Tramadol: a review of its use in perioperative pain

Effect of erector spinae plane block on the postoperative quality of recovery after laparoscopic cholecystectomy a prospective double-blind study

BACKGROUND

Laparoscopic cholecystectomy is a common surgical procedure that frequently results in substantial postoperative pain. Erector spinae plane block (ESPB) has been shown to have beneficial postoperative analgesic effects when used as a part of multimodal analgesia. The aim of this study was to determine whether ESPB improves postoperative recovery quality in patients undergoing laparoscopic cholecystectomy. Evaluation of the effects of ESPB on postoperative pain, opioid consumption, and nausea and vomiting was the secondary objective.

METHODS

In this prospective double-blind study, 82 patients undergoing laparoscopic cholecystectomy were randomised into one of two groups: a standard multimodal analgesic regimen in Group N (control) or an ESPB was performed in Group E. Preoperative and postoperative recovery quality was measured using the 40-item quality of recovery (QoR-40) questionnaire; postoperative pain was evaluated using the numerical rating scale scores.

RESULTS

Postoperative mean (standard deviation) QoR-40 scores were higher in Group E (181 [7.3]) than in Group N (167 [11.4]); P<0.01. With repeated measures, a significant effect of group and time was demonstrated for the global QoR-40 score, P<0.01, indicating better quality of recovery in Group E. Pain scores were significantly lower in Group E than in Group N, both during resting and motion at T1-T8 times (P<0.01 at each time). The total amount of tramadol consumed in the first 24 h was lower in Group E [median 0 mg, inter-quartile range (IQR) (0-140)], than in Group N [median 180 mg, IQR (150-240); P<0.01].

CONCLUSIONS

ESPB improved postoperative quality of recovery in patients undergoing laparoscopic cholecystectomy. Moreover, ESPB reduced pain scores and cumulative opioid consumption.

CLINICAL TRIAL REGISTRATION

NCT04112394.

The Expanding Role of the COX Inhibitor/Opioid Receptor Agonist Combination in the Management of Pain

Pain management in both outpatient and inpatient settings demands a multidisciplinary approach entailing medical, physical and psychological therapies. Among these, multimodal analgesic regimens stand out as a promising treatment options. Cyclo-oxygenase (COX) inhibitor/opioid receptor agonist combinations hold great potential as effective pillars in the multimodal pain management by providing adequate analgesia with fewer safety risks due to COX inhibitors’ opioid-sparing effect. Thus, these combinations, either freely or in fixed-dose formulation, offer a feasible option for the prescribing clinicians who seek to maximise therapeutic effect while simultaneously minimise adverse effects. The selection of the appropriate non-steroidal anti-inflammatory drug (NSAID) and opioid agent at optimal doses is essential. It should be tailored to the patients’ analgesic necessities, and his/her gastrointestinal and cardiovascular risk, and potential concurrent aspirin use. Moreover, it should allow for addiction risk and the potential opioid-induced bowel dysfunction and constipation. To ensure an optimal match between the characteristics of the patient and the properties of the chosen medication, and to guide adequate and well-tolerated treatment decisions, it is of paramount importance to expand clinicians’ knowledge of the currently available COX inhibitor/opioid receptor agonist combinations. This invited narrative review deals with the literature evidence covering the components of multimodal opioid-sparing analgesic regimens. Also, it provides insights into the clinically relevant choice criteria to ensure a patient-tailored analgesia.

Tapentadol Versus Tramadol: A Narrative and Comparative Review of Their Pharmacological, Efficacy and Safety Profiles in Adult Patients

