Tramadol: a review of its use in perioperative pain

Poly-taurine/poly-L-glutamic acid double-layer coating as potential candidates for surface modification of carbon felt electrode for discrimination and simultaneous detection of morphine and tramadol

An ultrasensitive and reliable electrochemical scaffold was designed for the individual and simultaneous measurement of morphine (Mor) and tramadol (Trm) addictive and illegal drugs, utilizing a cost-effective and flexible carbon felt electrode modified with double-layer poly-taurine/poly-L-glutamic acid (P(Tau)/P(Glu)/CF). It is worth noting that drugs have now become a part of daily life in all societies, and the consumption of tranquilizers and opiates such as Mor and Trm has also increased. Given the frequent co-use of Mor and Trm, accurate and reliable methods for their simultaneous measurement are crucial. Simultaneous diagnostics make the determination more efficient and cost-effective by reducing the need for multiple sensors. Surface modification of CFE was carried out by a green approach, facile and straightforward route by layer-by-layer electropolymerization, forming a thin polymeric film with abundant functional groups responsible for anchoring narcotic drugs. The P(Tau)/P(Glu)/CFE composite showed an exceptionally high rate of active site exposure and proper electrochemical activity, attributed to the synergistic effects of the constituent materials. P(Tau)/P(Glu)/CFE was successfully used to detect saliva, urine, plasma, and body sweat samples with satisfactory recoveries.

The Effectiveness of Tramadol in Pain Relief in Chronic Diseases: A Review Based on Clinical Trials

Tramadol is a synthetic opioid with a central effect from the aminocyclohexanol group, which has two main mechanisms of action, including as a weak agonist of opioid receptors and as a norepinephrine and serotonin reuptake inhibitor. The present study presents a review based on clinical trials designed in 2023. In July 2023, six international databases, including Medline/PubMed, ProQuest, Scopus, EMBASE, Google Scholar, and ISI (Web of Science), were searched and 58 articles were included in the study. The results of most studies showed that tramadol can be used as an analgesic drug, although in some studies it was shown that tramadol is not therapeutically superior in reducing pain compared to other treatments. Also, complications related to this treatment have been reported in some studies. Physicians should consider these factors to prevent drug toxicity, poor pain relief, use disorder in patients, and unpredictable complications. It should be noted that there is not enough evidence to support the long-term effectiveness of tramadol, but this argument also extends to nonopioid and other types of opioid analgesics, and the lack of long-term trials is due to regulatory and ethical issues. Although opioids can cause addiction when used for a long time, tramadol has a reasonable safety profile. According to the patient's condition and the clinical judgment of the medical professional, tramadol can be prescribed for patients, but the consequences of its use must be considered and a personalized treatment algorithm should be selected if the benefits outweigh the risks of the drug.

Do Psychological Factors Affect Life Satisfaction and Pain Interference in Spine Surgery Patients? A 12-Month Follow-Up Study

Background/Objectives: Psychological factors impact patient-reported outcome measures (PROMs). This study assessed the influence of preoperative anxiety, depression, and resilience on postoperative pain interference and life satisfaction one year after spine surgery. Methods: This study was a secondary analysis of a study involving 120 patients who underwent elective spine surgery and were randomly assigned to receive either tramadol-paracetamol (37.5 mg/325 mg; two tablets; n = 61) or placebo (n = 59) twice per day for pain management during the first five postoperative days. Patients completed the Life Satisfaction Scale-4, Brief Pain Inventory, Hospital Anxiety and Depression Scale, and Resilience Scale-14 questionnaires before surgery and at 28 days and 52 weeks post surgery. The primary outcomes were life satisfaction and pain interference at 12 months after spine surgery and their associations with preoperative anxiety, depression, and resilience. Results: Data from 113 patients (94% response rate) were collected at 52 weeks postoperatively. The number of patients reporting satisfaction with their life increased from three (5%) and two (3%) before surgery to 23 (41%) and 19 (34%), while pain interference decreased from a median of 4.1 to 1.2 and from 4.4 to 1.9 on a scale of 0-10 at 12 months in the placebo and tramadol-paracetamol groups, respectively. The linear regression analysis revealed no statistically significant predictive value for preoperative anxiety, depression, or resilience score for life satisfaction and pain interference at 12 months after spine surgery. Conclusions: These results highlight that psychological factors, anxiety, depression, and resilience did not have an impact on postoperative pain outcomes and life satisfaction in patients undergoing spine surgery.

Nickel oxide nanoparticles modified with dimethylglyoxime grafted on a cellulose surface as an efficient adsorbent for thin film microextraction of tramadol in biological fluids followed by its determination using HPLC

In the current study, nickel oxide nanoparticles (NiO NPs) modified with dimethylglyoxime (DMG) were deposited onto the cellulose surface (Ni(DMG)2-NiO-Cell) and used as an efficient adsorbent for thin film microextraction (TFME) of tramadol (TRA). The extracted TRA was determined using a high-performance liquid chromatography-ultraviolet detector (HPLC-UV). NiO NPs were synthesized by co-precipitation method on the surface of the cellulose substrate; afterward, its surface was modified by DMG to increase the extraction capability of the thin film toward TRA. The synthesized NiO-Cell and Ni(DMG)2-NiO-Cell thin films were characterized using various techniques. The effect of modification of the NiO thin film with DMG reagent on the extraction efficiency was investigated. The crucial parameters influencing the extraction efficiency, including extraction time, desorption time, desorption solvent, pH and salt content, were investigated via a one-at-a-time approach. The figures of merit for the developed method were evaluated in urine, plasma, and deionized water under the optimized extraction and desorption condition. The limits of detection and limits of quantification were in the range of 0.1 to 1 ng mL-1 and 0.3 to 3 ng mL-1, respectively, for the studied samples. The linear dynamic ranges of the developed TFME-HPLC-UV method were 0.3-1000, 1-2500, and 3-5000 ng mL-1 for the deionized water, urine, and plasma samples, respectively. The reproducibility and repeatability of the developed method was assayed in terms of intra-day, inter-day, and inter-thin film precisions by conducting six-replicate experiments at the concentration level of 0.1 and 1 μg mL-1, which were in the range of 5.9% to 8.3%. The sufficiency and applicability of the developed TFME-HPLC-UV method was investigated by determining TRA in urine and plasma samples, and the resulting relative recoveries (RR%) were 85.9% and 91.7%, respectively.

Pharmacogenetic Approach to Tramadol Use in the Arab Population

Tramdol is one of most popular opioids used for postoperative analgesia worldwide. Among Arabic countries, there are reports that its dosage is not appropriate due to cultural background. To provide theoretical background of the proper usage of tramadol, this study analyzed the association between several genetic polymorphisms (CYP2D6/OPRM1) and the effect of tramadol. A total of 39 patients who took tramadol for postoperative analgesia were recruited, samples were obtained, and their DNA was extracted for polymerase chain reaction products analysis followed by allelic variations of CYP2D6 and OPRM A118G determination. Numerical pain scales were measured before and 1 h after taking tramadol. The effect of tramadol was defined by the difference between these scales. We concluded that CYP2D6 and OPRM1 A118G single nucleotide polymorphisms may serve as crucial determinants in predicting tramadol efficacy and susceptibility to post-surgical pain. Further validation of personalized prescription practices based on these genetic polymorphisms could provide valuable insights for the development of clinical guidelines tailored to post-surgical tramadol use in the Arabic population.

Comparative Evaluation of the Local Anesthetic Action of Tramadol Hydrochloride With Adrenaline Versus Lidocaine Hydrochloride With Adrenaline for Maxillary Exodontia: A Randomized Control Trial

BACKGROUND

Tramadol hydrochloride (T-HCl) has demonstrated to have a local anesthetic effect similar to lidocaine hydrochloride (L-HCl) when administered locally for minor oral surgical procedures.

PURPOSE

Our study aimed to compare the anesthetic effect of T-HCl versus L-HCl in maxillary premolar extraction.

STUDY DESIGN, SETTING AND SAMPLE

The study is a split-mouth, double-blind randomized clinical trial at the Faculty of Dental Sciences, Ramaiah University of Applied Sciences, Bengaluru, India. The study sample was composed of patients referred for maxillary bicuspid extraction. Patients were excluded from the sample if, allergic to the study drugs, pregnant or lactating females, and smokers.

EXPOSURE VARIABLE

The variable is an anesthetic drug administered for local anesthesia and it is grouped into 2 categories, T-HCl and L-HCl. A supraperiosteal infiltration of T-HCl with adrenaline on one side and L-HCl with adrenaline on the contralateral side was injected.

MAIN OUTCOME VARIABLE

The primary outcome variable was profound anesthesia of T-HCl, where the patient sensed the loss of sensation of touch, temperature, and pain. Secondary outcomes were onset and duration of anesthesia, intraoperative pain, postoperative analgesia, and adverse reactions, were recorded.

ANALYSES

Inferential statistics, the χ2 Test, the Mann-Whitney Test, and the Wilcoxon signed-rank test were used to compare the parameters. The level of significance was set at ≤ 0.05.

