Ketorolac, Oxymorphone, Tapentadol, and Tramadol: A Comprehensive Review

Does Scheduled Low-Dose Short-Term NSAID (Ketorolac) Modulate Cytokine Levels After Orthopaedic Polytrauma? A Secondary Analysis of a Randomized Clinical Trial

OBJECTIVES

To determine whether scheduled low-dose, short-term ketorolac modulates cytokine concentrations in orthopaedic polytrauma patients.

METHODS

DESIGN

Secondary analysis of a double-blinded, randomized controlled trial.

SETTING

Single Level I trauma center from August 2018 to October 2022.

PATIENT SELECTION CRITERIA

Orthopaedic polytrauma patients between 18 and 75 years with a New Injury Severity Score greater than 9 were enrolled. Participants were randomized to receive 15 mg of intravenous ketorolac every 6 hours for up to 5 inpatient days or 2 mL of intravenous saline similarly.

OUTCOME MEASURES AND COMPARISONS

Daily concentrations of prostaglandin E2 and interleukin (IL)-1a, IL-1b, IL-6, and IL-10. Clinical outcomes included hospital and intensive care unit length of stay, pulmonary complications, and acute kidney injury.

RESULTS

Seventy orthopaedic polytrauma patients were enrolled, with 35 participants randomized to the ketorolac group and 35 to the placebo group. The overall IL-10 trend over time was significantly different in the ketorolac group ( P = 0.043). IL-6 was 65.8% higher at enrollment compared to day 3 ( P < 0.001) when aggregated over both groups. There was no significant treatment effect for prostaglandin E2, IL-1a, or IL-1b ( P > 0.05). There were no significant differences in clinical outcomes between groups ( P > 0.05).

CONCLUSIONS

Scheduled low-dose, short-term, intravenous ketorolac was associated with significantly different mean trends in IL-10 concentration in orthopaedic polytrauma patients with no significant differences in prostaglandin E2, IL-1a, IL-1b, or IL-6 levels between groups. The treatment did not have an impact on clinical outcomes of hospital or intensive care unit length of stay, pulmonary complications, or acute kidney injury.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Tramadol and Tapentadol Induce Conditioned Place Preference with a Differential Impact on Rewarding Memory and Incubation of Craving

Tramadol and tapentadol, synthetic opioids commonly prescribed for moderate-to-severe pain, have a unique pharmacology that optimizes their analgesia and safety. However, they are not devoid of risks, presenting addictive, abuse, and dependence potential. While tramadol-reinforcing properties have been documented by various studies with human and animal models, including conditioned place preference (CPP) assays, no similar studies have been performed with tapentadol. In the present study, we performed CPP assays by intraperitoneally administering Wistar rats with a tramadol/tapentadol therapeutic dose. Animal permanence and the number of entries in the CPP compartments were recorded in the preconditioning phase and then 1 (T1), 7 (T7), and 14 (T14) days after conditioning. Both opioids induced a change in place preference (T1), suggesting that they have short-term reinforcing properties. However, only tramadol was associated with place preference retention (T7 and T14), with an increase in the number of entries in the opioid-paired compartment (T1 and T7), showing that it causes rewarding memory and incubation of craving. The results indicate that at therapeutic doses: (1) both drugs cause short-term rewarding effects and (2) as opposed to tramadol, tapentadol does not cause CPP retention, despite its higher central nervous system activity and stricter scheduling.

A Systematic Review and Meta-analysis of Opioids vs Nonopioids in Acute Pancreatitis

Background and Aims

Although abdominal pain is one of the major criteria to diagnose acute pancreatitis (AP), there are no standardized guidelines to treat this troublesome symptom in the hospital setting. The aims of the study are to conduct a meta-analysis and to assess the efficacy of nonopioids vs opioids for pain management in AP.

Methods

We searched the medical literature through May 2021 to identify randomized controlled trials that examined the efficacy of opioids with nonopioids in AP pain management. Efficacy was reported as odds ratio (OR) with 95% confidence intervals (CIs) of each comparison tested.