We conducted a narrative review of the literature to compare the pharmacological, efficacy and safety profiles of tapentadol and tramadol, and to assess the clinical interest of tapentadol in adult patients. Tapentadol and tramadol share a mixed mechanism of action, including both mu-agonist and monoaminergic properties. Tapentadol is approximately two to three times more potent than tramadol and two to three times less potent than morphine. It has no identified analgesically active metabolite and is not significantly metabolised by cytochrome P450 enzymes, thus overcoming some limitations of tramadol, including the potential for pharmacokinetic drug-drug interactions and interindividual variability due to genetic polymorphisms of cytochrome P450 enzymes. The toxicity profiles of tramadol and tapentadol are similar; however tapentadol is likely to result in less exposure to serotoninergic adverse effects (nausea, vomiting, hypoglycaemia) but cause more opioid adverse effects (constipation, respiratory depression, abuse) than tramadol. The safety of tapentadol in real-world conditions remains poorly documented, particularly in at-risk patient subgroups and also in the ability to assess the risk associated with its residual serotonergic activity (serotonin syndrome, seizures). Because of an earlier market introduction, more real-world safety data are available for tramadol, including data from at-risk patient subgroups. The level of evidence on the efficacy of both tramadol and tapentadol for the treatment of chronic pain is globally low. The trials published to date show overall that tapentadol does not provide a clinically significant analgesic improvement compared to existing treatments, for which the safety profile is much better known. In conclusion, tapentadol is not a first-line opioid but represents an additional analgesic in the therapeutic choices, which some patients may benefit from after careful examination of their clinical situation, co-morbidities and co-medications.

Exploration of Analgesia with Tramadol in the Coxsackievirus B3 Myocarditis Mouse Model

Infection of mice with Coxsackievirus B3 (CVB3) triggers inflammation of the heart and this mouse model is commonly used to investigate underlying mechanisms and therapeutic aspects for viral myocarditis. Virus-triggered cytotoxicity and the activity of infiltrating immune cells contribute to cardiac tissue injury. In addition to cardiac manifestation, CVB3 causes cell death and inflammation in the pancreas. The resulting pancreatitis represents a severe burden and under such experimental conditions, analgesics may be supportive to improve the animals’ well-being. Notably, several known mechanisms exist by which analgesics can interfere with the immune system and thereby compromise the feasibility of the model. We set up a study aiming to improve animal welfare while ensuring model integrity and investigated how tramadol, an opioid, affects virus-induced pathogenicity and immune response in the heart. Tramadol was administered seven days prior to a CVB3 infection in C57BL/6 mice and treatment was continued until the day of analysis. Tramadol had no effect on the virus titer or viral pathogenicity in the heart tissue and the inflammatory response, a hallmark of myocardial injury, was maintained. Our results show that tramadol exerts no disruptive effects on the CVB3 myocarditis mouse model and, therefore, the demonstrated protocol should be considered as a general analgesic strategy for CVB3 infection.

Tramadol-induced hiccups: a case-noncase study in the European pharmacovigilance database

Background

Hiccups are usually benign and self-limiting, but can sometimes be persistent. If left untreated, they can provoke severe discomfort, and even death. Hiccups can be idiopathic, organic, psychogenic, and caused by drugs. Although some case reports have suggested a possible association between tramadol and hiccups, to our knowledge, no study has analyzed this possible relationship. The aim of this study was to analyze whether a disproportionate number of cases of hiccups are reported for tramadol in the EudraVigilance database.

Methods

A case-noncase study was conducted to assess the association between hiccups and tramadol, calculating reporting odds ratios (RORs) from 1 January 1995 to 11 September 2020. Cases were selected using the preferred term 'Hiccups'. The noncases used as controls were all other adverse drug reaction reports recorded in EudraVigilance during the same period. Exposure was defined as exposure to tramadol among cases and noncases. To reduce the risk of confounding by indication, the RORs for tramadol compared with other opioids were obtained. Additionally, we performed a confirmatory analysis in the World Health Organization pharmacovigilance database, VigiBase^®.

Results

There were 3089 cases of hiccups in the 7,213,623 reports. Tramadol was involved in 50 cases. The ROR for tramadol exposure was 3.35 [95% confidence interval (CI) 2.53-4.43]. This association persisted when comparing tramadol with other opioids; ROR: 2.13 (95% CI 1.52-2.99). Disproportionality was also observed in VigiBase^®: ROR 1.69 (95% CI 1.47-1.93).

Conclusion

Our study confirms, for the first time, a possible signal for a tramadol-hiccups association. Nevertheless, observational analytical studies are needed to confirm these results.