RESULTS

A total of 40 patients were included, and 80 teeth were extracted. Profound anesthesia was achieved in all the cases. The mean subjective duration of anesthesia in the T-HCl and L-HCl groups was 130.80 ± 20.01 minutes and 111.40 ± 14.87 minutes, respectively, with a P value of .001. The mean Visual Analogue Scale (VAS) score for pain during the procedure in the T-HCl and L-HCl groups was 0.60 ± 0.67 and 1.10 ± 0.71, respectively, with a P value of .002. The mean Visual Analogue Scale score for pain postoperatively in the T-HCl and L-HCl groups was 0.70 ± 0.72 and 1.40 ± 0.67, respectively, with a P value of .001. Six patients in T-HCl required postoperative analgesia when compared to 18 patients in L-HCl (P value < .003).

CONCLUSIONS AND RELEVANCE

T-HCl provides similar anesthetic outcomes in the extraction of maxillary bicuspids as L-HCl.

Simultaneous determination of tramadol in earwax and urine samples: effects of age, duration time and sex

Background: This study aims to determine the concentrations of tramadol in earwax (μg/g) and urine (μg/ml) samples taken from postoperative patients, to evaluate the sensitivity of earwax (cerumen) as an alternative analyte and compare it with the findings in urine samples. Results: The results indicated that tramadol concentrations in earwax samples were averaged 45.08 μg/g (range: 13.5-107.7 μg/g), whereas tramadol concentrations in urine samples were averaged 4.97 μg/ml (range: 1.57-10.11 μg/ml). There were significant differences when comparing age groups, duration and sex between earwax and urine samples (p < 0.05). Conclusion: Despite the significant differences between earwax and urine samples, earwax can be used as a bioindicator of tramadol detection.

A Review of Core Biopsies in Musculoskeletal Oncology

Biopsy as a procedure is technically simple but conceptually a challenge. The principles of biopsy have remained more or less the same for 3 decades. With the advent of imaging, hospital facilities, and pathology modalities, we feel it is important that these principles are revisited. Uncertainties are spread across the literature regarding this very important first step in the care of an oncology patient. A surgeon planning the biopsy should be equipped with an MRI for planning. A biopsy has to be considered even for a benign-looking lesion. Even though literature is not clear on what kind of biopsy a surgeon should undertake, it is, without doubt, core biopsy has the edge that fine needle biopsies fail to reproduce. Image guidance for a biopsy is paramount for the accuracy of the sample. Pre-biopsy embolization has to be an option in the toolbox of a surgeon. Biopsy samples from an open biopsy or expensive or difficult interventional radiologist-assisted biopsy should undergo a rapid assessment to reduce the error of sample collection and thereby avoid subjecting the patient to a repeat procedure. Even though clean procedures do not require antibiotic prophylaxis, in view of major endoprosthetic implantations in the future, antibiotic use may be justified. An appropriate biopsy set and methodology as per institution experience are described in the paper.

How to manage the dose of drugs in cancer patients with acute kidney injury, practical recommendations

Acute kidney injury (AKI) and chronic kidney disease (CKD) are common in cancer patients. AKI is a brutal and reversible condition which makes it hard to manage from a pharmacological perspective when patients are receiving anticancer regimens and other supportive care drugs, such as anticoagulants, analgesics and other drugs. In contrast to CKD, which is a slow progressive disease, there is no clear guidance on how to manage and/or modify the dosage of drugs during AKI. Indeed, the slow progression of CKD allows physicians to monitor the renal function by using the glomerular filtration rate. Consequently, publications have explored the management of drugs in cancer patients with CKD, which is currently not the same for AKI. There are no recommendations or suggestions on how to manage drug doses in case of AKI in cancer patients. This commentary explores the different options to manage drugs (anticancer drugs, anticoagulants, and other supportive care drugs) during AKI in cancer patients.

Tramadol-paracetamol for postoperative pain after spine surgery - A randomized, double-blind, placebo-controlled study

OBJECTIVES

Multimodal pain management is one component in enhanced recovery after surgery protocol. Here we evaluate the efficacy of tramadol-paracetamol in acute postoperative pain and pain outcome at 12 months after spine surgery in randomized, double-blind, placebo-controlled trial.

METHODS

We randomized 120 patients undergoing spine surgery to receive, for add-on pain management, two tramadol-paracetamol 37.5 mg/325 mg (n = 61) or placebo tablets (n = 59) twice a day for 5 postoperative days. In the hospital, multimodal pain management consisted of dexketoprofen and oxycodone. After discharge, patients were prescribed ibuprofen 200 mg, maximum 1,200 mg/day. Pain, analgesic use, and satisfaction with pain medication were followed up with the Brief Pain Inventory questionnaire before surgery and at 1 and 52 weeks after surgery. The primary outcome was patients' satisfaction with pain medication 1 week after surgery.

RESULTS

At 1 week after surgery, patients' satisfaction with pain medication was similarly high in the two groups, 75% [interquartile range, 30%] in the placebo group and 70% [40%] in the tramadol-paracetamol group (p = 0.949) on a scale: 0% =  not satisfied, 100% = totally satisfied. At 1 week, ibuprofen dose was lower in the placebo group 200 mg [1,000] compared to the tramadol-paracetamol group, 800 mg [1,600] (p = 0.016). There was no difference in the need for rescue oxycodone. Patients in the tramadol-paracetamol group had more adverse events associated with analgesics during the first postoperative week (relative risk = 1.8, 95% confidence interval, 1.2-2.6).

CONCLUSION

Add-on pain treatment with tramadol-paracetamol did not enhance patients' satisfaction with early pain management after back surgery.

Modified Diatomaceous Earth in Heparin Recovery from Porcine Intestinal Mucosa

Heparin, a highly sulfated glycosaminoglycan, is a naturally occurring anticoagulant that plays a vital role in various physiological processes. The remarkable structural complexity of heparin, consisting of repeating disaccharide units, makes it a crucial molecule for the development of commercial drugs in the pharmaceutical industry. Over the past few decades, significant progress has been made in the development of cost-effective adsorbents specifically designed for the adsorption of heparin from porcine intestinal mucosa. This advancement has been driven by the need for efficient and scalable methods to extract heparin from natural sources. In this study, we investigated the use of cationic ammonium-functionalized diatomaceous earth, featuring enhanced porosity, larger surface area, and higher thermal stability, to maximize the isolated heparin recovery. Our results showed that the higher cationic density and less bulky quaternary modified diatomaceous earth (QDADE) could adsorb up to 16.3 mg·g-1 (31%) of heparin from the real mucosa samples. Additionally, we explored the conditions of the adsorbent surface for recovery of the heparin molecule and optimized various factors, such as temperature and pH, to optimize the heparin uptake. This is the introductory account of the implementation of modified diatomaceous earth with quaternary amines for heparin capture.

Simultaneous determination of tramadol and paracetamol in human plasma using LC-MS/MS and application in bioequivalence study of -fixed-dose combination

The study aimed to develop a sensitive and high-throughput liquid chromatography coupled with tandem mass spectrometry method to quantify concentrations of tramadol and paracetamol simultaneously in human plasma. Sample preparation involved single-step protein precipitation using methanol and two deuterated internal standards, tramadol D6 and paracetamol D4. Agilent Poroshell 120 EC-C18 (100 × 2.1 mm, 2.1 µm) analytical column was employed to achieve chromatographic separation. Detection was in positive ion multiple reaction monitoring mode. A tailing factor (Tf) of <1.2, separation factor (K prime) of >1.5 from the column dead time and signal-to-noise (S/N) ratio >10, were obtained for analytes and internal standards. The standard curve was linear over the concentration range of 2.5-500.00 ng/mL for tramadol and 0.025-20.00 μg/mL for paracetamol. A small injection volume of 1 µL, low flow rate of 440 µL/min and short analysis time of 3.5 min reduced the solvent consumption, analysis cost and system contamination. The results of method validation parameters fulfilled the acceptance criteria of bioanalytical guidelines. The method was successfully applied to a bioequivalence study of fixed-dose combination products of tramadol and paracetamol in Malaysian healthy subjects.

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.

10-dehydrogingerdione amends tramadol-elicited neurotransmitters disturbance and apoptosis in the brain of male rats by repleting non-enzymatic antioxidants

Tramadol is analgesic medication to relief acute and chronic pain, referred to as alternative to opioid drugs however its abuse or overdosage may resulted in neuronal toxicity. This is attributed to severe fluctuations of neurotransmitters pattern along with cerebral inflammation and oxidative damage. Present work was undertaken to illustrate the cytoprotective effect of 10-dehydrogingerdione (10-DHGD) on the brain tissues of experimental rats due to Tramadol intake and its underlying mechanism. 24 male wistar rats were randomized into 4 equal groups. Group (1), received tramadol in a dose level 20 mg/kg intrapertioneal (i.p) daily for 30 days and referred to Tramadol group. Group (2), received both of 10-DHGD (10 mg/kg, orally) one hour before tramadol intake (dose as mentioned before) daily for 30 days. Group (3) received 10-DHGD only (10 mg/kg, orally) and daily for 30 days. Group (4), received no drugs and referred to control group for comparison. Tramadol significantly reduced Norepinephrin (NE), dopamine, serotonin and glutathione (reduced) contents of Cerebral cortex. lipid peroxidation, nuclear factor kappa B (NFkB), inducible nitric oxide synthase (INOS) levels and caspase-3 immunoreactivity showed however significant increase. Of note, 10-DHGD significantly increased neurotransmitters, glutathione contents while Malondialdehyde (MDA), Nitric oxide (NO), NFkB, INOS additionally caspase-3 immunoexpression showed significant decrease i.e counteracted to certain extent tramadol effect. These findings may refer to the cytoprotective potential of 10-DHGD against the neurotoxicity exerted by tramadol intake, most probably mediated via enhancement of endogenous antioxidants system.