Results

We identified 7 eligible randomized controlled trials, containing 389 patients. No significant difference in terms of pain intensity at day 1 (OR 0.82, 95% CI -2.55 to 4.19) was found between opioids and nonopioids. Nonopioids have a significantly high risk of supplementary analgesic use compared with opioids (OR 3.87, 95% CI 1.25-12.04). However, this significance is not seen when comparing nonsteroidal anti-inflammatory drugs and paracetamol with opioids (OR 1.67, 95% CI 0.73-3.82) after excluding trials with procaine. Opioids did not show a significant increase in the complications of pancreatitis, nausea and vomiting, sedation, and deaths when compared with nonopioids.

Conclusion

We found nonopioids, especially nonsteroidal anti-inflammatory drugs and paracetamol, can provide adequate pain relief in patients with AP with no change in supplementary analgesic use and adverse events when compared with opioids. Further research is needed to optimize the use of nonopioids along or in combination with opioids for better pain control in patients with AP.

Comparison of intravenous ketorolac at three doses for treating renal colic in the emergency department: A noninferiority randomized controlled trial

BACKGROUND

Ketorolac tromethamine is a nonsteroidal anti-inflammatory drug (NSAID) that is extensively used for the management of renal colic in the emergency department (ED). It has been proposed that ketorolac is used at doses above its analgesic ceiling with no more advantages and increased risk of adverse effects. In this study, we compared the analgesic effects of three doses of intravenous ketorolac in patients with renal colic.

METHODS

This noninferiority, randomized, double-blind clinical trial evaluated the analgesic efficacy of three doses of intravenous ketorolac (10, 20, and 30 mg) in adult patients presenting to the ED with renal colic. Exclusion criteria consisted of age > 65 years, active peptic ulcer disease, acute gastrointestinal hemorrhage, renal or hepatic insufficiency, NSAID hypersensitivity, pregnancy or breastfeeding, unstable vital signs, and patients who had received analgesics in the past 24 hours. Pain was recorded every 15 minutes from baseline up to 60 minutes, and the primary outcome was pain reduction at 30 minutes. If patients still required additional pain medications at 30 minutes, they would receive 0.1 mg/kg intravenous morphine sulfate as a rescue analgesic.

RESULTS

A total of 165 subjects enrolled in this study, 55 in each group. The median visual analog scale score in 30 minutes was improved from 90 at baseline to 40 among subjects who were randomized to 30-mg group. This improvement was 40 and 50 mm in 20- and 10-mg ketorolac treatment arms, respectively, with no significant difference between the three doses (p < 0.05). Secondary outcomes showed similar rescue analgesic administration and adverse effects. There was no serious adverse event.

CONCLUSION

Ketorolac at 10-, 20-, and 30-mg doses can produce similar analgesic efficacy in renal colic.

Evaluation of Abuse and Route of Administration of Extended-Release Tapentadol Among Treatment-Seeking Individuals, as Captured by the Addiction Severity Index-Multimedia Version (ASI-MV)

Background

Tapentadol is a molecule incorporating mu opioid receptor agonism and norepinephrine reuptake inhibition to provide analgesia, with the potential for a lower incidence of gastrointestinal side effects than full mu opioid agonists. Postmarketing surveillance of tapentadol as an active pharmaceutical ingredient has consistently revealed low levels of abuse and diversion.

Objective

The purpose of the present study was to further characterize the abuse liability of tapentadol extended-release (ER) by evaluating the prevalence of past 30-day tapentadol ER abuse and reported routes of administration as compared with ER opioids with Food and Drug Administration (FDA) abuse-deterrent labeling (“ADF opioids”) and ER opioids without FDA abuse-deterrent labeling (“non-ADF opioids”).

Methods

Data were collected from January 2014 through December 2017 from 776 centers located in 43 states throughout the United States using the Addiction Severity Index–Multimedia Version (ASI-MV), an instrument that is integral to the National Addictions Vigilance Intervention and Prevention Program (NAVIPPRO, Inflexxion, an IBH Company, Costa Mesa, CA, USA).