Plain Language Summary

Evaluation of the relationship between the tramadol and the risk of hiccupsIntroduction: Hiccups are sudden involuntary contractions of the diaphragm. This involuntary contraction causes the vocal cords to close very briefly, which produces the characteristic sound of a hiccup. Hiccups are usually benign and self-limiting, but can sometimes be persistent. If left untreated, they can provoke severe discomfort, depression, disability, and in the most extreme cases, even death. Drugs are a rare cause of hiccups.Methods: This study investigated the possible association between tramadol and hiccups (an unmentioned adverse drug reaction in the Summary of Product Characteristics) in the European pharmacovigilance database (EudraVigilance) and a confirming analysis in the World Health Organization pharmacovigilance database (VigiBase).Results: Our analysis shows that hiccups is relatively more frequently reported in association with tramadol than with other medicinal products, with EudraVigilance and VigiBase confirming this association.Conclusion: Tramadol is an opioid analgesic indicated, alone or in combination with dexketoprofen or paracetamol for pain with various causes, so healthcare professionals and patients should be aware of this possible association.

Tramadol/Dexketoprofen Analgesic Efficacy Compared with Tramadol/Paracetamol in Moderate to Severe Postoperative Acute Pain: Subgroup Analysis of a Randomized, Double-Blind, Parallel Group Trial-DAVID Study

INTRODUCTION

Recently the DAVID study demonstrated the better analgesic efficacy of tramadol hydrochloride/dexketoprofen 75/25 mg (TRAM/DKP) over tramadol hydrochloride/paracetamol 75/650 mg (TRAM/paracetamol) in a model of moderate to severe acute pain following surgical removal of an impacted third molar. The aim of this subpopulation analysis was to gain a deeper understanding of the relationship between baseline pain intensity (PI) level and the effectiveness in pain control of the TRAM/DKP combination in comparison with the TRAM/paracetamol combination. This will further improve and facilitate the accurate design of future acute pain studies for the use of the TRAM/DKP combination.

METHODS

Patients experiencing at least moderate pain, defined as a PI score ≥ 4 in an 11-point numerical rating scale (NRS) were stratified according to NRS-PI at baseline (NRS ≥ 4, 5, 6, 7, or 8) or aggregated in two groups: (i) moderate pain, NRS-PI ≥ 4 to ≤ 6; (ii) severe pain, NRS-PI > 6. Analgesic efficacy was assessed at pre-specified time points by using pain relief (PAR) on a 5-point verbal rating scale (VRS) and PI on an 11-point NRS. The primary endpoint was total PAR over 6 h post-dose (TOTPAR6); secondary endpoints included, among others, the time course of mean PAR and PI scores over 8 h, TOTPAR over 2, 4, and 8 h post-dose, and the sum of PI difference (SPID) over 2, 4, 6, and 8 h. Safety evaluation was based on the incidence, seriousness, intensity, and causal relationship of treatment-emergent adverse events (TEAEs).

RESULTS

The analgesic efficacy evaluated by TOTPAR6 (primary endpoint) remained steady across increasing baseline PI-NRS cutoff groups with TRAM/DKP, but not with TRAM/paracetamol. The study also demonstrated the superiority of TRAM/DKP combination over TRAM/paracetamol in terms of TOTPAR over 2, 4, and 8 h post-dose and SPID at 2, 4, 6, and 8 h post-dose in both baseline PI groups (moderate or severe); similarly, the time course of PAR and PI indicated better efficacy with TRAM/DKP as soon as 30 min and up to 4-6 h. The incidence of adverse drug reactions was not increased in the severe baseline PI group.

CONCLUSION

Overall, the results of this subgroup analysis of the DAVID study confirmed the superiority of the analgesic efficacy of TRAM/DKP vs TRAM/paracetamol, irrespective of the baseline PI.

Effectiveness of tramadol compared to lignocaine as local anesthesia in the extraction of firm teeth: a randomized controlled trial

Background

The aim of this study was to compare the local anesthetic effect of tramadol with that of lignocaine in the extraction of immobile (grade 0) maxillary first molars.

Methods

This was a randomized, double-blind, equally balanced, controlled trial conducted on a sample population of 116 patients. The patients were randomly divided into two groups: group A (control) and group B (study). Group A and group B participants received 1.8 ml of 2% lignocaine without adrenaline and 1.8 ml of 5% tramadol, respectively through the supra-periosteal infiltration technique before extraction. Intraoperative pain was recorded on the Visual Analog Scale (VAS) and was evaluated using two unpaired t-tests.

Results

Intraoperative pain was evaluated in both the control and study groups. In the control group, the mean VAS score was 0.71 ± 0.81, while in the study group, the mean intraoperative VAS score was 1.21 ± 0.86, with the difference between the two mean values being statistically significant (P = 0.001).