Subcutaneous versus intravenous tramadol for extremity injury with moderate pain in the emergency department: a randomised controlled noninferiority trial

BACKGROUND AND IMPORTANCE

Musculoskeletal trauma is a common presentation in the emergency department (ED). Tramadol as an analgesic has been recommended by pain management guidelines for musculoskeletal pain. Parenteral tramadol in the ED is commonly administered intravenously. Subcutaneously administered tramadol may have other advantages such as easier and faster preparation, avoids the need for intravenous (i.v.) access, and reduces the incidence of respiratory and gastrointestinal effects. However, studies comparing subcutaneous (s.c.) and i.v. tramadol for the management of acute moderate pain in patients with extremity injury are lacking.

OBJECTIVE

The objective of this study was to compare the clinical efficacy of s.c. tramadol vs. i.v. tramadol in patients with moderate pain due to extremity injury in the ED.

DESIGN, SETTINGS, AND PARTICIPANTS

This non-inferiority randomized controlled trial included adult patients presented to an academic, tertiary hospital ED with moderate pain (pain score of 4-6 on the visual analog scale) due to extremity injury. Intervention patients stratified to pain score were randomized to receive 50 mg of i.v. or s.c. tramadol.

OUTCOMES MEASURE AND ANALYSIS

Primary outcome measure was the difference in the pain score reduction at 30 min after tramadol administration between the two groups. The noninferiority null hypothesis was that the therapeutic difference in terms of pain score reduction of more than 0.8 exists between the two treatment groups at the endpoint.

MAIN RESULTS

In total 232 patients were randomized to i.v. ( n  = 115) or s.c. ( n  = 117). Although 225 were analyzed in the per-protocol population (i.v. = 113; s.c. = 112). The baseline median pain score was 6 (IQR, 5-6). Median pain score reduction at 30 min after administration was 2 (IQR, 1-3) in the IV group vs. 2 (IQR, 1-2) in the s.c. group with a median difference of 0 (IQR, 0-0), which was below the prespecified noninferiority margin of 0.8. Adverse events in the i.v. group were higher compared to the s.c. group (33.6% vs. 8.9%, P  ≤ 0.001).

CONCLUSIONS

The s.c. tramadol is noninferior to i.v. tramadol in the treatment of moderate pain from extremity injuries.

Efficacy of the Erector Spinae Plane Block for Quality of Recovery in Bariatric Surgery: a Randomized Controlled Trial

BACKGROUND

Postoperative pain management after bariatric surgery is difficult due to different physiological properties and high sensitivity toward opioids in patients with obesity. It has been reported that erector spinae plane block (ESPB) contributes to postoperative analgesia when applied together with multimodal analgesia.

METHODS

Eighty patients were randomized either bilateral ESPB (group E) each side or no block (group C). Our primary aim was to evaluate the effects of ESPB on the quality of recovery 24 h postoperatively in bariatric surgery by using 40-item Quality of Recovery-40 (QoR-40) questionnaire. Postoperative pain assessed using a numerical rating scale (NRS), time of additional analgesic requirement, analgesic consumption, side effects, sedation, mobilization time, and postoperative complications were evaluated as secondary outcomes.

RESULTS

Postoperative mean QoR-40 scores were found to be higher in group E (175.02 ± 11.25) than in group C (167.78 ± 18.59) at the postoperative 24th hour (P < 0.05). Pain scores at rest and during movement were higher in group C than in group E. At the postoperative 24th hour, NRS mean SD scores at rest for group C and group E were 3.25 ± 1.32 and 2.40 ± 0.96, respectively. NRS mean SD scores during movement for groups C and E were 3.88 ± 1.49 and 3.12 ± 1.30, respectively. The total amount of tramadol consumed in the first 24 h in group C and group E were mean SD: 86.40 ± 69.60 and 40.00 ± 46.96, respectively; P < 0.05.

CONCLUSIONS

ESPB improved postoperative quality of recovery, reduced NRS scores, and total analgesic consumption in patients with obesity undergoing bariatric surgery.

CLINICAL TRIAL REGISTRATION

NCT05020379.

Evaluation of Pupillometry for CYP2D6 Phenotyping in Children Treated with Tramadol

Following the contraindication of codeine use in children, increasing use of tramadol has been observed in pain management protocols. However, tramadol's pharmacokinetics (PK) and pharmacodynamics are influenced by cytochrome P450 (CYP)2D6 activity, similarly to codeine. Previous studies in adults have demonstrated a correlation between pupillary response and tramadol PK. Our objective was to evaluate pupillometry as a phenotyping method to assess CYP2D6 activity in children treated with tramadol. We included 41 children (mean age 11 years) receiving a first dose of tramadol (2 mg/kg) in the emergency room (ER) as part of their routine care. CYP2D6 phenotyping and genotyping were performed. The concentrations of tramadol and its active metabolite, M1, were measured, and static and dynamic pupillometry was conducted using a handheld pupillometer at the time of tramadol administration and during the ER stay. Pupillometric measurements were obtained for 37 children. Tramadol affected pupillary parameters, with a decrease in pupil diameter in 83.8% of children (p = 0.002) (mean decrease 14.1 ± 16.7%) and a decrease in reflex amplitude constriction in 78.4% (p = 0.011) (mean decrease 17.7 ± 34.5%) at T150 compared to T0. We were unable to identify a correlation between pupillometry measurements and CYP2D6 activity. Likely confounding factors include light intensity, pain, and stress, making the procedure less feasible in paediatric emergency settings.

Tramadol for chronic pain in adults: protocol for a systematic review with meta-analysis and trial sequential analysis of randomised clinical trials

BACKGROUND

Chronic pain in adults is a frequent clinical symptom with a significant impact on patient well-being. Therefore, sufficient pain management is of utmost importance. While tramadol is a commonly used pain medication, the quality of evidence supporting its use has been questioned considering the observed adverse events. Our objective will be to assess the benefits and harms of tramadol compared with placebo or no intervention for chronic pain.

METHODS/DESIGN

We will conduct a systematic review of randomised clinical trials with meta-analysis and trial sequential analysis to assess the beneficial and harmful effects of tramadol in any dose, formulation, or duration. We will accept placebo or no intervention as control interventions. We will include adult participants with any type of chronic pain, including cancer-related pain. We will systematically search the Cochrane Library, MEDLINE, EMBASE, Science Citation Index, and BIOSIS for relevant literature. We will follow the recommendations by Cochrane and the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. The risk of systematic errors ('bias') and random errors ('play of chance') will be assessed. The certainty of evidence will be evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

DISCUSSION

Although tramadol is often being used to manage chronic pain conditions, the beneficial and harmful effects of this intervention are unknown. The present review will systematically assess the current evidence on the benefits and harms of tramadol versus placebo or no intervention to inform clinical practice and future research.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019140334.

The efficacy of prophylactic metoclopramide in preventing nausea and vomiting in patients with acute pain treated with intravenous tramadol: a randomized double-blinded, placebo-controlled trial

OBJECTIVE

To examine the clinical efficacy of prophylactic metoclopramide in reducing the incidence of nausea and vomiting in emergency department (ED) patients with acute pain who were treated with intravenous tramadol.

RESULTS

We conducted a single-center randomized, double-blinded, placebo-controlled trial. A total of 99 ED patients presented with acute pain were recruited. Sixty-four patients were randomized, 31 patients in the treatment arm and 33 in the control arm. Overall, there were no significant differences in baseline characteristics between treatment arm and control arm. Only one patient within each arm reported having nausea symptom. No patients reported vomiting episode. There was no statistically significant difference in the proportion of patients with nausea or vomiting symptoms between the two groups (3.2% in the treatment arm vs. 3.0% in the control arm, p = 1.000). The administration of prophylactic metoclopramide may not provide additional benefit in reducing the occurrence of nausea and/or vomiting episode in ED patients with acute pain treated with intravenous tramadol. Trial registration Randomized clinical trial TCTR20220525001; registration date: 21 October 2021. Retrospectively registered.

Comparison between the effects of epidural lidocaine, tramadol, and lidocaine-tramadol on postoperative pain in cats undergoing elective orchiectomy

BACKGROUND

In veterinary clinical practice, orchiectomy is one of the most common surgical procedures for cats and is performed mainly in young animals. The purpose of this study was to compare three different epidural (EP) analgesic protocols used in cats undergoing orchiectomy in order to determine which protocol resulted in superior outcomes in terms of perioperative analgesia. Twenty-one client-owned male cats were premedicated with a combination of dexmedetomidine (10 µg/kg) and midazolam (0.2 mg/kg) injected intramuscularly. Anesthesia was induced intravenously with propofol. Cats were randomly divided in three treatment groups of seven animals each: Group L received EP lidocaine (2 mg/kg), Group T received EP tramadol (1 mg/kg), and Group LT received EP lidocaine (2 mg/kg) plus tramadol (1 mg/kg). The post-operative pain level was assessed using two different scales: the Glasgow Composite Measure Pain Scale-Feline (CMPS-F) and the Feline Grimace Scale (FGS). Rescue analgesia was administered when the CMPS-F total score was ≥5 or the FGS total score was ≥4.

