Ghana. This qualitative study recruited 20 nonmedical Tramadol users from Asawase and Aboabo in the Asokore Mampong Municipality as participants. Data were gathered through face-to-face, in-depth interviews via the snowball sampling technique. Data were analyzed using themes and direct quotations. The study observed that Tramadol was used in quantities exceeding what is medically acceptable many times daily and in combination with other substances with psychoactive properties. Tramadol use was informed by its efficacy in providing physical (reducing tiredness, pain relief, and sexual enhancement) and psychological (mood enhancement) benefits. Easy accessibility and affordability of Tramadol, coupled with lax measures in checking substance use, contribute to its nonmedical use with other substances. The extent of abuse of Tramadol in the study setting needs urgent attention. Educational programs on substance use, counseling interventions, and effective drug monitoring and surveillance are required to curb the menace.

Abuse and misuse of tramadol in patients with non-oncologic pain in a region of Southern Europe

Background

Tramadol can cause dependence even within the recommended dose range. Its use has increased recently, especially in patients with chronic pain, and although a growing body of literature identifies a non-therapeutic use, patterns of misuse of tramadol is so far limited.

Methods

Two-year observational and cross-sectional study (January 2020 - December 2021) was conducted in 75 community pharmacies from Catalonia. To estimate the potential abuse and misuse of tramadol by patients visiting community pharmacy, and to establish the demographic characteristics of the tramadol users, a validated questionnaire based on the Finch criteria was designed. A total of 251 cases were registered.

Results

Data show that women were more involved (56.6%) and the highest proportion was found in the age interval of 46-65 years (42.6%). The combination of tramadol and paracetamol was reported in 54.6% of the cases and 73.7% corresponded to immediate-release tablets. In 93.6% of the cases, the request was preceded by previous use. Conversely, young men showed a higher non-prescription request for tramadol, reporting acute pain (p < 0.05). These results indicate that there is non-therapeutic use among patients who visit community pharmacies for information on two profiles.

Conclusion

This study shows that being an aged woman and suffering from chronic pain seems to involve a risk of generating dependence on tramadol. Likewise, a suspicion of recreational use of tramadol by young people has also been identified. There is a need to investigate how to manage chronic pain, given its complexity and take into account the risk of misuse that may come with tramadol. The involvement of characteristics such as gender as well as the pharmaceutical form in the development of tramadol misuse also needs to be analysed deeply. It is mandatory to evaluate the criteria for prescribing tramadol and initiatives to improve the knowledge of the health professionals and the population.

Involvement of Receptor Apparatus in the Realization of Antinociceptive Activity of Songorine

The receptor mechanism of the antinociceptive effect of the diterpene alkaloid songorine was investigated in an experiment on mice. Antagonists of peripheral opioid, κ-opioid, and cannabinoid 1 receptors eliminated the analgesic effect of songorine. These findings suggest that these receptors are involved in the antinociceptive action of songorine.

Green and High Throughput HPTLC Method for Simultaneous Estimation of Celecoxib and Tramadol Hydrochloride in their Newly Approved Analgesic Combination and Spiked Plasma with Dichromic Green and Blue Assessments

The FDA "Food and Drug Administration" recently approved a novel co-crystal formulation of Celecoxib (CEX) and Tramadol (TRM) for the treatment of adults suffering from moderate to severe pain in several conditions. This novel combination has advantages over co-administration of the two drugs individually as better patient compliance, synergism and lower therapeutic cost. This work presents the first "High performance Thin Layer Chromatographic" (HPTLC) quantitative analytical technique for CEX and TRM simultaneous assay in bulk, their new dosage form and plasma.The proposed HPTLC assay is based on separation of CEX and TRM on silica gel 60 F254 sheets followed by densitometric scanning at 270 nm. The plates' development was carried out using a mobile phase of ethyl acetate-methanol-ammonia (5:5:0.05, v/v). The two drugs showed linearity of 0.025-1 μg.band-1& for plasma analysis linearity range was 0.2-10 μg.mL-1plasma. The proposed chromatographic technique was validated and showed satisfying validation characteristics of linearity, selectivity, precision and accuracy. In addition, the assay was evaluated by AGREE, AGREEprep, ComplexMoGAPI and BAGI for greenness and blueness to ensure the method's environmental sustainability and its safety for routine quality control assay of this novel combination.

Catalyzing Pharmacogenomic Analysis for Informing Pain Treatment (C-PAIN): A Randomized Trial of Preemptive CYP2D6 Genotyping in Cancer Palliative Care

Background

Cancer patients frequently suffer from pain, often managed with opioids. However, undertreated pain remains a significant concern. Opioid effectiveness varies due to genetic differences in how individuals metabolize some of these medications. While prior research suggests promise in tailoring opioid prescriptions based on CYP2D6 genetic makeup, its application in cancer pain management remains limited. This study investigates the potential benefits of preemptive CYP2D6 genotyping for cancer patients initiating opioid therapy, focusing on codeine, tramadol, and hydrocodone, whose efficacy is demonstrably impacted by CYP2D6 variations.

Methods

This is a randomized, prospective study to evaluate the effects of preemptive pharmacogenomic (PGx) testing on opioid dosing decisions/selections and composite pain score in oncology patients. Patients with metastatic solid tumors for whom near-future opioid therapy is anticipated will be randomized to PGx and control arms, stratified by the presence or absence of bony metastases and history of opioid use. In the PGx arm, patients will be preemptively tested using a panel of pharmacogenomic genetic variants, and providers will receive opioid dosing guidance via an electronic medical record-embedded clinical decision support tool. In the control arm, pain prescribing will occur per standard of care without genotype information.

Planned Outcome

The primary study outcome will be composite pain intensity during the first 45 days after an index opioid prescription for codeine, tramadol, or hydrocodone. Safety will be assessed by comparing opioid-related adverse event rates between the two study arms. Secondary outcomes will include rates of hospitalization/emergency room visits, cumulative morphine equivalents received, and type of first opioid prescribed.

Molecular-Oxygen-Mediated Multicomponent Oxidative Cyclization: Synthesis of Tertiary-Alcohol-Unit-Bearing N-Heterocycles via Transforming C-H to C-OH Bonds

We developed a molecular-oxygen-mediated multicomponent oxidative cyclization strategy to synthesize N-heterocycles containing tertiary alcohol units via the formation of key C-OH bonds and quaternary carbon centers. This formal [3 + 2 + 1] annulation offers a green and sustainable alternative for the de novo C-OH bond formation, using O2 as both the oxidant and oxygen source under metal- and catalyst-free conditions. Notably, continuous [1,5]-hydrogen transfer together with excess alcohols promotes the formation of C-OH-bearing products. Additionally, the generation of quaternary carbon centers inhibits the conversion of C-OH bonds to C═O bonds, thus stabilizing the desired products.

A Gas Chromatography-Mass Spectrometry Method to Determine Tramadol Abuse Using Urine Samples

Background The synthetic opioid tramadol is widely used as a pain reliever. Unlike other opioids, it is used freely worldwide, unaffected by international controls resulting in abuse and accidental intoxication. Analytical methods are necessary to prove tramadol abuse because 30% of the drug is excreted unchanged. Methodology This study describes a sensitive, precise, and accurate gas chromatograph-mass spectrometry (GC-MS) method for tramadol quantification in biological samples using solid-phase extraction (SPE) for sample preparation. Results A total of 747 samples were analyzed for suspected tramadol abuse; 15% of samples were above cut-off with a mean of 341.0 ± 215 ng/mL. No interference from other substances was detected. Calibration was linear over the concentration range of 50-1,000 ng/mL with a correlation coefficient of >0.998. Recovery was 92.5% and precision was ≤5% (range = 2.68-5.58%). Conclusions The effectiveness of the SPE in assessing tramadol abuse was assessed with GC-MS. With good recovery, quick analysis times, simplicity, little matrix effect, and effectiveness, this method is regarded as novel and is capable of identifying abuse.