Conclusion

Tramadol has a less potent local anesthetic effect than lignocaine. As a higher dose of tramadol is required to obtain the desired anesthetic effect, it should be used as a supplement to lignocaine in extensive surgical procedures. It can also be used in patients allergic to lignocaine.

A Patient-Controlled Intravenous Analgesia With Tramadol Ameliorates Postpartum Depression in High-Risk Woman After Cesarean Section: A Randomized Controlled Trial

Background: Postpartum depression (PPD) is a severe psychiatric disorder. Its risk is associated with the cesarean section (CS). Currently, there are few early intervention strategies for these women with PPD who underwent CS.

Methods: This was a parallel-group randomized controlled trial of singleton pregnant women who underwent elective CS in a tertiary referral hospital in China from October, 2017 to September, 2019. After operation, patients received randomly tramadol patient-controlled intravenous analgesia (PCIA; 4 mg/ml; TRA group), hydromorphone PCIA (0.04 mg/ml; HYD group), or ropivacaine patient-controlled epidural analgesia (PCEA; 1.5 mg/ml; ROP group) for 48 h in a 1:1:1 ratio. Total blinding during hospitalization was not feasible due to differences between the PCEA and PCIA treatments. All investigators who performed the follow-up were blinded to the group assignment.

Outcomes: A total of 1,230 patients were enrolled for eligibility. Intention-to-treat analysis showed reduced incidence of PPD in the TRA group (n = 27 [6.6%]) than that in the HYD (10.2%, OR 1.62, 95% CI 0.98~2.68; p = 0.059) and ROP groups (10.5%, OR 1.66, 95% CI 1.01~2.75; p = 0.046) at 4 weeks post-operation, however, the difference was not statistically significant (Bonferroni corrected p = 0.118, p = 0.098, respectively). Subgroup analysis in high-risk women (preoperative Edinburgh Postpartum Depression Scale [EPDS] ≥10) showed a significantly lower incidence of PPD in the TRA group (16.5%) than in the HYD (32.6%) and ROP groups (30.9%) (Bonferroni corrected p = 0.022 and p = 0.038, respectively). The per-protocol analysis yielded similar results. Reported adverse events (AEs) were mostly mild. None of the women or infant discontinued treatment due to AEs.

Conclusions: Tramadol PCIA after CS in high-risk women can help to reduce the risk of PPD at 4 weeks after elective CS.

Clinical Trial Registration:https://clinicaltrials.gov/ct2/show/NCT03309163?term=ETPPD&draw=2&rank=1; ClinicalTrials.gov (NCT03309163).

Perioperative Pain Management in Ambulatory and Inpatient Shoulder Surgery

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Acetaminophen is an effective addition to a multimodal pain regimen; however, evidence to support intravenous versus oral administration requires further evaluation.

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While nonsteroidal anti-inflammatory drugs are a valuable addition to a multimodal pain strategy, concerns regarding their effect on healing after certain procedures (i.e., rotator cuff repair) in select patients may preclude their use.

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The use of perioperative gabapentinoids have varied results for pain control, and additional research is warranted to support their use after certain shoulder procedures.

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Opioid-prescribing should be limited and reserved for severe postoperative pain. When prescribed, opioids should be taken at the lowest possible dose and for the shortest period.

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Centrally acting analgesics such as tramadol have been shown to be as effective as opioids and have a lower risk of complications.

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Nerve blocks are an excellent addition to multimodal pain management strategies. Longer-lasting formulations of perioperative single-shot injections and indwelling catheters may reduce rebound pain.

Drug Utilization for Pain Management during Perioperative Period of Total Knee Arthroplasty in China: A Retrospective Research Using Real-World Data