RESULTS

No adverse effects related to tramadol or lidocaine were observed. Based on post-operative pain assessments, significant differences between groups were observed according to both pain scoring systems. In particular, in Group LT, the CMPS-F and FGS scores decreased significantly in the first six hours following castration.

CONCLUSIONS

Based on our results, EP lidocaine plus tramadol provided the best post-operative analgesic effects in cats submitted to orchiectomy lasting 6 h and could also be a choice to consider for longer surgical procedures.

Comparing ultrasound-guided modified thoracoabdominal nerves block through perichondrial approach with oblique subcostal transversus abdominis plane block for patients undergoing laparoscopic cholecystectomy: a randomized, controlled trial

BACKGROUND

Laparoscopic cholecystectomy(LC) causes significant postoperative pain. Oblique subcostal transversus abdominis plane(OSTAP) block was described for postoperative analgesia, especially for upper abdominal surgeries. Modified thoracoabdominal nerves block through perichondrial approach(M-TAPA) block is a new technique defined by the modification of the thoracoabdominal nerves through perichondrial approach (TAPA) block, in which local anesthetics are delivered only to the underside of the perichondral surface. The primary aim of this study was to evaluate the effect of M-TAPA and OSTAP blocks as part of multimodal analgesia on postoperative opioid consumption in patients undergoing LC.

METHOD

The present study was designed as a randomized, controlled, prospective study. Seventy-six adult patients undergoing LC were randomly assigned to receive either bilaterally M-TAPA or OSTAP block after the induction of anesthesia and before surgery using bupivacaine 0.25%, 25 ml. The primary outcome was assessed as postoperative 24 h opioid consumption, between groups were compared. Secondary outcomes were Numerical Rational scale(NRS) scores, time to first opioid analgesia, patient recovery, using the Quality of Recovery-15 (QoR-15) scale, nausea and vomiting, sedation score, metoclopramide consumption, and evaluating the analgesic range of dermatome.

RESULTS

The mean tramadol consumption at the postoperative 24th hour was higher in the group OSTAP than in group M-TAPA (P = 0.047). NRS movement score at 12th hour was statistically significantly lower in group M-TAPA than in group OSTAP (P = 0.044). Dermatomes showed intense sensory analgesia between T7-11 in both groups, and it was determined that there was proportionally more involvement in the group M-TAPA. There were no differences between the groups in terms of other results.

CONCLUSIONS

After the LC surgery, ultrasound-guided M-TAPA block effectively reduced opioid consumption, postoperative pain, and QoR-15 scores similar to OSTAP block.

CLINICAL TRIAL REGISTRATION

The study was registered prospectively at clinicaltrials.gov (trial ID: NCT05108129 on 4/11/2021).

Critical Appraisal of Current Acute LBP Management and the Role of a Multimodal Analgesia: A Narrative Review

Acute low back pain (LBP) stands as a leading cause of activity limitation and work absenteeism, and its associated healthcare expenditures are expected to become substantial when acute LBP develops into a chronic and even refractory condition. Therefore, early intervention is crucial to prevent progression to chronic pain, for which the management is particularly challenging and the most effective pharmacological therapy is still controversial. Current guideline treatment recommendations vary and are mostly driven by expertise with opinion differing across different interventions. Thus, it is difficult to formulate evidence-based guidance when the relatively few randomized clinical trials have explored the diagnosis and management of LBP while employing different selection criteria, statistical analyses, and outcome measurements. This narrative review aims to provide a critical appraisal of current acute LBP management by discussing the unmet needs and areas of improvement from bench-to-bedside, and proposes multimodal analgesia as the way forward to attain an effective and prolonged pain relief and functional recovery in patients with acute LBP.

CYP24A1 and CYP3A4 Levels, Renal, Hepatic Changes, and Incidence of Oxidative Stress in Tramadol-Alcohol Concomitant Misuse

Introduction Long-term population-based research has demonstrated a link between heavy drinking and the prevalence of kidney disorders; similarly, alcohol abuse has long been recognized as one of the main causes of liver diseases. A recent trend of concomitant use of the opioid analgesic Tramadol and alcohol among young males in sub-Saharan Africa has emerged. Aim and objectives This study's primary aim was to evaluate the incidence of concomitant use of alcohol and Tramadol among adult males, and observe the role of cytochrome p450 3A4 and CYP24A1 proteins and some oxidative stress indicators such as Malondialdehyde, lactate dehydrogenase, among study participants. The secondary aim was to evaluate the effect of alcohol and Tramadol concomitant use on Liver and kidney indices. Methods Our study population was male subjects with a history of Alcohol and Tramadol concomitant use. Liver enzymes, renal indices, oxidative stress markers, and CYP3A4 and CYP24A1 were determined from the serum of test and control participants. IBM Statistical Package for Social Sciences (SPSS) Statistics (version 21.0) was used to analyze the data obtained. Result One hundred and forty-two male subjects were included in this study. Eighty two (82) were males who admitted to abuse of Alcohol and Tramadol concomitantly for at least a year. The dose of Tramadol commonly used by Test subjects was 200 mg (43.9% of the test population), Tramadol users in the study population were largely Undergraduates (75.6% of Test participants). Gamma-glutamyl transferase and lactate dehydrogenase were significantly higher in Test subjects consuming Tramadol and alcohol combination (43.13±1.02 and 117.29±2.45, respectively) versus control (24.87±0.82; p=0.00 and 101.93±1.25; p=0.00). There was a significant decrease in serum bicarbonate levels of Test subjects (16.19±0.53) versus control (22.60±0.68; p=0.000). Cytochrome P450 24A1, was significantly lower in Test subjects (subjects consuming Tramadol and alcohol combination) (0.90±0.06; p=0.01), and significantly threefold higher in subjects with acute myeloid leukemia (AML) (5.16±0.5; p=0.00), when compared with values of non-drug/alcohol users that served as normal control (1.27±0.07). Conclusion The menace of Tramadol and alcohol concomitant abuse has taken a worrisome dimension in sub-Saharan Africa. In this study 77.4% of participants reported euphoria as reason for combining Alcohol and Tramadol, 6.5% claimed it was for faster pain relief and enhanced sexual performance or prolong penile erection was the response of 58.1% of the test participants. Findings of reduced CYP3A4 with Alcohol and Tramadol concomitant use could be associated with delayed drug inactivation and increased drug euphoric action.

Management of Acute Cancer Pain in Asia: An Expert Opinion on the Role of Tramadol/Dexketoprofen Fixed-Dose Combination

Most patients experience acute cancer pain at some stage throughout their cancer journey. When inadequately managed, cancer pain has devastating consequences for the patient's quality of life. The suboptimal management of cancer pain in Asia is mainly driven by over-regulation and limited access to opioids. Concerns about adverse events and addiction have resulted in a negative perception of this group of drugs among physicians, as well as patients. There is a need to optimize the management of cancer pain across the region, through the provision of an alternative treatment option that is simple to prescribe, convenient to administer and well tolerated by patients, which will increase patients' compliance and good results. As recommended in many international guidelines, starting by the WHO analgesic ladder, cancer pain can be effectively managed with multimodal analgesia. Fixed-dose combinations (FDCs), in which two or more analgesic agents act synergistically to deliver a broad spectrum of pain relief, represent an effective and convenient option for delivering multimodal analgesia to patients with cancer pain. This is extremely well accepted by patients for several reasons. Any multimodal pharmacological approach to pain management should be based on the potentiality to block pain at different levels and to reduce the dosages of single analgesics, reducing their side effects. Hence, the use of NSAIDs, combined with other analgesics, is the general basis of multimodal pain management. If NSAIDs are combined with tramadol, a weak opioid that has per se a multimodal analgesic efficacy, it may be ideal. The tramadol/dexketoprofen FDC combines the centrally acting weak opioid with a peripherally acting NSAID to deliver rapid-onset, long-lasting analgesia, which has been proven efficacious and safe in the management of moderate-to-severe acute pain in the postoperative setting. This expert opinion explores the role of tramadol/dexketoprofen FDC in the management of patients with moderate-to-severe acute cancer pain. It is essentially based on the incredibly high amount of existing data on the use of the drug, and on the long-lasting experience of the experts in pain management of cancer patients participating in the advisory panel.

A New Option for Pain Prevention Using a Therapeutic Virtual Reality Solution for Bone Marrow Biopsy (REVEH Trial): Open-Label, Randomized, Multicenter, Phase 3 Study

BACKGROUND

Evidence regarding the analgesic effect of distraction through immersion in virtual reality (VR) for care-induced pain has been documented in several phase 2 trials, but comparison with standard treatments in large, randomized studies is needed.

OBJECTIVE

In this open-label, multicenter, randomized, phase 3 trial, we evaluated the safety and efficacy of a novel VR therapy solution for distraction in the context of bone marrow biopsy.

METHODS

Bliss is a VR software with 4 imaginary interactive environments in 3 dimensions with binaural sound (head-mounted display). Efficacy regarding pain intensity was evaluated using a visual analog scale (VAS; score from 0 to 10) immediately after the biopsy. Secondary end points were anxiety and tolerance. Modified intention-to-treat analysis was performed.