Prevalence and factors associated with tramadol use among university students in Ghana: a cross-sectional survey

BACKGROUND

There are progressively alarming rates of non-medical use, addiction and possible dependence on tramadol in low-middle-income countries. Tramadol is known to heighten negative consequences on social interactions, physical and cognitive abilities among adolescents, students and youth, particularly those with polysubstance use. However, literature on the use of tramadol in low-middle-income countries, especially among undergraduate university students in Ghana remains inadequate. Thus, this study sought to determine the prevalence and factors associated with tramadol use among undergraduate students in Ghana.

METHODS

An institutional-based cross-sectional study and a quota sampling technique were employed to gather data from January to March 2023 on 600 undergraduate students from the University for Development Studies, Tamale, Ghana and analyzed with SPSS (version 26.0). Multiple logistic regression model was used to identify factors associated with the use of tramadol (p-value ≤ 0.05).

RESULTS

The lifetime prevalence of tramadol use was 17.8%. Among those who used tramadol in their lifetime, 14.95% used tramadol alone whereas 85.05% used at least one substance alongside tramadol. The study recorded more females (67.8%) than males. Students aged 20-24 years (20.5%), those single/never married (18.7%), those renting/living alone (19.7%) and first year students (17.4%) accounted for the majority of groups at high risk of lifetime tramadol use. To improve academic performance was the primary reason for initiating tramadol use. Male sex (adjusted odds ratio [AOR] 2.673; 95% confidence interval [CI] 1.590-4.493; p < 0.0001) and those with lifetime cannabis use (AOR 2.137; 95%CI 1.267-3.604; p = 0.004) were significantly associated with lifetime tramadol use.

CONCLUSIONS

This study revealed that lifetime tramadol use was high. Male sex and those with lifetime cannabis use were significantly related with lifetime tramadol use. The use of tramadol has become a public health threat and is important to limit its incidence and continuous use through extensive school and community health campaigns and strengthening of governmental policies against tramadol and other substance use since they increase the propensity of unwarranted cognitive, physical and social outcomes.

Comparative Bioavailability of a Novel Fixed-dose Combination Etoricoxib and Tramadol

Multimodal analgesia is defined as using several drugs or techniques simultaneously to target different pain pathways or receptors to avoid pain propagation. This study evaluated the pharmacokinetic profile and comparative bioavailability of etoricoxib 90 mg and tramadol 50 mg dosing alone (reference drugs) or in a novel fixed-dose combination (test drug) under fasting conditions in Mexican healthy volunteers. This was a randomized, open-label, 3-way, crossover, single-dose, prospective, and longitudinal study with a 14-day washout period. Eligible subjects were healthy Mexican adult volunteers. The drugs were dosing orally, according to the randomization sequence, after 10 hours of fasting and 4 hours before breakfast with 250 mL of water at room temperature. Serial blood samples were collected before and after dosing, both drugs were quantified using high-performance liquid chromatography coupled with tandem mass spectrometry. Forty-two subjects were enrolled and 38 completed the study (28 men and 14 women, mean age 25.2 years, mean weight 66.6 kg). Test products were considered to have comparative bioavailability if confidence intervals of natural log-transformed for (maximum plasma drug concentration (Cmax), (area under the plasma drug concentration-time curve form 0 up to last sampling time (AUC0-t), and (area under the plasma drug concentration-time curve from 0 up to infinity (AUC0-∞) data were within the range of 80%-125%. Non-serious adverse events were observed. The results demonstrate that the pharmacokinetic profile and bioavailability of the etoricoxib/tramadol fixed-dose combination are comparable to those of the reference products.

Tramadol use in U.S. Adults With Commercial Health Insurance, 2005-2021

INTRODUCTION

Tramadol has been associated with chronic opioid use and emergency room (ER) visits. However, little is known about trends in prescription tramadol use in the U.S.

METHODS

Optum's de-identified Clinformatics® Data Mart Database was used to assess trends in monthly incident and prevalent tramadol use from 2005 to 2021, stratified by sex and age (18-64 vs. ≥65 years). State-specific trends following scheduling of tramadol as Class IV controlled substance in August 2014 were analyzed with random effects regression models. Demographics, comorbidities, initiation setting, dose, and co-dispensing with other opioids and central nervous system (CNS) agents were assessed in people initiating tramadol, stratified by age and initiation year (2005-2010, 2011-2015, 2016-2021). Analyses were performed in 2023 and 2024.

RESULTS

During 2005-2021, the mean percentage using tramadol in a given month was 0.88% of younger females, 0.55% of younger males, 1.97% of older females, and 1.14% of older males; 5,729,652 initiations were identified. Since 2014, estimated relative yearly decrease was 4% (95% CI 3%; 5%) in use and 5% (95% CI 4%; 5%) in initiation, with variation across states. Primary care percentage of tramadol initiations declined from 49.2% in 2005-2010 to 37.2% in 2016-2021. During 2016-2021, co-dispensing with other CNS agents occurred in 37.8% of younger and 32.1% of older adults initiating tramadol.

CONCLUSIONS

Tramadol use was higher in females and older adults, exhibited heterogeneous trends across states, and shifted from primary care to ER and specialist settings over time. Co-dispensing with other CNS agents was common and warrants further monitoring.

Chiral Switches of Tramadol Hydrochloride, a Potential Psychedelic Drug-Past and Future

The chiral opioid analgesic tramadol was patented (1962) as a cis- and trans-racemates mixture. A first chiral switch led to the (±)-cis-(1RS,2RS) racemate, patented and approved as Tramal (1980), preferred over the (+)-cis-(1R,2R)-enantiomer. Consecutive chiral switches of (±)-cis-tramadol to (+)-cis-(1R,2R)-tramadol/salts were patented. This Viewpoint calls for developing (+)-cis-(1R,2R)-tramadol medicines and recognizing tramadol medicines as potential psychedelics to overcome the spreading tramadol crisis.

Advancements in Modern Treatment Approaches for Central Post-Stroke Pain: A Narrative Review

PURPOSE OF REVIEW

Central post-stroke pain (CPSP) poses a multifaceted challenge in medical practice, necessitating a thorough and multidisciplinary approach for its diagnosis and treatment. This review examines current methods for addressing CPSP, highlighting both pharmacological and non-pharmacological therapies. It covers the mechanisms and clinical effectiveness of these treatments in managing CPSP and emphasizes the importance of personalized treatment plans, given the varied causes of CPSP.

RECENT FINDINGS

Recent advancements have illuminated diverse treatment modalities for CPSP. Pharmacotherapy spans from conventional analgesics to anticonvulsants and antidepressants, tailored to mitigate the neuropathic characteristics of CPSP. Non-pharmacological interventions, including physical therapy and psychological strategies, are pivotal in managing CPSP's chronic nature. For cases resistant to standard treatments, advanced interventions such as nerve blocks and surgical procedures like deep brain stimulation (DBS) or motor cortex stimulation (MCS) are considered. Additionally, innovative technologies such as neuromodulation techniques and personalized medicine are emerging as promising avenues to enhance therapeutic outcomes and improve quality of life for individuals grappling with CPSP.