Background and Objective: Total knee arthroplasty (TKA) is one of the most painful procedures and perioperative pain usually requires the use of many analgesics to relieve it. The appropriate use of analgesics to relieve patient pain is an important issue of TKA. To characterize the drug utilization for pain management during perioperative period of TKA in China using real-world data of electronic medical records. Materials and Methods: This research used the data of all inpatients who received TKA at 145 hospitals covered 31 provinces in China from 1 January 2016 to 31 December 2018. The exclusion criteria included pregnancy and cancer diagnosis. In the analysis of drug utilization mode (DUM), medicines were classified into 5 groups: non-steroidal anti-inflammatory drugs (NSAIDs), opioids, non-opioid central analgesics, acetaminophen and others. Results: Among the 2017 patients included in this study, there were 1537 (76.20%) female and 480 (23.80%) male, aged 65.77 ± 7.73 years. Regarding the surgery characteristics, 1658 (82.20%) were unilateral; 1220 (60.49%) was graded Level 4; 1312 (65.05%) used local anesthesia as the main anesthesia method, and 1450 (71.89%) lasted for more than 2 h. The most common DUM was “NSAIDs + opioids” (55.92%), followed by “NSAIDs only” (17.85%), and “NSAIDs + Opioids + Non-opioid central analgesics” (17.15%). The results of the Chi-square test showed that differences in DUM were associated with surgery types, surgery levels, surgery duration, and types of anesthesia used. Up to 81.14% of the total drug expenses for pain management was spent on NSAIDs. Due to the limitation of database, this study could not subdivide operation stages, anesthesia methods, dosage forms of drugs. Conclusion: In China, the use of analgesics in perioperative period of TKA was diversified and influenced by a number of surgery characteristics. The rational use of analgesics should be considered in combination with surgery type, surgery level, surgery duration and anesthesia method.

Influence of Genetic Polymorphisms on the Response to Tramadol, Ibuprofen, and the Combination in Patients With Moderate to Severe Pain After Dental Surgery

PURPOSE

We aimed to elucidate the influence on analgesic effect of genetic polymorphisms in enzymes responsible for biotransformation of tramadol and ibuprofen or other possible genes involved in their mechanism of action.

METHODS

The study population comprised 118 patients from a multicenter, randomized, double-blind, placebo-controlled, Phase III clinical trial that assessed the analgesic efficacy and tolerability of a single dose of ibuprofen (arginine)/tramadol 400/37.5 mg compared with ibuprofen arginine 400 mg alone, tramadol 50 mg alone, and placebo in patients with moderate to severe pain after dental surgery. We analyzed 32 polymorphisms in the cytochrome P450 (CYP) enzymes COMT, ABCB1, SLC22A1, OPRM1, and SLC22A1.

FINDINGS

We did not find any statistically significant difference among CYP2C9 phenotypes related to ibuprofen response, although CYP2C9 poor metabolizers had a longer effect (higher pain relief at 6 hours). Likewise, we did not find any statistically significant difference among PTGS2 genotypes, contradicting previously publications.

IMPLICATIONS

There was not a clear effect of CYP2D6 phenotype on tramadol response, although CYP2D6 poor metabolizers had a slower analgesic effect. Concerning the transport of CYP2D6, we observed a better response in individuals carrying ABCB1 mutated alleles, which might correlate with higher tramadol plasma levels. Finally, we found a statistically significant better response in patients carrying the OPRM1 A118G G allele, which contradicts the previous reports. Measuring the active metabolite O-desmethyl-tramadol formation would be of great importance to better evaluate this association because O-desmethyl-tramadol has a higher μ-opioid receptor affinity compared with the parent drug. EudraCT.ema.europa.eu identifier: 2013-004637-33.

A Case Report of Hypoglycemia Following a Tramadol Overdose in a Non-Diabetic Patient

INTRODUCTION

Tramadol is an opioid analgesic that binds to mu-opioid receptors and inhibits the uptake of norepinephrine and serotonin. Through its activation of these receptors, it has potential to increase the utilization of glucose and/or decrease hepatic gluconeogenesis.

CASE REPORT

A 55-year-old male presents to the Emergency Department (ED) via Emergency Medical Services (EMS) following a self-reported overdose of alprazolam, lorazepam, acetaminophen with codeine, and tramadol. During EMS transport, the patient was found to be hypoglycemic with a glucose of 30 mg/dL and was administered 25 grams of intravenous (IV) dextrose 50% in water. The patient had no past medical history of diabetes mellitus, hypoglycemia, or hyperglycemia and was normoglycemic on his prior presentations to our facility 3 months and 2 years prior. Subsequent analysis found that the patient was negative for acetaminophen, ethanol, salicylates, tricyclics, and lithium. His urinalysis was positive for opiates and benzodiazepines. Upon arrival to the ED, the patient's blood glucose was 131 mg/dL but subsequently dropped to 73 mg/dL, necessitating the initiation of continuous IV fluids containing dextrose. These fluids were discontinued 3.5 hrs later and the patient was discharged 16 days later.