Results

Tapentadol ER had lower rates of past 30-day abuse than ADF ER and non-ADF ER opioid comparators, both at a population level and when adjusted for drug utilization. Tapentadol ER was primarily abused orally, although it was also abused through alternate routes of administration. Cumulative rates of tapentadol ER abuse by alternative routes of administration were lower than both ADF and non-ADF ER opioid comparators, although large confidence intervals resulting from the small sample size of reported tapentadol ER use limit firm conclusions.

Conclusions

In summary, tapentadol ER was found to have lower rates of both past 30-day abuse and use via alternate routes of administration, specifically snorting and smoking, than ADF and non-ADF ER comparators.

Perioperative Pain Management and Opioid Stewardship: A Practical Guide

Surgical procedures are key drivers of pain development and opioid utilization globally. Various organizations have generated guidance on postoperative pain management, enhanced recovery strategies, multimodal analgesic and anesthetic techniques, and postoperative opioid prescribing. Still, comprehensive integration of these recommendations into standard practice at the institutional level remains elusive, and persistent postoperative pain and opioid use pose significant societal burdens. The multitude of guidance publications, many different healthcare providers involved in executing them, evolution of surgical technique, and complexities of perioperative care transitions all represent challenges to process improvement. This review seeks to summarize and integrate key recommendations into a "roadmap" for institutional adoption of perioperative analgesic and opioid optimization strategies. We present a brief review of applicable statistics and definitions as impetus for prioritizing both analgesia and opioid exposure in surgical quality improvement. We then review recommended modalities at each phase of perioperative care. We showcase the value of interprofessional collaboration in implementing and sustaining perioperative performance measures related to pain management and analgesic exposure, including those from the patient perspective. Surgery centers across the globe should adopt an integrated, collaborative approach to the twin goals of optimal pain management and opioid stewardship across the care continuum.

Repeated Administration of Clinically Relevant Doses of the Prescription Opioids Tramadol and Tapentadol Causes Lung, Cardiac, and Brain Toxicity in Wistar Rats

Tramadol and tapentadol, two structurally related synthetic opioid analgesics, are widely prescribed due to the enhanced therapeutic profiles resulting from the synergistic combination between μ-opioid receptor (MOR) activation and monoamine reuptake inhibition. However, the number of adverse reactions has been growing along with their increasing use and misuse. The potential toxicological mechanisms for these drugs are not completely understood, especially for tapentadol, owing to its shorter market history. Therefore, in the present study, we aimed to comparatively assess the putative lung, cardiac, and brain cortex toxicological damage elicited by the repeated exposure to therapeutic doses of both prescription opioids. To this purpose, male Wistar rats were intraperitoneally injected with single daily doses of 10, 25, and 50 mg/kg tramadol or tapentadol, corresponding to a standard analgesic dose, an intermediate dose, and the maximum recommended daily dose, respectively, for 14 consecutive days. Such treatment was found to lead mainly to lipid peroxidation and inflammation in lung and brain cortex tissues, as shown through augmented thiobarbituric acid reactive substances (TBARS), as well as to increased serum inflammation biomarkers, such as C reactive protein (CRP) and tumor necrosis factor-α (TNF-α). Cardiomyocyte integrity was also shown to be affected, since both opioids incremented serum lactate dehydrogenase (LDH) and α-hydroxybutyrate dehydrogenase (α-HBDH) activities, while tapentadol was associated with increased serum creatine kinase muscle brain (CK-MB) isoform activity. In turn, the analysis of metabolic parameters in brain cortex tissue revealed increased lactate concentration upon exposure to both drugs, as well as augmented LDH and creatine kinase (CK) activities following tapentadol treatment. In addition, pneumo- and cardiotoxicity biomarkers were quantified at the gene level, while neurotoxicity biomarkers were quantified both at the gene and protein levels; changes in their expression correlate with the oxidative stress, inflammatory, metabolic, and histopathological changes that were detected. Hematoxylin and eosin (H & E) staining revealed several histopathological alterations, including alveolar collapse and destruction in lung sections, inflammatory infiltrates, altered cardiomyocytes and loss of striation in heart sections, degenerated neurons, and accumulation of glial and microglial cells in brain cortex sections. In turn, Masson's trichrome staining confirmed fibrous tissue deposition in cardiac tissue. Taken as a whole, these results show that the repeated administration of both prescription opioids extends the dose range for which toxicological injury is observed to lower therapeutic doses. They also reinforce previous assumptions that tramadol and tapentadol are not devoid of toxicological risk even at clinical doses.