SUMMARY

Modern approaches in managing CPSP require an interdisciplinary and patient-centric approach. Customizing treatment plans to address the specific etiology and symptoms of CPSP is crucial. Pharmacotherapy remains fundamental, encompassing medications such as anticonvulsants and antidepressants tailored to manage neuropathic pain. Integrating non-pharmacological interventions is crucial for providing comprehensive care. Additionally, investigating innovative technologies and personalized medicine presents promising opportunities to enhance treatment results and elevate the quality of life for those suffering from CPSP. Ultimately, an integrated approach that acknowledges the multifaceted nature of CPSP is essential for effective management and patient well-being.

Combined antiallodynic effects of Neurotropin®-tramadol and Neurotropin®-mirogabalin in rats with L5-spinal nerve ligation

We aimed to examine the efficacy of combination therapies of Neurotropin® with tramadol and Neurotropin with mirogabalin for neuropathic pain management. A neuropathic pain model (L5 spinal nerve ligation model: L5-SNL) using male Wistar rats was generated through tight ligation of the left fifth lumbar nerve using silk sutures. Mechanical allodynia was assessed using the 50% paw withdrawal threshold. The combined antiallodynic effects were evaluated using isobolographic analyses. Small intestinal transit was evaluated using the charcoal meal test, and motor coordination using the rota-rod test. Neurotropin (50-200 NU/kg, p.o.), tramadol (7.5-60 mg/kg, p.o.), and mirogabalin (3-30 mg/kg, p.o.) showed a dose-dependent antiallodynic effect in L5-SNL rats. The combined antiallodynic effects of Neurotropin and tramadol were additive or synergistic, whereas those of Neurotropin and mirogabalin were additive. Neurotropin (100-400 NU/kg, p.o.) did not affect the small intestinal transit, whereas tramadol (30-100 mg/kg, p.o.) significantly inhibited it. Neurotropin (100-400 NU/kg, p.o.) did not affect the walking time, whereas mirogabalin (10-100 mg/kg, p.o.) significantly decreased it. Neurotropin dose-dependently ameliorated mechanical allodynia in rats, and combination therapy with Neurotropin-tramadol or Neurotropin-mirogabalin may alleviate neuropathic pain without aggravating the adverse effects of tramadol and mirogabalin.

Assessment of metabolic interaction between curcumin and tramadol using the isolated perfused rat liver

Introduction

The presence of phytochemicals in herbal medicines can lead to herb-drug interactions, altering the levels of these compounds and conventional drugs in the bloodstream by influencing CYP450 activity. Considering curcumin's effect on the CYP enzymes responsible for tramadol metabolism, it is essential to assess the potential interaction between curcumin and tramadol when administered together.

Materials and methods

The pharmacokinetics of tramadol were examined in rats receiving either single or multiple doses of curcumin (80 mg/kg) compared to rats without curcumin treatment. Tramadol liver perfusion was conducted on all rat groups and perfusate samples were collected at specified intervals. Tramadol and its main metabolite were detected using an HPLC system coupled with a fluorescence detector.

Results

Tramadol concentrations were notably higher in the co-administered group compared to both the control and treatment groups. Conversely, lower concentrations of M1 were observed in the co-administered and treatment groups compared to the control group. The AUC0-60 parameters for tramadol were as follows: 32944.8 ± 1355.5, 22925.7 ± 1650.1, and 36548.0 ± 2808.4 ng⋅min/ml for the control, treatment, and co-administered groups, respectively. Both the co-administered and treatment groups exhibited a lower AUC0-60 of M1 compared to the control group. The lack of significant difference in Cmax and AUC0-60 of M1 between the treatment and co-administered groups suggests that single and multiple doses of curcumin have comparable effects on CYP2D6.

Conclusions

These results indicate a potential for drug interactions when curcumin and tramadol are taken together. Furthermore, the influence of curcumin on tramadol metabolism varied between single and multiple oral administrations of curcumin. Hence, it is vital to highlight this interaction in clinical settings and conduct additional research to fully understand the clinical implications of combining curcumin and tramadol.

Safety and Efficacy of Combined Injection of Pure-μ-Opioid Agonist with Tramadol as an Opioid Induction Agent for Opioid-Naïve Cancer Patients

Background

Tramadol is known to provide synergistic analgesia when used in combination with morphine.

Objectives

The aims of this study were: (1) to introduce an opioid combination therapy using pure-μ-opioid receptor agonist (OPI) + tramadol injections (OPI + tramadol) and (2) to elucidate safety and efficacy of this combination therapy for opioid-naïve cancer pain patients.

Methods

Opioid-naïve patients referred to our palliative care team (in Japan) who were unable to take oral medications and received OPI + tramadol as opioid induction agents were retrospectively investigated on the electric medical chart. OPI + tramadol dosage was adjusted to achieve the patient's pain as Numerical Rating Scale ≤4/10 or Support Team Assessment Schedule-Japanese ≤1. Patients' demography, doses of OPI and tramadol administered, and adverse events were analyzed.

Results

A total of 44 patients were included. The primary organs of malignancy were pancreas (11), stomach (5), lung (4), breast (4), liver (4), and others (13). OPI injections administered were hydromorphone (39), morphine (6), oxycodone (1), and fentanyl (1). The starting doses of OPI (morphine equivalent) and tramadol were 6.05 ± 1.63 and 67.8 ± 13.6 mg/day, respectively, and the final doses of OPI (morphine equivalent) and tramadol were 8.14 ± 3.85 and 80.0 ± 28.5 mg/day, respectively. Treatment goals were achieved in all patients. There were three patients in whom OPI was switched owing to inadequate analgesia and no new side effects other than those known to occur when OPI or tramadol is administered appeared.

Conclusion

The results suggest that this innovative and unique opioid therapy can be safely and effectively introduced to opioid-naïve cancer patients who are relatively close to the end of life.

A novel tramadol-polycaprolactone implant could palliate heroin conditioned place preference and withdrawal in rats: behavioral and neurochemical study

Drug dependence is a chronic brain disease characterized by craving and recurrent episodes of relapse. Tramadol HCl is a promising agent for withdrawal symptoms management, considering its relatively low abuse potential and safety. Oral administration, however, is not preferred in abstinence maintenance programs. Introducing an implantable, long-lasting formula is suggested to help outpatient abstinence programs achieve higher rates of treatment continuation. Tramadol implants (T350 and T650) were prepared on polycaprolactone polymer ribbons by the wet method. Male Wistar rats were adapted to heroin-conditioned place preference (CPP) at escalating doses (3-30 mg/kg, intraperitoneally, for 14 days). Implants were surgically implanted in the back skin of rats. After 14 days, the CPP score was recorded. Naloxone (1 mg/kg, intraperitoneally) was used to induce withdrawal on day 15, and symptoms were scored. Elevated plus maze and open field tests were performed for anxiety-related symptoms. Striata were analyzed for neurochemical changes reflected in dopamine, 3,4-dihydroxyphenyl acetic acid, gamma-aminobutyric acid, and serotonin levels. Brain oxidative changes including glutathione and lipid peroxides were assessed. The tramadol implants (T350 and T650) reduced heroin CPP and limited naloxone-induced withdrawal symptoms. The striata showed increased levels of 3,4-dihydroxyphenyl acetic acid, and serotonin and decreased levels of gamma-aminobutyric acid and dopamine after heroin withdrawal induction, which were reversed after implanting T350 and T650. Implants restore the brain oxidative state. Nonsignificant low naloxone-induced withdrawal score after the implant was used in naive subjects indicating low abuse potential of the implants. The presented tramadol implants were effective at diminishing heroin CPP and withdrawal in rats, suggesting further investigations for application in the management of opioid withdrawal.