DISCUSSION

This case illustrates that hypoglycemia can be a presenting symptom in patients with an acute overdose of tramadol with no previous history of glycemic dysregulation. Upon presentation it is important to closely monitor serum glucose concentrations to identify hypoglycemia early in order to initiate necessary hypoglycemia protocols.

Tiletamine/zolazepam and dexmedetomidine with tramadol provide effective general anesthesia in rats

Background

Tiletamine/zolazepam is a dissociative anesthetic combination commonly used in small animals but information is limited in rats. The alpha-2 agonist, dexmedetomidine, has gained popularity in laboratory animal anesthesia. Tramadol is a weak opioid mu agonist. The aim of this study was to assess whether the tiletamine/zolazepam/dexmedetomidine (ZD) combination effectively provides a surgical anesthesia plane comparable to tiletamine/zolazepam/dexmedetomidine with tramadol (ZDT) in a minor procedure in rats.

Methods

Rats were induced with ZD or ZDT. After the loss of paw withdrawal, a small incision was made on the rats' left thighs as a surgical stimulus. Rats were maintained under a surgical anesthesia plane by assessing the loss of the paw withdrawal reflex for 45 minutes, then atipamezole was administered. Monitored anesthesia parameters included: (a) physiological parameters - pulse rate (PR), respiratory rate (RR), tissue oxygen saturation (%SpO2), and body temperature; (b) duration parameters - induction time, onset and duration of surgical anesthesia plane, onset of recovery, and recovery time.

Results

PR was significantly lower at 10 minutes in ZD and 5 minutes in ZDT groups. No difference was observed for RR, %SpO2, and body temperature. Likewise, there were no differences for duration parameters: induction time was less than 3 minutes; onset and duration of surgical anesthesia plane were approximately 5 and 45 minutes, respectively; onset of recovery (time to move) was 51 minutes; and recovery time was 52 minutes, respectively.

Conclusion

These data suggest the ZD combination provides a surgical anesthesia plane comparable to ZDT in a rat incisional pain model.

Effect of single dose preoperative intravenous ibuprofen on postoperative pain and opioid consumption: a systematic review and meta-analysis

Background

Ibuprofen, a well-known analgesic, is commonly used as a component of a multimodal analgesic approach for postoperative pain. This systematic review and meta-analysis aimed to investigate whether a single-dose preoperative intravenous ibuprofen can reduce postoperative pain and opioid consumption.

Methods

PubMed/MEDLINE, Embase, Cochrane Library (CENTRAL), and Web of Science databases were searched to identify relevant studies published up to May 2020. Randomized controlled trials comparing preoperative single-dose intravenous ibuprofen effect with the control group on postoperative pain and opioid consumption after surgery under general anesthesia were included.

Results

Six studies involving 366 participants were included. Single-dose administration of intravenous ibuprofen preoperatively significantly reduced postoperative pain score on a scale of 0-10 at 1 h (MD: -1.64, 95% CI [-2.56, -0.72], P < 0.001, I² = 95%), at 4-6 h (MD: -1.17, 95% CI [-2.09, -0.26], P < 0.001, I² = 94%), and 24 h (MD: -0.58, 95% CI [-0.99, -0.18], P < 0.001, I² = 90%). Cumulative opioid consumption, presented as fentanyl equivalents, was also reduced significantly in the ibuprofen group compared to placebo group until postoperative 4-6 h (MD: -56.35 μg, 95% CI [-101.10, -11.60], P < 0.001, I² = 91%) and 24 h (MD: -131.39 μg, 95% CI [-224.56, -38.21], P < 0.001, I² = 95%).

Conclusions

Preoperative single-dose intravenous ibuprofen can reduce postoperative pain and opioid consumption until 24 h postoperatively. Considering the high heterogeneity and small number of studies included, care should be taken when generalizing these findings.