Paracetamol, ketorolac, and morphine in post-trauma headache in emergency department: A double blind randomized clinical trial

Introduction:

Headache is one of the most common complaints of patients after head trauma. The aim of this study was the comparison of the analgesic effects of intravenous ketorolac, morphine, and paracetamol in patients with headache following head trauma.

Methods:

This clinical trial was performed on 105 referred patients to emergency unit with headache after head trauma. Patients were randomly divided into three groups of intravenous paracetamol (15 mg/kg in 100 mL normal saline), intravenous ketorolac (30 mg/kg in 100 mL normal saline), and intravenous morphine (0.1 mg/kg in 100 mL normal saline). Headache severity and side effects of drugs were assessed at baseline and 15, 30, and 60 min after intervention.

Results:

Headache severity score at baseline was similar among groups. After 15 min, headache severity score in paracetamol group was significantly lower than that in morphine and ketorolac groups (3.7 vs. 4.6 and 4.5, respectively). After 30 min, the score in paracetamol and ketorolac groups was significantly lower than that in morphine group (1.9 and 2.4 vs. 3.2, respectively). After 60 min, headache severity score in three groups was similar (1.6 in morphine and ketorolac groups and 1.5 in paracetamol group). The incidence of side effects in morphine group was significantly more than that in paracetamol and ketorolac groups.

Conclusion:

In emergency department, intravenous paracetamol and ketorolac obtain a faster and more effective onset compared with morphine for headache after head trauma.

Tramadol and the occurrence of seizures: a systematic review and meta-analysis

Introduction: Tramadol is a synthetic opioid which is commonly used around the world to relieve moderate to severe pain. One of the serious possible complications of its use is seizures. The present study aims to investigate and summarize the studies related to tramadol and occurrences of seizures after tramadol use and factors influencing these seizures.Methodology: Our systematic review is compliant with PRISMA guidelines. Two researchers systematically searched PubMed/Medline, Web of Sciences, and Scopus. Cohort, case-control, cross-sectional studies, and clinical trials. The risk of bias was assessed using the Newcastle-Ottawa Scale After article quality assessment, a fixed or random model, as appropriate, was used to pool the results in a meta-analysis. Heterogeneity between the studies was assessed with using I-square and Q-test. Forest plots demonstrating the point and pooled estimates were drawn.Results: A total of 51 articles with total sample size of 101 770 patients were included. The results showed that seizure event rate in the subgroups of tramadol poisoning, therapeutic dosage of tramadol, and tramadol abusers was 38% (95% CI: 27-49%), 3% (95% CI: 2-3%), 37% (95% CI: 12-62%), respectively. Tramadol dose was significantly higher in the patients with seizures than those without (mean differences: 0.82, CI 95%: 0.17-1.46). The odds for occurrence of seizures were significantly associated with male gender (pooled OR: 2.24, CI 95%: 1.80-2.77). Naloxone administration was not associated to the occurrence of seizures (pooled OR: 0.47, 95% CI: 0.15-1.49).Conclusions: Our results demonstrate that the occurrence of seizures in patients exposed to tramadol are dose-dependent and related to male gender, but not related to naloxone administration. Given that, most of the evidence derives from studies utilizing a cross-sectional design, the association of tramadol with seizures should not be considered to be definitively established.

Comparison of efficacy of diclofenac and tramadol in relieving pain in patients of acute pancreatitis: A randomized parallel group double blind active controlled pilot study

BACKGROUND

Opioids and non steroidal anti inflammatory drugs (NSAIDs) are commonly used for pain relief in acute pancreatitis (AP). Opioids carry risk of sphincter of oddi constriction. Although diclofenac prevents post endoscopic retrograde cholangio-pancreatography (ERCP) pancreatitis, few reports of diclofenac associated AP are also present. Although, both tramadol and diclofenac are commonly used for pain relief in AP, no study has evaluated their comparative efficacy and safety.