Does Tramadol Exposure Have Unfavorable Effects on Hippocampus? A Review Study

Background

Tramadol, one of the most common opioid pain relievers, acts upon the µ-receptor in the central nervous system (CNS) to alleviate pain associated with various situations like postoperative pain, arthritis, and muscular pain. Additionally, it has been utilized to address depression and anxiety disorders. Extensive research has shown that tramadol can potentially inflict irreversible harm on different regions of the CNS, including the cerebrum, cerebellum, amygdala, and, notably, the hippocampal formation. However, the precise mechanism behind these effects remains unclear. Within this study, we conducted a comprehensive examination of the impacts of tramadol on the CNS, specifically focusing on hippocampal formation.

Methods

In this study, we collected relevant articles published between 2000 and 2022 by conducting searches using specific keywords, including tramadol, tramadol hydrochloride, central nervous system, hippocampus, and hippocampal formation, in various databases.

Findings

The results of this study proposed several processes by which tramadol may impact the CNS, including the induction of apoptosis, autophagy, excessive production of free radicals, and dysfunction of cellular organelles. These processes ultimately lead to disturbances in neural cell function, particularly within the hippocampus. Furthermore, it is revealed that tramadol administration led to a significant decrease in the neural cell count and the volume of various regions within the brain and spinal cord.

Conclusion

Consequently, neuropsychological impairments, such as memory formation, attention deficits, and cognitive impairment, may happen. This finding highlights the potential impacts of tramadol on neural structures and warrants further investigation.

Opioids-Induced Long QT Syndrome: A Challenge to Cardiac Health

The challenge posed by opioid overdose has become a significant concern for health systems due to the complexities associated with drug prohibition, widespread clinical use, and potential abuse. In response, healthcare professionals have primarily concentrated on mitigating the hallucinogenic and respiratory depressant consequences of opioid overdose to minimize associated risks. However, it is crucial to acknowledge that most opioids possess the capacity to prolong the QT interval, particularly in cases of overdose, thereby potentially resulting in severe ventricular arrhythmias and even sudden death if timely intervention is not implemented. Consequently, alongside addressing the typical adverse effects of opioids, it is imperative to consider their cardiotoxicity. To enhance comprehension of the correlation between opioids and arrhythmias, identify potential targets for prompt intervention, and mitigate the hazards associated with clinical utilization, an exploration of the interaction between drugs and ion channels, as well as their underlying mechanisms, becomes indispensable. This review primarily concentrates on elucidating the impact of opioid drugs on diverse ion channels, investigating recent advancements in this domain, and attaining a deeper understanding of the mechanisms underlying the prolongation of the QT interval by opioid drugs, along with potential interventions.

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.

Exploring the potential use of melatonin as a modulator of tramadol-induced rewarding effects in rats

Background

Melatonin is responsible for regulating the sleep-wake cycle and circadian rhythms in mammals. Tramadol, a synthetic opioid analgesic, is used to manage moderate to severe pain but has a high potential for abuse and dependence. Studies have shown that melatonin could be a potential modulator to reduce tramadol addiction.

Methods

Male Wistar rats were used to investigate the effect of melatonin on tramadol-induced place preference. The rats were divided into four groups: control, tramadol, tramadol + melatonin (single dose), and tramadol + melatonin (repeated doses). Tramadol was administered intraperitoneally at 40 mg/kg, while melatonin was administered at 50 mg/kg for both the single dose and repeated-dose groups. The study consisted of two phases: habituation and acquisition.

Results

Tramadol administration produced conditioned place preference (CPP) in rats, indicating rewarding effects. However, melatonin administration blocked tramadol-induced CPP. Surprisingly, repeated doses of melatonin were ineffective and did not reduce the expression of CPP compared to that of the single dose administration.

Conclusion

The study suggests that melatonin may be a potential therapeutic option for treating tramadol addiction. The results indicate that melatonin attenuates the expression of tramadol-induced CPP, supporting its uses as an adjunct therapy for managing tramadol addiction. However, further studies are needed to investigate its effectiveness in humans.

Pain management in chronic pancreatitis

Pain in chronic pancreatitis (CP) is difficult to manage. Many patients suffer from inadequate pain relief, completely incapacitating them in their daily activities. Historically, despite their well-known adverse effects, opioids have been the pillar of treatment regimens in painful CP. The management is now gradually evolving with a better understanding of the underlying pathophysiology of CP-related pain. Clinicians should follow a holistic approach to the management of CP-associated pain, which must involve lifestyle changes that are coupled with analgesic medications and other pain-relieving interventions. Furthermore, there is no easy cure for vanquishing CP-associated pain. Each patient must be evaluated on a case-by-case basis by a multidisciplinary team to decide which treatment option is best suited for that individual.

Effects of tramadol via a µ-opioid receptor on pancreatic ductal adenocarcinoma in vitro and in vivo

INTRODUCTION

Tramadol, a weak opioid anesthetic, is used for pain management in patients with cancer, but the effects of tramadol on cancer via µ-opioid receptor are still unknown. We assessed the effects of tramadol on pancreatic ductal adenocarcinoma using transgenic mice (LSL-KrasG12D/+; Trp53flox/flox; Pdx-1cre/+ ).

METHODS

Six-week-old transgenic mice were orally administered 10 mg/kg/day tramadol (n=12), 10 mg/kg/day tramadol and 1 mg/kg/day naltrexone (n=9), or vehicle water (n=14) until the humane endpoint. Cancer-related pain and plasma cytokine levels were assessed by the mouse grimace scale and cytokine array, respectively. Tumor status was determined histopathologically. Tramadol's effects on proliferation and invasion in pancreatic ductal adenocarcinoma cell lines were studied in vitro.

RESULTS

Tramadol with/without naltrexone improved mouse grimace scale scores while decreasing inflammatory cytokines such as tumor necrosis factor-α and interleukin-6. Proliferative Ki-67 and cyclins decreased by tramadol, while local M1-like tumor-associated macrophages increased by tramadol, which was blocked by naltrexone. Meanwhile, tramadol with/without naltrexone reduced juxta-tumoral cancer-associated fibroblasts and M2-like tumor-associated macrophages. Tumor-associated neutrophils, natural killers, and cytotoxic T cells were not altered. Tramadol decreased the proliferative and invasive potentials of pancreatic ductal adenocarcinoma cell lines via decreasing cyclins/cyclin-dependent kinases, which was partially reversed by naltrexone.

CONCLUSIONS

These findings imply that tramadol might be a useful anesthetic for pancreatic ductal adenocarcinoma: inhibiting the proliferation and invasion along with increasing antitumor M1-like tumor-associated macrophages via the µ-opioid receptor, while improving cancer-associated pain possibly through the antitumor effects with the decrease of inflammatory cytokines.

Exciting Advances in Sustainable Spectrophotometric Micro-Quantitation of an Innovative Painkiller "Tramadol and Celecoxib" Mixture in the Presence of a Toxic Impurity, Promoting Greenness and Whiteness Studies

BACKGROUND

Tramadol (TRM) and celecoxib (CLX) form a novel mixture that helps relieve acute pain when other painkillers have no action. It is also reported that these drugs, TRM and CLX, are used to control COVID-19 symptoms.

OBJECTIVE

The current work highlights three important pillars of modern pharmaceutical analysis, which are as follows; impurity profiling, greenness/whiteness studies and simplicity accompanied by sensitivity. Since 4-methyl acetophenone inhibits the human carbonyl reductase enzyme (type I) and since this compound may pose a health risk, it is crucial to regulate its concentration in all dosage forms of CLX.