RESULTS

Overall, 126 patients with previously documented untreated or suspected malignant hemopathy between September 6, 2018, and May 18, 2020, were randomly assigned in a 1:1 ratio to receive pain prevention with a mixture of nitrous oxide/oxygen (MEOPA; n=63) or VR (n=63) before and during the bone marrow biopsy. We excluded 8 patients from the final analysis (3 in the MEOPA group and 5 in the VR group). All patients received local anesthesia (lidocaine) before biopsy. Follow-up was limited to 1 month after the biopsy. Participants' median age was 65.5 (range 18-87) years, and 54.2% (64/118) of patients were male. The average pain intensity was 3.5 (SD 2.6, 95% CI -1.6 to 8.6) for the MEOPA group and 3.0 (SD 2.4, 95% CI -1.7 to 7.7) for the VR group, without any significant differences in age, sex, center, and hemopathy (P=.26). Concerning anxiety, 67.5% (79/117; fear of pain questionnaire) of the patients were afraid before the biopsy, and anxiety scores were moderate to very high in 26.3% (30/114; revised Spielberger State-Trait Anxiety Inventory questionnaire) of the patients before the biopsy and 9.0% (10/114) after the biopsy for all patients, without a significant difference between the 2 groups (P=.83). Immersion in VR was well tolerated by the majority (54/57, 95%) of patients in the VR group.

CONCLUSIONS

The intensity of pain did not significantly differ between both arms. VR was well tolerated, and the satisfaction of patients, nurses, and physicians was very high. VR could be an alternative treatment in case of contraindication or intolerance to MEOPA.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03483194; https://clinicaltrials.gov/ct2/show/NCT03483194.

LC-MS/MS and GC/MS Profiling of Petroselinum sativum Hoffm. and Its Topical Application on Burn Wound Healing and Related Analgesic Potential in Rats

Parsley (Petroselinum sativum Hoffm.) is renowned for its ethnomedicinal uses including managing pain, wound, and dermal diseases. We previously highlighted the estrogenic and anti-inflammatory properties of parsley and profiled the phytochemistry of its polyphenolic fraction using HPLC-DAD. To extend our investigation, we here characterized the phytochemical composition of the hydro-ethanolic extract using LC-MS/MS and GC-MS upon silylation, and evaluated the antioxidant, analgesic, antimicrobial, and wound healing activities of its hydro-ethanolic and polyphenolic fraction. The antioxidant property was assessed using FRAP, DPPH, and TAC assays. The antimicrobial activity was tested against four wound infectious microbes (Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans). The analgesic effect was studied using acetic acid (counting the number of writhes) and formalin (recording the licking and biting times) injections while the wound healing activity was evaluated using burn model in vivo. The LC-MS/MS showed that the hydro-ethanolic contains four polyphenols (oleuropein, arbutin, myricetin, and naringin) while GC-MS revealed that it contains 20 compounds including malic acid, D-glucose, and galactofuranoside. The hydro-ethanolic (1000 mg/kg) decreased abdominal writhes (38.96%) and licking time (37.34%). It also elicited a strong antioxidant activity using DPPH method (IC₅₀ = 19.38 ± 0.15 µg/mL). Polyphenols exhibited a good antimicrobial effect (MIC = 3.125-12.5 mg/mL). Moreover, both extracts showed high wound contraction by 97.17% and 94.98%, respectively. This study provides evidence that P. sativum could serve as a source of bio-compounds exhibiting analgesic effect and their promising application in mitigating ROS-related disorders, impeding wound infections, and enhancing burn healing.

Treatment of Pain in Reptiles

This chapter provides an overview of our current understanding of clinical analgesic use in reptiles. Currently, μ-opioid agonist drugs are the standard of care for analgesia in reptiles. Reptile pain is no longer considered a necessary part of recovery to keep the reptile from becoming active too early. Rather, treating pain allows for the reptile to begin normalizing their behavior. This recognition of pain and analgesia certainly benefits our reptile patients and greatly improves reptile welfare, but it also benefits our students and house officers, who will carry the torch and continue to demand excellence in reptile medicine.

Ultrasound-guided bilateral modified-thoracoabdominal nerve block through a perichondrial approach (M-TAPA) in patients undergoing laparoscopic cholecystectomy: a randomized double-blind controlled trial

Background

Modified thoracoabdominal nerve block through the perichondrial approach (M-TAPA) is a new technique that provides effective analgesia of the anterior and lateral thoracoabdominal walls by administering local anesthesia only to the underside of the perichondral surface. The primary purpose of the present study was to investigate the postoperative analgesic efficacy of M-TAPA block performed before surgery in patients undergoing laparoscopic cholecystectomy (LC).

Method

The present study was designed as a double-blind, randomized, controlled, prospective study. A total of 68 patients were included in the study. In group M-TAPA, M-TAPA block was performed bilaterally after the induction of general anesthesia. No block was performed on the group control. The postoperative pain scores, analgesic use in the first 24 h, antiemetic consumption, sedation, postoperative nausea and vomiting (PONV), and Quality of Recovery-40 (QoR-40) scores were recorded.

Results

Pain scores were significantly lower in group M-TAPA than in the group control, both during resting and motion at all times (p < 0.001 at each time point). The total amount of tramadol consumed in the first 24 h was lower in group M-TAPA [median 100 mg, min-max (0-200)] than in the group control (P < 0.001). Postoperative median QoR-40 scores were higher in group M-TAPA compared with the group control (P < 0.001). There were no differences between the groups in terms of other results.

Conclusion

After the LC surgery, ultrasound-guided M-TAPA block reduced postoperative pain scores and tramadol consumption effectively. It was observed that the quality of recovery was also higher because QoR-40 scores were higher.

SeDeM tool-driven full factorial design for osmotic drug delivery of tramadol HCl: Formulation development, physicochemical evaluation, and in-silico PBPK modeling for predictive pharmacokinetic evaluation using GastroPlus™

The study is based on using SeDeM expert system in developing controlled-release tramadol HCl osmotic tablets and its in-silico physiologically based pharmacokinetic (PBPK) modeling for in-vivo pharmacokinetic evaluation. A Quality by Design (QbD) based approach in developing SeDEM-driven full factorial osmotic drug delivery was applied. A 2⁴ Full-factorial design was used to make the trial formulations of tramadol HCl osmotic tablets using NaCl as osmogen, Methocel K4M as rate controlling polymer, and avicel pH 101 as diluent. The preformulation characteristics of formulations (F1-F16) were determined by applying SeDeM Expert Tool. The formulation was optimized followed by in-vivo predictive pharmacokinetic assessment using PBPK “ACAT” model of GastroPlus™. The FTIR results showed no interaction among the ingredients. The index of good compressibility (ICG) values of all trial formulation blends were ≥5, suggesting direct compression is the best-suited method. Formulation F3 and F4 were optimized based on drug release at 2, 10, and 16 h with a zero-order kinetic release (r² = 0.992 and 0.994). The SEM images confirmed micropores formation on the surface of the osmotic tablet after complete drug release. F3 and F4 were also stable (shelf life 29.41 and 23.46 months). The in vivo simulation of the pharmacokinetics of the PBPK in-silico model revealed excellent relative bioavailability of F3 and F4 with reference to tramadol HCl 50 mg IR formulations. The SeDeM expert tool was best utilized to evaluate the compression characteristics of selected formulation excipients and their blends for direct compression method in designing once-daily osmotically controlled-release tramadol HCl tablets. The in-silico GastroPlus™ PBPK modeling provided a thorough pharmacokinetic assessment of the optimized formulation as an alternative to tramadol HCl in vivo studies.

Comparative Histological Study on the Effect of Tramadol Abuse on the Testis of Juvenile and Adult Male Albino Mice

As a synthetic analog of codeine, tramadol is often prescribed to treat mild to moderate pains. This study was designed to estimate and compare the histological effect of tramadol on testes of both juvenile and adult male albino mice. A total number of 40 healthy male albino mice were classified into two main groups as follows: group I (juvenile group, includes 20 mice aged three weeks) subdivided equally into group Ia (control group received isotonic saline) and group Ib (tramadol-treated group received 40 mg/kg/d tramadol orally for 30 days); group II (adult group, includes 20 mice aged two months) subdivided equally into group IIa (control group received isotonic saline) and group IIb (tramadol-treated group). Juvenile and adult tramadol-treated groups showed numerous testicular changes, including blood vessels congestion, widening of intercellular spaces, vacuolization in interstitial tissues, luminal germ cells exfoliation, and increased expression of caspase-3 that indicated cellular apoptosis. In the ultrastructural examination, spermatogenic cells degenerated with the frequent appearance of apoptotic cells. Sertoli cells showed vacuolations, large lipid droplets, and disrupted intercellular cell junctions. These observed testicular changes were markedly observed in the juvenile group. Testicular abnormalities and apoptotic changes can be caused by tramadol administration. These abnormalities are more common in juvenile mice.