MATERIALS AND METHODS

Forty-six eligible participants were randomized to either diclofenac or tramadol. Primary objectives of our study were improvement in pain intensity on visual analogue scale (VAS pain score after 1 hr of drug administration) and number of patients requiring supplementary analgesia. The secondary objectives were total number of times of supplementary analgesia requirement, time to significant decrease (33%) in VAS pain score from baseline, number of painful days (VAS pain score >5), VAS pain score on 7th day, side effects, all cause death and complications of pancreatitis between the two groups.

RESULTS

Although 46 patients were randomized, the final analysis included 41 participants. Five patients were withdrawn from the study (intubation = 3, altered sensorium = 2). No significant difference was seen in terms of VAS score after 1 hr of drug administration, number of patients requiring supplementary analgesic and number of painful days. However, time taken to significant reduction of pain was lower in the diclofenac group (p = .028). Both the agents were comparable in terms of safety. Although complications were less in the diclofenac group, the difference was not statistically significant.

CONCLUSION

Both diclofenac and tramadol are equally effective in controlling pain in AP with similar safety profile.

SIGNIFICANCE

There are no studies that have compared the safety and efficacy of two commonly used analgesics for pain relief in patients with AP. We found that both diclofenac and tramadol are equally effective in decreasing the pain associated with AP. There is also no significant difference in the incidence of side effects between both the groups. Hence both diclofenac and tramadol can be used safely and effectively for pain control in AP.

TRIAL REGISTRATION

The trial was registered with clinical trials registry India (Number- CTRI/2018/05/014309).

Pharmacokinetics and Bioequivalence Evaluation of a New Oxycodone Tamper-Resistant Tablet Administered with an Opioid Antagonist in Patients with Chronic Pain

BACKGROUND AND OBJECTIVES

Oxycodone tamper resistant (OTR) is a new extended-release abuse-deterrent formulation providing improvements in the tamper resistant characteristics. This study aimed to investigate the pharmacokinetic properties of the new OTR tablets and evaluate the bioequivalence of oxycodone from OTR and the original extended release (ER) formulation tablets administered with an opioid antagonist in patients with chronic pain.

METHODS

In this open-label, randomized, cross-over study, the enrolled patients were randomised to receive a single dose of 40 mg OTR or 40 mg OXYCONTIN^® (OXY) tablet administered with naltrexone blockade under fasting conditions. Serial blood samples for pharmacokinetic analysis were collected. Plasma oxycodone was quantified by a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method. Tolerability was evaluated by monitoring adverse events, physical examinations, 12-lead ECG and laboratory tests.

RESULTS

A total of 38 patients were enrolled and 33 subjects completed the study. After a single dose of 40 mg tablets, pharmacokinetic results of the new OTR tablet were found to be similar to those of original extended-release oxycodone tablet. OTR 40 mg was bioequivalent to OXY 40 mg and was well tolerated in patients with chronic pain.

CONCLUSIONS

The new OTR formulation could provide a new choice in the treatment of chronic pain and reduce the potential for oxycodone abuse. Chictr.org identifier: ChiCTR1800017253.

Tapentadol vs oxycodone/naloxone in the management of pain after total hip arthroplasty in the fast track setting: an observational study

BACKGROUND

In recent years, joint replacement surgery has gradually progressed towards the fast-track model, and early rehabilitation immediately after surgery is regarded fundamental for optimal recovery of function: the aim of the present study is to describe the efficacy in perioperative management of pain in patients undergoing total hip replacement surgery and treated with tapentadol or oxycodone/naloxone in combination with ketoprofene.

METHODS

Single-center retrospective study on patients with moderate-severe pain, referred to total hip replacement. Patients received either tapentadol (100 mg/twice-daily post-surgery - treatment group) or oxycodone/naloxone (10 mg/5 mg post-surgery - control group) plus ketoprofen 100 mg/ twice daily. Supplemental analgesia (paracetamol 1 g or morphine 0,1 mg/kg sc) was provided if needed. Pain at rest and pain during movement were evaluated on a daily basis for 4 days post-op, after which patients were usually discharged. All adverse events were reported and compared between the two groups.