METHODS

Two simple and green spectrophotometric methods were developed, namely third derivative (D3) and Fourier self- deconvulation (FSD), for resolving severely overlapped spectra of TRM and CLX in the presence of 4-methyl acetophenone (4-MAP) as a process-related impurity in their novel tablet combination.

RESULTS

The two approaches showed acceptable linearity with an excellent correlation coefficient. In both methods, TRM was measured when CLX and 4-methyl acetophenone were zero-crossing. The same procedure was applied for measuring CLX and its process-related impurity 4-MAP.

CONCLUSION

The methodologies developed were thoroughly validated in compliance with ICH (International Council on Harmonisation) guidelines. Student t- and F-tests revealed no statistically significant variation among the current methods and the reported method.

HIGHLIGHTS

No spectrophotometric methods have been published previously for the simultaneous analysis of TRM and CLX along with 4-MAP. As a result, the newly developed spectrophotometric approaches have great relevance and originality in the field of pharmaceutical analysis.

Is the reliability of wastewater-based epidemiology affected by season? Comparative analysis with pharmaceuticals prescriptions

Wastewater-based epidemiology (WBE) has been already proposed by several authors for estimating the consumption of drugs, mainly the illicit ones. However, not much information is available about the actual reliability of this tool given the absence of comparison with the actual consumption. This work aims to evaluate the reliability of the WBE as a tool for estimating the consumption of pharmaceuticals in urban area. Measured consumption back-calculated with a WBE approach was compared with prescription of pharmaceutical products as "control." Moreover, seasonal influence on (i) pharmaceutical consumption, (ii) load of pharmaceutical products in the sewer system, and (iii) reliability of WBE was evaluated. Ciprofloxacin, sulfamethoxazole, metoprolol, carbamazepine, and citalopram were estimated by WBE with a difference respect to the "control" value lower than 0.2 order of magnitude while only trimethoprim and sotalol exceeded the 0.5 order of magnitude of difference but below the 1 order of magnitude. Sedatives were the best represented by WBE (on average 0.15 order of magnitude of difference compared to prescription data). However, further studies are suggested to fully estimate the influence of the type of APs on the reliability of the WBE. Seasonal patterns were found for the load of ciprofloxacin in the sewer and for the consumption of sulfamethoxazole and trimethoprim by population but seasonal changes did not have a significant impact (p > 0.05) on the reliability of WBE. Despite some gaps remained to optimize the reliability of the tool, WBE can be considered a valid method to estimate the consumption of prescribed drugs from the analysis of the sewer system.

The Effect of Epidural Analgesia on Quality of Recovery (QoR) after Open Radical Nephrectomy: Randomized, Prospective, and Controlled Trial

No studies are currently evaluating the quality of recovery (QoR) after open radical nephrectomy (ORN) and epidural morphine analgesia. This was a randomized, prospective, and controlled study that explored the QoR on the first postoperative day after ORN. Eighty subjects were randomized into two groups. The first group received general anesthesia combined with epidural anesthesia and postoperative epidural analgesia with morphine and ropivacaine. The second group received general anesthesia and continuous postoperative intravenous analgesia with tramadol. Both groups received multimodal analgesia with metamizole. The primary outcome measure was the total QoR-40 score. The secondary outcome measures were QoR-15, QoR-VAS, and the visual analog scale (VAS) for pain, anxiety, and nausea. The median difference in the QoR-40 score after 24 postoperative hours between the two groups of patients was 10 (95% CI: 15 to 5), p < 0.0001. The median score and IQR of QoR-40 during the first 24 postoperative hours in the epidural group was 180 (9.5), and in the control group, it was 170 (13). The general independence test for secondary outcomes between groups was significant (p < 0.01). QoR-VAS was correlated with QoR-40 (r = 0.63, p ≤ 0.001) and with QoR-15 (r = 0.54, p ≤ 0.001). The total QoR-40 and QoR-15 alpha coefficients with a 95% CI were 0.88 (0.85-0.92) and 0.73 (0.64-0.81), respectively. There was a significant difference in the QoR between the epidural and the control groups after ORN. The QoR-40 and QoR-15 showed good convergent validity and reliability.

Risk Factors for Respiratory Depression Associated with Tramadol Based on the Global Pharmacovigilance Database (VigiBase)

Tramadol, a weak μ-opioid receptor agonist, has been used worldwide for pain management. It is considered to have a favorable safety profile without serious adverse events; however, safety issues of respiratory depression were proposed by regulatory governments. We aimed to examine the risk and contributing factors associated with tramadol-related respiratory depression using a real-world database, VigiBase. Disproportionality analysis of tramadol and tramadol/paracetamol was performed using proportional reporting ratios, reporting odds ratios, and information components for all drugs and opioids. Factors related to respiratory depression, including sex, age, presence of abuse, death, and various concomitant medications, were evaluated. Among 140,721 tramadol reports, respiratory depression was reported in 1126 cases, 81.3% of which were deemed serious. Five adverse events were detected as signals of tramadol-related acute central respiratory depression (ACRD) in 882 reports. A higher proportion of ACRD cases in children and adolescents was observed than all adverse events cases of tramadol. Concomitant users of CYP2D6 inhibitors, opioids, benzodiazepines, and anti-depressant drugs showed a higher proportion in ACRD cases than non-ACRD cases. ACRD was related to drug abuse and death. This pharmacovigilance study, using VigiBase, confirmed a high risk of respiratory depression (a serious, potentially fatal adverse event) secondary to the use of tramadol, especially in pediatric patients, drug abusers, or during concomitant use of opioids, benzodiazepines, or antidepressants.

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.

Association of tramadol use with risk of hip fractures in patients with osteoarthritis: A systematic review and meta-analysis of observational studies

OBJECTIVE

Many studies have reported conflicting results for the use of tramadol with the risk of fractures, especially hip fractures. This systematic review and meta-analysis study aimed to evaluate the association of tramadol use versus codeine use with the risk of hip fracture for the first time.

METHODS

PubMed, Scopus, Google Scholar, and Web of Science databases were searched with specific keywords to find studies that examined the association of tramadol use with hip fracture risk in patients with osteoarthritis up to May 2023. The risk of hip fracture secondary to tramadol versus codeine use was estimated based on age and sex. This systematic review was conducted based on the PRISMA checklist. Heterogeneity between studies was evaluated using Cochran's Q and I2 tests. Egger's test was used to check publication bias. The Newcastle-Ottawa Checklist (NOS) was used to assess the quality of the studies.

FINDINGS

Ten studies with 1,939,293 participants were reviewed. The majority of participants were female. Based on the study evaluation checklist, most studies were of good quality. Tramadol use significantly increases the overall risk of hip fracture. (HR: 1.32, 95% CI: 1.14, 1.51, P: 0.001, I2:19.3%) Tramadol use significantly increases the risk of hip fracture in men (HR: 1.48, 95% CI: 1.24, 1.73, P: 0.001 I2:35%) and age ≤65 years (HR: 1.63, 95% CI: 1.45, 1.80, P: 0.001, I2:0%).

CONCLUSION

The use of tramadol significantly increases the risk of hip fracture. This increased risk of hip fracture was greater in males younger than 65 years.