Nanobiosensors for detection of opioids: A review of latest advancements

Opioids are generally used as analgesics in pain treatment. Like many drugs, they have side effects when overdosing and causeaddiction problems.Illegal drug use and misuse are becoming a major concern for authorities worldwide; thus, it is critical to have precise procedures for detecting them in confiscated samples, biological fluids, and wastewaters. Routine blood and urine tests are insufficient for highly selective determinations and can cause cross-reactivities. For this purpose, nanomaterial-based biosensors are great tools to determine opioid intakes, continuously monitoring the drugs with high sensitivity and selectivity even at very low sample volumes.Nanobiosensors generally comprise a signal transducer nanostructure in which a biological recognition molecule is immobilized onto its surface. Lately, nanobiosensors have been extensively utilized for the molecular detection of opioids. The usage of novel nanomaterials in biosensing has impressed biosensing studies. Nanomaterials with a large surface area have been used to develop nanobiosensors with shorter reaction times and higher sensitivity than conventional biosensors. Colorimetric and fluorescence sensing methods are two kinds of optical sensor systems based on nanomaterials. Noble metal nanoparticles (NPs), such as silver and gold, are the most frequently applied nanomaterials in colorimetric techniques, owing to their unique optical feature of surface plasmon resonance. Despite the progress of an extensive spectrum of nanobiosensors over the last two decades, the future purpose of low-cost, high-throughput, multiplexed clinical diagnostic lab-on-a-chip instruments has yet to be fulfilled. In this review, a concise overview of opioids (such as tramadol and buprenorphine, oxycodone and fentanyl, methadone and morphine) is provided as well as information on their classification, mechanism of action, routine tests, and new opioid sensing technologies based on various NPs. In order to highlight the trend of nanostructure development in biosensor applications for opioids, recent literature examples with the nanomaterial type, target molecules, and limits of detection are discussed.

Advanced Carbon-Based Polymeric Nanocomposites for Forensic Analysis

Nanotechnology is a powerful tool and fast-growing research area in many novel arenas, ranging from biomedicine to engineering and energy storage. Nanotechnology has great potential to make a significant positive contribution in forensic science, which deals with the identification and investigation of crimes, finding relationships between pieces of evidence and perpetrators. Nano-forensics is related to the development of nanosensors for crime investigations and inspection of terrorist activity by analyzing the presence of illicit drugs, explosives, toxic gases, biological agents, and so forth. In this regard, carbon nanomaterials have huge potential for next-generation nanosensors due to their outstanding properties, including strength combined with flexibility, large specific surface area, high electrical conductivity, and little noise. Moreover, their combination with polymers can provide nanocomposites with novel and enhanced performance owed to synergy between the composite components. This review concisely recapitulates up-to-date advances in the development of polymer composites incorporating carbon-based nanomaterials for forensic science. The properties of the different carbon nanomaterials, several methods used to analyze functional polymeric nanocomposites, and their applications in forensic investigation are discussed. Furthermore, present challenges and forthcoming outlooks on the design of new polymer/carbon nanomaterial composites for crime prevention are highlighted.

Analgesic effects and arthritic changes following tramadol administration in a rat hip osteoarthritis model

We investigated the analgesic effects of tramadol and the arthritic changes following tramadol administration in the rat hip osteoarthritis (OA) model using mono-iodoacetate (MIA). The right hip joints of male Sprague-Dawley rats (n = 5 rats/group) in the Sham group were injected with 25 μl of sterile saline and 1% of fluorogold (FG) retrograde neurotracer. In the MIA + Vehicle and MIA + Tramadol groups, FG and 25 μl of sterile saline with 0.5 mg of MIA were injected into the right hip joint. The MIA + Vehicle and MIA + Tramadol groups were administered daily for 4 weeks, either sterile saline (10 mg/kg, intraperitoneal [i.p.]) or tramadol (10 mg/kg, i.p.). We assessed hyperalgesia every week after MIA administration. Histopathological changes and immunoreactive neurons for calcitonin gene-related peptide (CGRP) in dorsal root ganglia (DRG) were evaluated after 4 weeks of treatment. MIA injection into the hip joint led to mechanical hyperalgesia (p < 0.01), which was significantly reduced by tramadol administration (p < 0.01). Furthermore, daily i.p injection of tramadol significantly suppressed CGRP expression in DRG (p < 0.0001). MIA + Vehicle and MIA + Tramadol groups showed significant cartilage reduction and degeneration compared to the Sham group (p < 0.0001). Interestingly, OA changes significantly progressed in the MIA + Tramadol group compared to the MIA + Vehicle group (p < 0.0001).

Effects of Intravenous Analgesia Using Tramadol on Postoperative Depression State and Sleep Quality in Women Undergoing Abdominal Endoscopic Surgery: A Randomized Controlled Trial

Purpose

This study aimed to explore the effects of intravenous analgesia using tramadol on postoperative depression, anxiety, and sleep in women undergoing abdominal endoscopic surgery.

Patients and Methods

Two hundred female patients (100 in each group) who underwent abdominal endoscopic surgery were recruited to randomly receive intravenous analgesia with sufentanil combined with tramadol (tramadol group) or sufentanil (control group). The primary outcome was the incidence of postoperative depression, which was assessed at 1, 2, and 3 days after surgery using the 13-item Beck Depression Inventory. The secondary outcomes were the incidence of anxiety and sleep quality, which were assessed using the 20-item Self-Rating Anxiety Scale and Richards-Campbell Sleep Questionnaire.

Results

The incidence of depression (Beck depression scale≥4) during the 3-day follow-up in the control group was 51%, which was significantly higher than that in the tramadol group of 28% (relative risk [RR]=0.55; 95% confidence interval [CI], 0.38-0.79; P=0.001). No difference was found in the incidence of anxiety state (Self-Rating Anxiety Scale≥40) between the tramadol and control groups (7%vs 5%; RR=1.40; 95% CI, 0.46-4.25; P=0.552). All of the Richards-Campbell sleep scales of patients in the tramadol group at 1 (77.4±15.2 vs 64.2±20.1, P<0.001), 2 (84.1±14.9 vs 71.8±18.8, P<0.001), and 3 days (87.0±12.2 vs 70.3±21.0, P<0.001) after surgery were higher than those in the control group.

Conclusion

Intravenous analgesia using tramadol can effectively improve the postoperative depression and sleep status of women undergoing abdominal endoscopic surgery. Tramadol is recommended for use in postoperative analgesia when improving postoperative mood, and sleep is needed in clinical practice.

Effects of selective orexin receptor-2 and cannabinoid receptor-1 antagonists on the response of medial prefrontal cortex neurons to tramadol

Tramadol is widely used to control pain in various diseases, but the relevant mechanisms are less known despite the severe risks of abuse. The medial prefrontal cortex (mPFC) is one of the critical centers of the reward system. Studies have shown that orexins and endocannabinoids are likely to play an important role in addiction. In this study, the effect of orexin receptor-2 (OX2R) and endocannabinoid receptor-1 (CB1R) blockade on the neuronal activity of mPFC was investigated in response to tramadol in male rats. Tramadol was injected intraperitoneally, and its effects on the firing of mPFC pyramidal neurons were investigated using in vivo extracellular single-unit recording. Tramadol affected the pyramidal neuronal activity of the mPFC. AM251 (18 nmol/4 μl), as a selective CB1R antagonist, and TCS-OX2-29 (50 nmol/4 μl), as a selective OX2R antagonist, individually or simultaneously were microinjected into the lateral ventricle of the brain (intracerebroventricular, ICV). The results showed that the ratio of neurons with the excitatory/inhibitory or no responses was significantly changed by tramadol (p < .05). These changes were prevented by blockade of CB1Rs alone or blockade of OX2Rs and CB1Rs simultaneously (p < .05). However, blockade of these receptors in the vehicle group had no significant effect on neuronal activity. The findings of this study indicate the potential role of orexin and endocannabinoid systems in mediating the effects of tramadol in mPFC and the possible interaction between the two systems via OX2 and CB1 receptors. However, further studies are needed to identify these effects by examining intracellular signaling.

Opioids and Ocular Surface Pathology; A Literature Review of New Treatments Horizons

This review discusses the role of opioids in the corneal surface and the different pathways and therapeutic methods of management. A literature review was performed using PubMed database. For the database search, the main searching words “opioid” and “topical opioid treatment” were used with the descriptors “cornea”, “ocular surface”, “neuropathic corneal pain”, “corneal sensitivity” and “naltrexone”; original scientific articles and reviews were included to achieve the purpose of the review. The endogenous opioid system has relevant functions in the organism, and in daily use, opioids are used as painkillers. However, these drugs may be employed for other indications as opioid pathways have a wide spectrum. The corneal surface for topical treatment is easily accessible, hence sparing the side effects of systemic opioids. Instillation of opioid antagonist substances, such as naltrexone, increases corneal healing rates and stimulates the division of corneal epithelium cells without deleterious effects. The natural modulation of endogenous opioids controls different forms of pain, including inflammatory and neuropathic pain, both in the ocular surface and in the central nervous system. There are diverse methods in controlling pain using opioids, especially in refractory forms. This review attempts to collect the literature about corneal surface and opioid pathways to provide an overview image and a possible direction of the news treatments.

Efficient Heparin Recovery from Porcine Intestinal Mucosa Using Zeolite Imidazolate Framework-8

Heparin is one of the most valuable active pharmaceutical ingredients, and it is generally isolated from porcine intestinal mucosa. Traditionally, different types of commercial resins are employed as an adsorbent for heparin uptake; however, using new, less expensive adsorbents has attracted more interest in the past few years to enhance the heparin recovery. Zeolite imidazolate framework-8 (ZIF-8), as a metal–organic framework (MOF) with a high surface area, porosity, and good stability at high temperatures, was selected to examine the heparin recovery. In this research, we demonstrate that ZIF-8 can recover up to ~70% (37 mg g⁻¹) of heparin from porcine intestinal mucosa. A mechanistic study through kinetic and thermodynamic models on the adsorption revealed appropriate surface conditions for the adsorption of heparin molecules. The effect of different variables such as pH and temperature on heparin adsorption was also studied to optimize the recovery. This study is the first to investigate the usage of MOFs for heparin uptake.