RESULTS

106 patients were analyzed in the tapentadol group and compared to 105 patients treated with oxycodone/naloxone. Both pain intensity at rest and upon movement were significantly lower in the tapentadol group at all follow-up times (p < 0.001). Throughout T1-T4, supplemental analgesia was needed by significantly less tapentadol patients compared to the control group. Similarly, regarding side effects, a significantly higher occurrence of post-op nausea, vomit, itching and constipation was observed in the control group (p < 0.001 in all cases).

CONCLUSION

Results from the present study support the use of tapentadol in combination with ketoprofen for the management of moderate-severe pain in the setting of major orthopedic surgery, given its effectiveness in reducing pain intensity, and its satisfactory tolerance.

(2S)-N-2-methoxy-2-phenylethyl-6,7-benzomorphan compound (2S-LP2): Discovery of a biased mu/delta opioid receptor agonist

The pivotal role of the stereocenter at the N-substituent of the 6,7-benzomorphan scaffold was investigated combining synthetic and pharmacological approaches. 2R- and 2S-diastereoisomers of the multitarget MOR/DOR antinociceptive ligand LP2 (1) were synthesized and their pharmacological profile was evaluated in in vitro and vivo assays. From our results, 2S-LP2 (5) showed an improved pharmacological profile in comparison to LP2 (1) and 2R-LP2 (4). 2S-LP2 (5) elicited an antinociceptive effect with a 1.5- and 3-times higher potency than LP2 (1) and R-antipode (4), respectively. In vivo effect of 2S-LP2 (5) was consistent with the improved MOR/DOR efficacy profile assessed by radioligand binding assay, to evaluate the opioid receptor affinity, and BRET assay, to evaluate the capability to promote receptor/G-protein and receptor/β-arrestin 2 interaction. 2S-LP2 (5) was able to activate, with different efficacy, G-protein pathway over β-arrestin 2, behaving as biased agonist at MOR and mainly at DOR. Considering the therapeutic potential of both multitarget MOR/DOR agonism and functional selectivity over G-protein, the 2S-LP2 (5) biased multitarget MOR/DOR agonist could provide a safer treatment opportunity.

Comparison of different sufentanil-tramadol combinations for pain relief within the first 24 hours after cesarean section: a retrospective study

Introduction

Postcesarean section pain management is important for both the mother and the newborn. This study compared the analgesic effects and incidence of adverse events associated with intravenous patient-controlled analgesia (iv-PCA), using different sufentanil–tramadol combinations for postoperative pain control.

Methods

Parturients (n=5,794) who had been scheduled for cesarean section under neuraxial anesthesia and had received iv-PCA between September 2013 and March 2017 were retrospectively analyzed. These patients were assigned to three groups, based on different sufentanil–tramadol combinations: ST1 (n=1,347), ST2 (n=2,401), and ST3 (n=2,046). The analgesic efficacy, total drug consumption, and incidence of adverse effects within 24 hours after surgery were compared among the three groups.

Results

The ST3 group had lower visual analog scale pain scores at rest and with movement at all time points during the first 24 hours postoperatively than the other two groups (P<0.01, Bonferroni corrected). The sufentanil dosage administered to the ST3 group was lower, and the tramadol dosage was higher than those administered to the other groups within 24 hours after surgery (P<0.01, Bonferroni corrected). Moreover, all parturients scored 2 points on the Ramsay sedation scale. Adverse reactions such as pruritus and respiratory depression were not observed in any group. No significant differences were noted in the incidence of nausea/vomiting, abdominal distension, and dizziness among the three groups (P>0.05).

Conclusion

The visual analog scale scores for postoperative pain decreased as the concentrations of sufentanil and tramadol administered in iv-PCA moderately increased over 24 hours after surgery. This analgesic strategy resulted in a significant reduction in the total sufentanil requirement without increasing the incidence of adverse effects.