Photoredox and NHC Enabled Deoxygenative Alcohol Homologation via Formal 1,2-Addition

A highly efficient photoinduced iron-catalyzed method has been developed for the direct use of alcohols as surrogates for organometallic reagents in the synthesis of tertiary alcohols. This method can be applied to both primary and secondary alcohols with diverse structures, enabling their reaction with aryl ketones under mild conditions. A variety of functional groups, including those that are typically reactive under conventional tertiary alcohol synthesis conditions, are compatible. Mechanistically, this reaction proceeds through the direct addition of the radical to the carbonyl pathway.

Neurophysiology of corneal neuropathic pain and emerging pharmacotherapeutics

The altered activity generated by corneal neuronal injury can result in morphological and physiological changes in the architecture of synaptic connections in the nervous system. These changes can alter the sensitivity of neurons (both second-order and higher-order projection) projecting pain signals. A complex process involving different cell types, molecules, nerves, dendritic cells, neurokines, neuropeptides, and axon guidance molecules causes a high level of sensory rearrangement, which is germane to all the phases in the pathomechanism of corneal neuropathic pain. Immune cells migrating to the region of nerve injury assist in pain generation by secreting neurokines that ensure nerve depolarization. Furthermore, excitability in the central pain pathway is perpetuated by local activation of microglia in the trigeminal ganglion and alterations of the descending inhibitory modulation for corneal pain arriving from central nervous system. Corneal neuropathic pain may be facilitated by dysfunctional structures in the central somatosensory nervous system due to a lesion, altered synaptogenesis, or genetic abnormality. Understanding these important pathways will provide novel therapeutic insight.

Development, Physicochemical Characteristics and Pharmacokinetics of a New Sustained-Release Bilayer Tablet Formulation of Tramadol with an Immediate-Release Component for Twice-Daily Administration

BACKGROUND AND OBJECTIVE

There are some potential concerns about the currently marketed solid oral dosage forms of tramadol, including decreased adherence to immediate-release (IR) formulations due to the high number of doses taken each day and the slow rise in the blood tramadol concentration after administration of sustained-release (SR) formulations, which may not achieve a rapid analgesic effect. To overcome these potential concerns, a twice-daily double-layered tablet formulation of tramadol comprising IR and SR layers was developed. This article reports studies that assessed its physicochemical and pharmacokinetic properties.

METHODS

Dissolution tests of five bilayer tablet formulations (designated tablets A-E) and pharmacokinetic studies of tablets A and B were conducted to investigate the appropriate ratio of the IR/SR layers in the double-layered tablet. Additionally, pharmacokinetic studies of three finished dosage formulations (tablets C-E) were performed in healthy adult males to investigate the effect of food intake on drug absorption.

RESULTS

Adjusting the excipients and tramadol content in the IR and SR layers of tablets A-E altered their dissolution profiles in a manner that could be predicted based on their compositions. The IR layer was released within 15 min, and the SR layer was slowly released over 10 h. In the pharmacokinetic study, the time to maximum plasma concentration (tmax) of tramadol after administration of tablets A (IR:SR: 20:80 mg) and B (40:60 mg) was shorter than that of a commercially available SR tablet, and the half-life (t1/2) was longer than that of a commercially available IR tablet. For tablets C-E, administration after food did not affect the area under the concentration-time curve (AUC) or maximum drug concentration (Cmax) of tramadol, but the tmax was prolonged by about 1 h compared with administration in fasting conditions. The mean ± standard deviation tmax and t1/2 for tablet D (IR:SR: 35:65 mg) in the fasting condition was 1.09 ± 0.56 h and 7.82 ± 0.85 h, respectively. The respective values in the fed condition were 2.47 ± 1.06 h and 7.12 ± 0.85 h, respectively.

CONCLUSIONS

To address the potential concerns regarding existing formulations of tramadol, a twice-daily, extended-release bilayer formulation of tramadol consisting of an IR and SR layer was developed. Pharmacokinetic studies confirmed that the plasma tramadol concentration increased quickly after administration and was maintained over a long period of time.

Coenzyme Q10 attenuates neurodegeneration in the cerebellum induced by chronic exposure to tramadol

BACKGROUND

Chronic use of tramadol can cause neurotoxic effects and subsequently cause neurodegeneration in the cerebellum. The main damage mechanisms identified are oxidative stress and inflammation. Currently, we investigated the effects of coenzyme Q10 (CoQ10) in attenuates of neurodegeneration in the cerebellum induced by chronic exposure to tramadol.

MATERIAL AND METHODS

Seventy-two male mature albino rats were allocated into four equal groups, including; non-treated group, CoQ10 group (which received CoQ10 at 200 mg/kg/day orally for three weeks), tramadol group (which received tramadol hydrochloride at 50 mg/kg/day orally for three weeks), and tramadol+CoQ10 group (which received tramadol and CoQ10 at the same doses as the previous groups). Tissue samples were obtained for stereological, immunohistochemical, biochemical, and molecular evaluations. Also, functional tests were performed to evaluate behavioral properties.

RESULTS

We found a significant increase in stereological parameters, antioxidant factors (catalase, glutathione, and superoxide dismutase), and behavioral function scores in the tramadol+CoQ10 group compared to the tramadol group (p < 0.05). In addition, malondialdehyde levels, the density of apoptotic cells, as well as the expression of pro-inflammatory (tumor necrosis factor-alpha, interleukin 1 beta, and interleukin 6) and autophagy (lysosome-associated membrane protein 2, autophagy-related 5, beclin 1, and autophagy-related 12) genes were considerably reduced in the tramadol+CoQ10 group compared to the tramadol group (p < 0.05).

CONCLUSION

We conclude that the administration of CoQ10 has neuroprotective effects in the cerebellum of rats that have chronic exposure to tramadol.

Phase III study of bilayer sustained-release tramadol tablets in patients with cancer pain: a double-blind parallel-group, non-inferiority study with immediate-release tramadol capsules as an active comparator

PURPOSE

We investigated whether twice-daily administration of a bilayer tablet formulation of tramadol (35% immediate-release [IR] and 65% sustained-release) is as effective as four-times-daily IR tramadol capsules for managing cancer pain.

METHODS

This randomized, double-blind, double-dummy, active-comparator, non-inferiority study enrolled opioid-naïve patients using non-steroidal anti-inflammatory drugs or acetaminophen (paracetamol) to manage cancer pain and self-reported pain (mean value over 3 days ≥ 25 mm on a 100-mm visual analog scale [VAS]). Patients were randomized to either bilayer tablets or IR capsules for 14 days. The starting dose was 100 mg/day and could be escalated to 300 mg/day. The primary endpoint was the change in VAS (averaged over 3 days) for pain at rest from baseline to end of treatment/discontinuation.

RESULTS

Overall, 251 patients were randomized. The baseline mean VAS at rest was 47.67 mm (range: 25.6-82.7 mm). In the full analysis set, the adjusted mean change in VAS was - 22.07 and - 19.08 mm in the bilayer tablet (n = 124) and IR capsule (n = 120) groups, respectively. The adjusted mean difference was - 2.99 mm (95% confidence interval [CI] - 7.96 to 1.99 mm). The upper 95% CI was less than the predefined non-inferiority margin of 7.5 mm. Other efficacy outcomes were similar in both groups. Adverse events were reported for 97/126 (77.0%) and 101/125 (80.8%) patients in the bilayer tablet and IR capsule groups, respectively.

CONCLUSION

Twice-daily administration of bilayer tramadol tablets was as effective as four-times-daily administration of IR capsules regarding the improvement in pain VAS, with comparable safety outcomes.

CLINICAL TRIAL REGISTRATION

JapicCTI-184143/jRCT2080224082 (October 5, 2018).