Preemptive Oral Ketorolac with Local Tramadol Versus Oral Ketorolac in Third Molar Surgery: A Comparative Clinical Trial

Aims

To assess preemptive analgesic efficacy of oral ketorolac with submucous placebo versus oral ketorolac with submucous tramadol during impacted mandibular third molar surgery.

Methodology

A double-blind, split-mouth clinical study was carried on 40 patients having bilateral impacted mandibular third molars. They were divided as group A comprising of 40 patients in whom oral ketorolac with submucous tramadol was administered and group B comprising of 40 patients in whom oral ketorolac with submucous placebo was administered. The study parameters included were pain intensity scores, duration to take 1st rescue analgesia, need of analgesic intake during the first 24 h postoperatively and patient's experience.

Results

The patient's experience was found to be better in the group A as compared to group B while evaluating mean pain intensity scores (VRS, VAS); need of postoperative analgesics and drug-related complications.

Conclusion

Preemptive oral ketorolac with tramadol in comparison to oral ketorolac results in better pain relief, longer pain free intervals with minimum rescue analgesics requirement & lesser postoperative analgesics consumption.

Tramadol Use in Perioperative Care and Current Controversies

PURPOSE OF REVIEW

The aim of this review is to discuss the use of tramadol in the perioperative period. There is no doubt that tramadol has revolutionized pain treatment, making it important to understand the pharmacokinetics and pharmacodynamics in order to provide patients with the safest and most effective analgesia.

RECENT FINDINGS

Tramadol is a centrally acting synthetic analgesic with a multimode of action used to help treat moderate to severe pain. Pharmacologically, the unique opioid acts as a serotonin-norepinephrine reuptake inhibitor, while its metabolite, O-desmethyltramadol, acts on the μ-opioid receptor. The analgesic strength of tramadol is about one-tenth that of morphine, making it a relatively safe analgesic. Potential side effects of tramadol include nausea, vomiting, constipation, pruritus, and respiratory depression; however, the severity of these symptoms is minimal compared to traditional opioids. Although some of the perioperative uses of tramadol may be rare, it is a pain management option to consider when alternatives have proved ineffective.

Population Pharmacokinetic Model for Tramadol and O-desmethyltramadol in Older Patients

BACKGROUND AND OBJECTIVES

Tramadol is commonly prescribed to manage chronic pain in older patients. However, there is a gap in the literature describing the pharmacokinetic parameters for tramadol and its active metabolite (O-desmethyltramadol [ODT]) in this population. The objective of this study was to develop and evaluate a population pharmacokinetic model for tramadol and ODT in older patients.

METHODS

Twenty-one patients who received an extended-release oral tramadol dose (25-100 mg) were recruited. Tramadol and ODT concentrations were determined using a validated liquid chromatography/tandem mass spectrometry method. A population pharmacokinetic model was developed using non-linear mixed-effects modelling. The performance of the model was assessed by visual predictive check.

RESULTS

A two-compartment, first-order absorption model with linear elimination best described the tramadol concentration data. The absorption rate constant was 2.96/h (between-subject variability [BSV] 37.8%), apparent volume of distribution for the central compartment (V₁/F) was 0.373 l (73.8%), apparent volume of distribution for the peripheral compartment (V₂/F) was 0.379 l (97.4%), inter-compartmental clearance (Q) was 0.0426 l/h (2.19%) and apparent clearance (CL/F) was 0.00604 l/h (6.61%). The apparent rate of metabolism of tramadol to ODT (k_t) was 0.0492 l/h (78.5%) and apparent clearance for ODT (CL_m) was 0.143 l/h (21.6%). Identification of Seniors at Risk score (ISAR) and creatinine clearance (CrCL) were the only covariates included in the final model, where a higher value for the ISAR increased the maximum concentration (C_max) of tramadol and reduced the BSV in Q from 4.71 to 2.19%. A higher value of CrCL reduced tramadol C_max and half-life (T_1/2) and reduced the BSV in V₂/F (from 148 to 97.4%) and in CL/F (from 78.9 to 6.61%).

CONCLUSION

Exposure to tramadol increased with increased frailty and reduced CrCL. Prescribers should consider patients frailty status and CrCL to minimise the risk of tramadol toxicity in such cohort of patients.

Transversus Abdominis Plane Block Versus Local Wound Infiltration for Postoperative Pain After Laparoscopic Colorectal Cancer Resection: a Randomized, Double-Blinded Study

BACKGROUND

Despite the extensive administration of the enhanced recovery after surgery (ERAS) program, postoperative pain remains a major concern for patients. Transversus abdominis plane (TAP) block and local wound infiltration (LWI) are two techniques that have been widely applied in abdominal surgery. However, these two techniques have rarely been compared in terms of their analgesic effects on patients that undergo laparoscopic colorectal surgery with the ERAS program.

METHODS

A randomized, double-blinded study was conducted in this study. Briefly, 174 patients that underwent colorectal surgery with the ERAS program were randomly allocated to TAP block treatment (TAP group) or local wound infiltration (LWI group). All patients were assessed for their pain scores at rest and in motion at 6, 24, 48, and 72 h after surgery. The administration frequency of bolus for PCIA and the use amount of rescue analgesics (parecoxib) were recorded. Finally, the patients were monitored with follow-up surveys on their postoperative function recovery, complications, lengths of stay, treatment cost, and satisfaction.

RESULTS

In terms of the pain scores at rest and in motion, the two groups revealed no significant difference throughout the study sessions, and no difference was found in the administration frequency of bolus and the use amount of parecoxib. Moreover, the two groups demonstrated similar results in their postoperative recovery, and no significant differences were found in terms of postoperative complications.

CONCLUSIONS

Compared with local wound infiltration, transversus abdominis plane block is not significantly advantageous for postoperative pain control and recovery in patients undergoing laparoscopic colorectal surgery with the ERAS program. However, local wound infiltration might be preferred since it is available with less technical difficulties.

Comparison of effect of intra socket ketamine and tramadol on postoperative pain after mandibular third molar surgery

Aim:

This study compared the analgesic efficacy of intra socket application of tramadol versus ketamine for preventing pain after mandibular third molar surgery.

Materials and Methods:

Thirty patients who had undergone third molar surgery were randomly divided into three groups: Group T (tramadol 1 mg/kg), Group K (ketamine 0.5 mg/kg), and Group C (saline 2 mL). The treatment was applied to the extraction sockets using resorbable gel foam. Average time taken for the procedure was recorded. Pain was evaluated postoperatively using a visual analog scale (VAS) at 6 and 24 h postoperatively. Furthermore, the number of analgesics taken in the 1^st24 h was recorded. The relevant information was gathered and tabulated. IBM SPSS 2.0 was used to analyze the results and one-way ANOVA test was used to determine the statistical significance.

Results:

The VAS scores after extraction were statistically higher in Group C than in either treatment group. Group K had the lowest pain intensity. During the 1^st6 h, patients reported statistically lower pain intensity scores in Groups K and T versus Group C. At 24 h, Group K had the lowest pain intensity and Group T had less pain than Group C. The number of analgesics taken in the 1^st24 h was highest in Group C.

Conclusion:

This study shows that intra socket use of tramadol and ketamine can be used as effective alternatives for decreasing pain after third molar surgery.

Comparative pharmacokinetics between two tablets of tramadol 37.5 mg/acetaminophen 325 mg and one tablet of tramadol 75 mg/acetaminophen 650 mg for extended-release fixed-dose combination

An extended-release (ER) fixed-dose combination (FDC) of tramadol 37.5 mg/acetaminophen 325 mg was developed due to the demand for varying dosages. This study aimed to evaluate the pharmacokinetics (PKs) for two tablets of the new developed tramadol 37.5 mg/acetaminophen 325 mg ER FDC (DW-0920, Wontran Semi ER^®) as test formulation compared to one tablet of the tramadol 75 mg/acetaminophen 650 mg ER FDC (DW-0919, Wontran ER^®) as reference formulation. A randomized, open-label, 2-way crossover study was conducted in 30 healthy subjects. Subjects were orally administered one of 2 formulations followed by an alternate formulation with a 7-day washout period. Blood samples were collected up to 36 hours post-dose. Plasma concentrations of tramadol and acetaminophen were determined using a validated high-performance liquid chromatography with tandem mass spectrometric method. The geometric mean ratios (GMRs) and their 90% confidence intervals (90% CIs) of test formulation to reference formulation were calculated for the maximum plasma concentration (C_max) and the area under the plasma concentration-time curve from zero to the last measurable time point (AUC_last). The PK profiles of 2 formulations were comparable. The GMRs (90% CI) of C_max and AUC_last for tramadol were 1.086 (1.047–1.127) and 1.008 (0.975–1.042), respectively. The corresponding values for acetaminophen were 0.956 (0.897–1.019) and 0.986 (0.961–1.011), respectively. All the values were within the bioequivalence range of 0.80–1.25. Two tablets of DW-0920 were comparable to one tablet of DW-0919. The DW-0920 may be used for optimal pharmacotherapy for pain control with a lower dose.