Comparative pharmacology and toxicology of tramadol and tapentadol

Moderate-to-severe pain represents a heavy burden in patients' quality of life, and ultimately in the society and in healthcare costs. The aim of this review was to summarize data on tramadol and tapentadol adverse effects, toxicity, potential advantages and limitations according to the context of clinical use. We compared data on the pharmacological and toxicological profiles of tramadol and tapentadol, after an extensive literature search in the US National Library of Medicine (PubMed). Tramadol is a prodrug that acts through noradrenaline and serotonin reuptake inhibition, with a weak opioid component added by its metabolite O-desmethyltramadol. Tapentadol does not require metabolic activation and acts mainly through noradrenaline reuptake inhibition and has a strong opioid activity. Such features confer tapentadol potential advantages, namely lower serotonergic, dependence and abuse potential, more linear pharmacokinetics, greater gastrointestinal tolerability and applicability in the treatment of chronic and neuropathic pain. Although more studies are needed to provide clear guidance on the opioid of choice, tapentadol shows some advantages, as it does not require CYP450 system activation and has minimal serotonergic effects. In addition, it leads to less side effects and lower abuse liability. However, in vivo and in vitro studies have shown that tramadol and tapentadol cause similar toxicological damage. In this context, it is important to underline that the choice of opioid should be individually balanced and a tailored decision, based on previous experience and on the patient's profile, type of pain and context of treatment.

SIGNIFICANCE

This review underlines the need for a careful prescription of tramadol and tapentadol. Although both are widely prescribed synthetic opioid analgesics, their toxic effects and potential dependence are not completely understood yet. In particular, concerning tapentadol, further research is needed to better assess its toxic effects.

Comparison of ketorolac dosing in an emergency department setting

Clinical question

Does the analgesic effect of intravenous ketorolac differ if given in doses of 10, 15, or 30 mg to patients presenting to the emergency department with acute pain?

Article chosen

Motov S, Yasavolian M, Likourezos A, et al. Comparison of intravenous ketorolac at three single-dose regimens for treating acute pain in the emergency department: a randomized controlled trial. Ann Emerg Med 2017;70(2):177-84.

Phytochemical Analysis and Evaluation of the Antioxidant, Anti-Inflammatory, and Antinociceptive Potential of Phlorotannin-Rich Fractions from Three Mediterranean Brown Seaweeds

Phlorotannins, phenolic compounds produced exclusively by seaweeds, have been reported to possess various pharmacological properties. However, there have been few works on these compounds from Mediterranean seaweeds. In this study, we investigated the phytochemical analysis and pharmacological potential of phlorotannin-rich fractions from three brown seaweeds collected along the Tunisia coast: Cystoseira sedoides (PHT-SED), Cladostephus spongeosis (PHT-CLAD), and Padina pavonica (PHT-PAD). Phytochemical determinations showed considerable differences in total phenolic content (TPC) and phlorotannin content (PHT). The highest TPC level (26.45 mg PGE/g dry material (Dm)) and PHT level (873.14 μg PGE/g Dm) were observed in C. sedoides. The antioxidant properties of these three fractions assessed by three different methods indicated that C. sedoides displayed the highest total antioxidant activity among the three species (71.30 mg GAE/g Dm), as well as the free radical scavenging activity with the lowest IC50 value in both DPPH (27.7 μg/mL) and ABTS (19.1 μg/mL) assays. Furthermore, the pharmacological screening of the anti-inflammatory potential of these fractions using in vivo models, in comparison to reference drugs, established a remarkable activity of PHT-SED at the dose of 100 mg/kg; the inhibition percentages of ear edema in mice model and paw edema in rats model were of 82.55 and 81.08%, respectively. The content of malondialdehyde (MDA) in liver tissues has been quantified, and PHT-SED was found to remarkably increase the lipid peroxidation in rat liver tissues. In addition, in two pain mice models, PHT-SED displayed a profound antinociceptive activity at 100 mg/kg and has proved a better analgesic activity when used in combination with the opioid drug, tramadol.