Predictors for the Clinical Efficacy of Tramadol for Cancer Pain

CONTEXT

Tramadol is conditionally recommended for cancer pain and is a less expensive drug compared to strong opioids. Thus, tramadol may help reduce health care costs.

OBJECTIVES

To investigate factors that predict the clinical efficacy of tramadol for cancer pain.

METHODS

A retrospective study using electronic medical records was conducted on patients who received tramadol for cancer pain from January 2016 to December 2020. Patients who continued tramadol for >28 days or discontinued tramadol before 28 days owing to pain improvement were considered as clinical efficacy cases.

RESULTS

We identified 183 eligible patients; 104 cases had clinical efficacy. The median starting tramadol daily dose was 100 mg, and the median administration duration was 22 days. Overall, 169 patients (92.3%) discontinued tramadol; pain improvement was the most common reason (34.9%). Age (>70 years), a performance status of 0-1, and an albumin-bilirubin grade of 1 were independent predictors for the clinical efficacy of tramadol. Patients with multiple predictors had significantly higher achievement rates than those without.

CONCLUSION

Tramadol could have greater clinical efficacy for cancer pain in patients who are elderly, have good performance status, and have good liver function.

Use of tramadol as analgesic alternative in Harris hawk (Parabuteo unicinctus)

BACKGROUND

The Harris hawk is a bird of prey susceptible to traumatic injuries because it is useful for several purposes such as conservancy, biological control and falconry. Once received in rehabilitation centres or specialized clinics, it is necessary to provide proper analgesia.

OBJECTIVES

The aim of this study is to demonstrate the analgesic efficacy of tramadol in Harris hawks (PISADOL 50 PiSA Agropecuaria, S.A. de C.V. Calle 1 Norte, Manzana 2-25 Parque Industrial Tula Atitalaquia, Hgo, México), by the assessment of nociceptive threshold.

METHODS

A total of 24 adult Harris hawks were selected from a rehabilitation centre. The birds were randomly divided into four groups: control (saline solution), 5.0, 15.0 and 30.0 mg/kg of intramuscular tramadol. Nociception was produced with electrical stimuli of 9 V, applied in propatagial skin at 1, 5, 10, 20, 30, 45, 60, 90, 120, 180, 240, 300 and 360 min, assessing the nociceptive threshold and sedative effects produced by each treatment.

RESULTS

No difference was observed between control and tramadol group 5 mg/kg. At 15 mg/kg, the pain threshold increased from 20 to 240 min, with minimal sedative effects. At 30 mg/kg, there was a marked increase in pain threshold from 10 to 300 min, and sedative effects like wing and head drooping for a period of 90 min.

CONCLUSIONS

Tramadol can be an analgesic alternative for Harris's hawks, as it decreases the response to painful stimuli in this species when administered by intramuscular route.

Weaving the next generation of (bio)materials: Semi-interpenetrated and interpenetrated polymeric networks for biomedical applications

Advances in polymer science have led to the development of semi-interpenetrated and interpenetrated networks (SIPN/IPN). The interpenetration procedure allows enhancing several important properties of a polymeric material, including mechanical properties, swelling capability, stimulus-sensitive response, and biological performance, among others. More interestingly, the interpenetration (or semi-interpenetration) can be achieved independent of the material size, that is at the macroscopic, microscopic, or nanometric scale. SIPN/IPN have been used for a wide range of applications, especially in the biomedical field, including tissue engineering, delivery of chemical compounds or biological macromolecules, and multifunctional systems as theragnostic platforms. In the last years, this fascinating field has gained a great interest in the area of polymers for therapeutics; therefore, a comprehensive revision of the topic is timely. In this review, we describe in detail the most relevant synthetic approaches to fabricate polymeric IPN and SIPN, ranging from nanoscale to macroscale. The advantages of typical synthetic methods are analyzed, as well as novel and promising trends in the field of advanced material fabrication. Furthermore, the characterization techniques employed for these materials are summarized from physicochemical, thermal, mechanical, and biological perspectives. The applications of novel (semi-)interpenetrated structures are discussed with a focus on drug delivery, tissue engineering, and regenerative medicine, as well as combinations thereof.

Evaluation and Treatment of Acute Trauma Pain in Older Adults

In the context of an ageing population, the demographic sands of trauma are shifting. Increasingly, trauma units are serving older adults who have sustained injuries in low-energy falls from a standing height. Older age is commonly associated with changes in physiology, as well as an increased prevalence of frailty and multimorbidity, including cardiac, renal and liver disease. These factors can complicate the safe and effective administration of analgesia in the older trauma patient. Trauma services therefore need to adapt to meet this demographic shift and ensure that trauma clinicians are sufficiently skilled in treating pain in complex older people. This article is dedicated to the management of acute trauma pain in older adults. It aims to highlight the notable clinical challenges of managing older trauma patients compared with their younger counterparts. It offers an overview of the evidence and practical opinion on the merits and drawbacks of commonly used analgesics, as well as more novel and emerging analgesic adjuncts. A search of Medline (Ovid, from inception to 7 November 2022) was conducted by a medical librarian to identify relevant articles using keyword and subject heading terms for trauma, pain, older adults and analgesics. Results were limited to articles published in the last 10 years and English language. Relevant articles' references were hand-screened to identify other relevant articles. There is paucity of dedicated high-quality evidence to guide management of trauma-related pain in older adults. Ageing-related changes in physiology, the accumulation of multimorbidity, frailty and the risk of inducing delirium secondary to analgesic medication present a suite of challenges in the older trauma patient. An important nuance of treating pain in older trauma patients is the challenge of balancing iatrogenic adverse effects of analgesia against the harms of undertreated pain, the complications and consequences of which include immobility, pneumonia, sarcopenia, pressure ulcers, long-term functional decline, increased long-term care needs and mortality. In this article, the role of non-opioid agents including short-course non-steroidal anti-inflammatory drugs (NSAIDs) is discussed. Opioid selection and dosing are reviewed for older adults suffering from acute trauma pain in the context of kidney and liver disease. The evidence base and limitations of other adjuncts such as topical and intravenous lidocaine, ketamine and regional anaesthesia in acute geriatric trauma are discussed.

Stroke-Induced Central Pain: Overview of the Mechanisms, Management, and Emerging Targets of Central Post-Stroke Pain

The incidence of stroke plays the foremost role in the genesis of central neuropathic pain. Central post-stroke pain (CPSP) is a central pain arising from a vascular lesion in the central nervous system that elicits somatosensory deficits, often contralateral to stroke lesions. It is expressed as continuous or intermittent pain accompanied by sensory abnormalities like dysesthesia and allodynia. CPSP remains de-emphasized due to the variation in onset and diversity in symptoms, besides the difficulty of distinguishing it from other post-stroke pains, often referred to as a diagnosis of exclusion. Spinothalamic dysfunction, disinhibition of the medial thalamus, and neuronal hyperexcitability combined with deafferentation in thalamocortical regions are the mechanisms underlying central pain, which play a significant role in the pathogenesis of CPSP. The treatment regimen for CPSP seems to be perplexed in nature; however, based on available studies, amitriptyline and lamotrigine are denoted as first-line medications and non-pharmacological choices may be accounted for cases intractable to pharmacotherapy. This review attempts to provide an overview of the mechanisms, existing management approaches, and emerging targets of CPSP. A profound understanding of CPSP aids in optimizing the quality of life among stroke sufferers and facilitates further research to develop newer therapeutic agents for managing CPSP.