Evaluation of mitochondrial dysfunction due to oxidative stress in therapeutic, toxic and lethal concentrations of tramadol

Tramadol (TR) is a centrally acting analgesic drug that is used to relieve pain. The therapeutic (0.1-0.8 mg/l), toxic (1-2 mg/l) and lethal (>2 mg/l) ranges were reported for TR. The present study was designed to evaluate which doses of TR can induce liver mitochondrial toxicity. Mitochondria were isolated from the five rats' liver and were incubated with therapeutic to lethal concentrations (1.7-600 μM) of TR. Biomarkers of oxidative stress including: reactive oxygen species (ROS), lipid peroxidation (LPO), protein carbonyl content, glutathione (GSH) content, mitochondrial function, mitochondrial membrane potential (MMP) and mitochondrial swelling were assessed. Our results showed that ROS and LPO at 100 μM and protein carbonylation at 600 μM concentrations of TR were significantly increased. GSH was decreased specifically at 600 μM concentration. Mitochondrial function, MMP and mitochondrial swelling decreased in isolated rat liver mitochondria after exposure to 100 and 300 μM, respectively. This study suggested that TR at therapeutic and toxic levels by single exposure could not induce mitochondrial toxicity. But, in lethal concentration (≥100 μM), TR induced oxidative damage and mitochondria dysfunction. This study suggested that ROS overproduction by increasing of TR concentration induced mitochondrial dysfunction and caused mitochondrial damage via Complex II and membrane permeability transition pores disorders, MMP collapse and mitochondria swelling.

Comparison of Patient-Controlled Analgesia With Tramadol or Morphine After Video-Assisted Thoracoscopic Surgery in Geriatric Patients

Background

Although video-assisted thoracoscopic surgery (VATS) is a less invasive technique compared to thoracotomy, patients often experience postoperative pain. Hence, intravenous patient-controlled analgesia (PCA) is frequently used. The geriatric age group constitutes a significant portion of patients undergoing thoracic surgery. However, pain management can often be difficult in elderly patients. In this study, we aimed to examine the pain management techniques applied in geriatric patients who underwent VATS and to compare the efficacy and side effects of PCA with morphine and tramadol.

Methodology

The following patients were included in this study: aged 65 years and older, those who underwent elective VATS under general anesthesia, and those who underwent thoracic paravertebral block in the operating room for postoperative pain. We recorded diagnoses, demographic data, American Society of Anesthesiologists status, complications developed during the intraoperative or postoperative 24 hours, postoperative rest and cough Visual Analog Scale (VAS), and need for additional analgesics. The patients were divided into the following two groups: those treated with tramadol PCA (tramadol group) and those treated with morphine PCA (morphine group).

Results

A total of 65 patients were included in this study. Overall, 22 patients were administered tramadol PCA while 43 were administered morphine PCA. There was no statistically significant difference between the groups concerning complications. The 24-hour VAS resting score was statistically significantly lower in patients administered morphine than those administered tramadol (p < 0.05). There was no statistically significant difference between the groups concerning zero-minute, thirty-minute, one-hour, two-hour, six-hour, and twelve-hour VAS resting and cough scores at all times (p > 0.05).

Conclusions

There was no significant difference in the tramadol and morphine groups concerning analgesic efficacy, patient satisfaction, and side effects among geriatric patients who underwent VATS and were administered intravenous PCA. In our view, both tramadol and morphine can be used safely in geriatric patients requiring intravenous PCA. Moreover, because the 24-hour analgesic efficacy was observed to be better in the morphine group in our study, morphine can be preferred in geriatric patients.

A Critical Review of the Pharmacokinetics and Pharmacodynamics of Opioid Medications Used in Avian Patients

Opioid drugs are used to manage moderate to severe pain in mammals and avian species. In dosing opioids for a particular species, it is optimal to use dosing regimens based on pharmacokinetics or pharmacodynamics studies conducted in the same species as variability in the physiology among different species may result in differences in drug pharmacokinetics and pharmacodynamics. Unfortunately, dosing regimens are typically extrapolated from closely related avian species or even mammals, which is unideal. Therefore, this critical review aims to collate and evaluate the dosing regimens of selected opioids: tramadol, hydromorphone, buprenorphine, butorphanol, and fentanyl, in avian species and its related safety, efficacy and pharmacokinetic data. Our review found specific dosing regimens not described in the Exotic Animal Formulary for tramadol used in Indian Peafowl (Pavo cristatus), Muscovy Duck (Cairina moschata) and Hispaniolan Parrot (Amazona ventralis); hydromorphone used in Orange-winged Parrot (Amazona amazonica); buprenorphine used in Cockatiel (Nymphicus hollandicus), American Kestrel (Falco sparverius) and Grey Parrot (Psittacus erithacus); and butorphanol used in Hispaniolan Parrot (Amazona ventralis), Broiler Chicken and Indian Peafowl (Pavo cristatus). Cockatiel appeared to not experience analgesic effects for hydromorphone and buprenorphine, and American Kestrel exhibited sex-dependent responses to opioids. The selected opioids were observed to be generally safe, with adverse effects being dose-dependent.

Analgesic and cardiopulmonary effects of premedication with tramadol in calves anesthetized with the infusion of guaifenesin and thiamylal

This study examined the analgesic and cardiopulmonary effects of intravenous (IV) tramadol during general intravenous anesthesia in calves. Calves were premedicated with diazepam (0.2 mg/kg, IV) with tramadol (2 mg/kg, IV) (group T) or saline (group S). Anesthesia was induced by thiamylal sodium (4 mg/kg, IV) and maintained with an infusion (2 ml/kg/hr) of 5% guaifenesin containing thiamylal sodium (2 mg/ml). Additional thiamylal sodium (1~2 mg/kg, IV) was administered when interference from the calves was observed during surgery. The total counts of additional thiamylal sodium administration, analgesia score using a visual analog scale, recovery time, and cardiopulmonary function in the different groups were assessed and compared. Group T showed significantly fewer counts of additional drug administration and a significantly higher analgesia score. Tramadol may provide adequate analgesia with minimal cardiopulmonary changes in calves during general anesthesia.

Plasma concentrations of tramadol after transdermal application of a single metered dose of a compounded tramadol gel to cats

OBJECTIVE

To determine plasma tramadol concentrations in cats following a single dose of oral and transdermal formulations and the pharmacokinetics for and the concentration of tramadol in the transdermal formulation.

ANIMALS

8 healthy client-owned domestic shorthair cats.

PROCEDURES

1 cat was orally administered 1 dose of tramadol (2 mg/kg), and 7 cats received 1 dose of a proprietary compounded tramadol gel product (median actual dose, 2.8 mg/kg) applied to their inner pinnae. Plasma tramadol concentrations were measured with high-performance liquid chromatography-mass spectrometry at fixed times over 24 hours.

RESULTS

Plasma tramadol concentrations were undetectable or much lower (range, < 1 to 4.3 ng/mL) following application of the transdermal formulation, compared with those following oral administration (maximum plasma tramadol concentration, 261.3 ng/mL [at 4 hours]). Tramadol pharmacokinetics for the transdermal formulation could not be determined. Tramadol concentrations of the transdermal gel product exceeded the estimated label dose in all analyzed gel samples, with concentrations greater than the 90% to 110% United States Pharmacopeia standard for compounded drugs.

CONCLUSIONS AND CLINICAL RELEVANCE

Application of 1 dose of the proprietary transdermal formulation did not yield clinically relevant plasma tramadol concentrations in cats. Although this proprietary formulation is currently available to prescribing veterinarians, it should be used with caution.

Mitochondrial dysfunction and oxidative stress are involved in the mechanism of tramadol-induced renal injury

Tramadol (TMDL) is an opioid analgesic widely administered for the management of moderate to severe pain. On the other hand, TMDL is commonly abused in many countries because of its availability and cheap cost. Renal injury is related to high dose or chronic administration of TMDL. No precise mechanism for TMDL-induced renal damage has been identified so far. The current study aimed to evaluate the potential role of oxidative stress and mitochondrial impairment in the pathogenesis of TMDL-induced renal injury. For this purpose, rats were treated with TMDL (40 and 80 ​mg/kg, i.p, 28 consecutive days). A significant increase in serum Cr and BUN was detected in TMDL groups. On the other hand, TMDL (80 ​mg/kg) caused a substantial increase in urine glucose, ALP, protein, and γ-GT levels. Moreover, urine Cr was significantly decreased in TMDL-treated rats (40 and 80 ​mg/kg). Renal histopathological alterations included inflammation, necrosis, and tubular degeneration in the kidney of TMDL-treated animals. Reactive oxygen species (ROS) formation, increased oxidized glutathione (GSSG), lipid peroxidation, and protein carbonylation was increased, whereas total antioxidant capacity and reduced glutathione levels were considerably decreased in TMDL groups. Significant mitochondrial impairment was also detected in the form of mitochondrial depolarization, adenosine-tri-phosphate (ATP) depletion, mitochondrial permeabilization, lipid peroxidation, and decreased mitochondrial dehydrogenase activity in the kidney of TMDL (80 ​mg/kg)-treated animals. These data suggest mitochondrial impairment and oxidative stress as mechanisms involved in the pathogenesis of TMDL-induced renal injury.