Modulation of social and depression behaviors in cholestatic and drug-dependent mice: possible role of opioid receptors

Objectives

Social behavior, a set of motivating activities critical for survival, is disturbed in cholestasis conditions and many substance abusers as well as psychiatric disorders. The documented loss of social interest in cholestatic patients may be associated with depressive symptoms. Interestingly, the endogenous opioid system is involved in the modulation of depression.

Methods in this research

, we assessed the effect of cholestasis and drug dependence on social and depression behaviors using the Three-Chamber Paradigm Test, Forced Swim Test (FST), and Tail Suspension Test (TST) as well as Open Field Test (OFT) in male NMRI mice.

Results

The results indicated that alone administration of morphine and tramadol, as well as co-administration of them, increased social motivation and novelty but decreased depression in bile duct ligated mice. Whereas, alone administration of naloxone (a µ-opioid receptor antagonist) and co-administration of it along with morphine and tramadol decreased social motivation and novelty while enhanced depression in the sham-operated and bile duct ligated mice. These administrations of drugs did not change locomotor activity compared to the control group.

Conclusion

In conclusion, it appears that (i) both cholestasis and drug dependence impaired social motivation behavior, as well as induced depression-like behavior in the bile duct, ligated mice, (ii) alone administration of morphine and tramadol as well as co-treatment of them may protect against cholestasis and drug dependence induced abnormal behaviors, (iii) µ-opioid receptors play an important role in modulation of social motivation and depression behaviors in mice.

Formulation of pH-responsive highly swellable hydrogel scaffolds for controlled release of tramadol HCl: characterization and biocompatibility evaluation

Introduction: The objective of current project was to formulate a system for controlled delivery of Tramadol HCl (TRD), an opioid analgesic used in the treatment of moderate to severe pain. Methods: For this purpose, a pH responsive AvT-co-poly hydrogel network was formulated through free radical polymerization by incorporating natural polymers i.e., aloe vera gel and tamarind gum, monomer and crosslinker. Formulated hydrogels were loaded with Tramadol HCl (TRD) and evaluated for percent drug loading, sol-gel fraction, dynamic and equilibrium swelling, morphological characteristics, structural features and in-vitro release of Tramadol HCl. Results and Discussions: Hydrogels were proved to be pH sensitive as remarkable dynamic swelling response ranging within 2.94g/g-10.81g/g was noticed at pH 7.4 as compared to pH 1.2. Percent drug loading was in the range of 70.28%-90.64% for all formulations. Thermal stability and compatibility of hydrogel components were validated by DSC analysis and FTIR spectroscopy. Controlled release pattern of Tramadol HCl from the polymeric network was confirmed as maximum release of 92.22% was observed for over a period of 24 hours at pH 7.4. Moreover, oral toxicity studies were also conducted in rabbits to investigate the safety of hydrogels. No evidence of any toxicity, lesions and degeneration was reported, confirming the biocompatibility and safety of grafted system.

A UiO-66-NH2 MOF/PAMAM Dendrimer Nanocomposite for Electrochemical Detection of Tramadol in the Presence of Acetaminophen in Pharmaceutical Formulations

In this work, we prepared a novel electrochemical sensor for the detection of tramadol based on a UiO-66-NH₂ metal-organic framework (UiO-66-NH₂ MOF)/third-generation poly(amidoamine) dendrimer (G3-PAMAM dendrimer) nanocomposite drop-cast onto a glassy carbon electrode (GCE) surface. After the synthesis of the nanocomposite, the functionalization of the UiO-66-NH₂ MOF by G3-PAMAM was confirmed by various techniques including X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), field emission-scanning electron microscopy (FE-SEM), and Fourier transform infrared (FT-IR) spectroscopy. The UiO-66-NH₂ MOF/PAMAM-modified GCE exhibited commendable electrocatalytic performance toward the tramadol oxidation owing to the integration of the UiO-66-NH₂ MOF with the PAMAM dendrimer. According to differential pulse voltammetry (DPV), it was possible to detect tramadol under optimized circumstances in a broad concentration range (0.5 μM-500.0 μM) and a narrow limit of detection (0.2 μM). In addition, the stability, repeatability, and reproducibility of the presented UiO-66-NH₂ MOF/PAMAM/GCE sensor were also studied. The sensor also possessed an acceptable catalytic behavior for the tramadol determination in the co-existence of acetaminophen, with the separated oxidation potential of ΔE = 410 mV. Finally, the UiO-66-NH₂ MOF/PAMAM-modified GCE exhibited satisfactory practical ability in pharmaceutical formulations (tramadol tablets and acetaminophen tablets).

Carbamazepine, venlafaxine, tramadol, and their main metabolites: Toxicological effects on zebrafish embryos and larvae

Pharmaceutical compounds and their metabolites are found in natural and wastewater. However, investigation of their toxic effects on aquatic animals has been neglected, especially for metabolites. This work investigated the effects of the main metabolites of carbamazepine, venlafaxine and tramadol. Zebrafish embryos were exposed (0.1-100 µg/L) for 168hpf exposures to each metabolite (carbamazepine-10,11-epoxide, 10,11-dihydrocarbamazepine, O-desmethylvenlafaxine, N-desmethylvenlafaxine, O-desmethyltramadol, N-desmethyltramadol) or the parental compound. A concentration-response relationship was found for the effects of some embryonic malformations. Carbamazepine-10,11-epoxide, O-desmethylvenlafaxine and tramadol elicited the highest malformation rates. All compounds significantly decreased larvae responses on a sensorimotor assay compared to controls. Altered expression was found for most of the 32 tested genes. In particular, abcc1, abcc2, abcg2a, nrf2, pparg and raraa were found to be affected by all three drug groups. For each group, the modelled expression patterns showed differences in expression between parental compounds and metabolites. Potential biomarkers of exposure were identified for the venlafaxine and carbamazepine groups. These results are worrying, indicating that such contamination in aquatic systems may put natural populations at significant risk. Furthermore, metabolites represent a real risk that needs more scrutinising by the scientific community.

Analysis of umbilical cord tissue as an indicator of in utero exposure to toxic adulterating substances

In utero drug exposure is a significant public health threat to the well-being and normal development of the neonate. Recently, testing of umbilical cord tissue (UCT) has been employed to measure illicit drug exposure, as drugs used by the mother during the third trimester may be retained in the UCT. Focus has also been given to potential adverse health effects among drug users, resulting from exposure to pharmacologically active adulterants and cutting agents in the street drug supply. The in utero effects of these substances have not been well studied in humans, nor has their presence been demonstrated as a means for assessing adverse health effects in the neonate. Here, we describe the application of a novel test method to analyze UCT for the presence of more than 20 common adulterating/cutting substances via LC/Q-TOF. In total, 300 de-identified UCT samples were analyzed-all had previously tested positive for cocaine or opiates. Generally, the positivity rates of individual compounds were similar between the Cocaine and Opiates Subgroups, apart from levamisole, xylazine, dipyrone (metabolites), and promethazine. Many of the adulterants used in the street drug supply do have legitimate medicinal/therapeutic uses, including several of the compounds most frequently detected in this study. Caffeine and lidocaine were the most frequently identified compounds both individually (>70% each) and in combination with each other. Alternatively, levamisole, an adulterant with no legitimate therapeutic use, was present in 12% of cases. Importantly, this data demonstrates that the detection of traditional drugs of abuse may serve as indicators of potential in utero exposure to toxic adulterating substances during gestation. While there is cause for concern with respect to any unintentional drug exposure, illicit drug use during pregnancy, including uncontrolled dosing, poly-adulterant consumption, and the interactions of these drug mixtures, produces a significant public health threat to the neonate which warrants further study.