Utilizing multimodal analgesia to evaluate postoperative analgesic requirements in kidney transplant recipients

The use of non-opioid analgesics following surgery has proven beneficial in managing pain and decreasing adverse outcomes following surgery. Data assessing outcomes related to opioid use is limited in kidney transplant recipients (KTRs). We evaluated the effectiveness of implementing a reduced to no opioid use protocol in KTRs. This retrospective cohort study included adult KTRs between January 2017 and July 2019 with a multimodal analgesic protocol (MAP), focused on limiting opioids, implemented in August 2018. We compared analgesic requirements in morphine milligram equivalents (MME) during transplant admissions between the MAP cohort and traditional cohort. There were 217 KTRs who met the criteria. Inpatient opioid use was significantly reduced in the MAP cohort (16.5 ± 19.2 MME/day vs 24.7 ± 19.7 MME/day; P <.05) with no significant difference in pain scores. No use of opioids within six months of discharge was significantly increased in the MAP cohort (50% vs 7%; P <.001), and there were no reported deaths at six months in either cohort. The use of multimodal analgesia is beneficial in KTRs to provide adequate pain control with limited to no exposure of opioids during admission or at discharge.

Intravenous Tramadol is Effective in the Management of Postoperative Pain Following Abdominoplasty: A Three-Arm Randomized Placebo- and Active-Controlled Trial

BACKGROUND AND OBJECTIVE

Oral tramadol, an atypical opioid approved in the United States (US) since 1995 and a Schedule IV controlled substance, has less abuse liability compared to Schedule II conventional opioids. Intravenous (IV) tramadol is not available in the US, but has the potential to fill a gap between non-opioid medications and conventional opioids for treatment of acute pain. This study evaluates IV tramadol in the management of postoperative pain compared to placebo and standard-of-care active control.

METHODS

A phase 3, multicenter, double-blind, three-arm, randomized, placebo- and active-controlled, multiple-dose, parallel-group study was conducted to evaluate the efficacy and safety of 50 mg IV tramadol versus placebo and 4 mg IV morphine over 48 h in patients with postoperative pain following abdominoplasty surgery.

RESULTS

IV tramadol was statistically superior (p < 0.05) to placebo and comparable to IV morphine for the primary and all key secondary efficacy outcomes and demonstrated numerically lower rates for the incidence of most common treatment-emergent adverse events (TEAEs) compared to morphine. No unexpected findings were observed for TEAEs, laboratory tests, vital signs, or electrocardiograms (ECGs). Over 90% of patients completed the study.

CONCLUSION

The study demonstrated that IV tramadol 50 mg is highly effective in the management of postoperative pain following abdominoplasty. The consistency of effects between tramadol and morphine (as compared to placebo) for primary and key secondary endpoints validates the efficacy of tramadol observed. The study also provided direct evidence of improved tolerability of IV tramadol over a standard-of-care conventional Schedule II opioid. IV tramadol may become a useful option in patients where exposure to conventional opioids is not desired.

Continuous-Flow Synthesis of Tramadol from Cyclohexanone

A multioperation, continuous-flow platform for the synthesis of tramadol, ranging from gram to decagram quantities, is described. The platform is segmented into two halves allowing for a single operator to modulate between preparation of the intermediate by Mannich addition or complete the fully concatenated synthesis. All purification operations are incorporated in-line for the Mannich reaction. ‘Flash’ reactivity between meta-methoxyphenyl magnesium bromide and the Mannich product was controlled with a static helical mixer and tested with a combination of flow and batch-based and factorial evaluations. These efforts culminated in a rapid production rate of tramadol (13.7 g°h–1) sustained over 56 reactor volumes. A comparison of process metrics including E-Factor, production rate, and space-time yield are used to contextualize the developed platform with respect to established engineering and synthetic methods for making tramadol.

Tramadol non-medical use in Four European countries: A comparative analysis

BACKGROUND

Understanding prescription medication misuse is challenging due to lack of consistent measures of misuse behaviors and prevalence between countries. Tramadol is an atypical opioid with a dual mechanism, and has low drug liking compared to conventional opioids. We evaluate tramadol misuse compared to conventional opioids utilizing a harmonized validated national survey across four countries: Germany, Italy, Spain, and the United Kingdom (UK).

METHODS

Data from the Survey of Non-Medical Use of Prescription Drugs (NMURx) Program online cross-sectional general population national surveys are analyzed from 2018 from four countries, with 45,000 total responses. Misuse and abuse of tramadol, codeine, morphine, and oxycodone are compared, and national prevalence estimates calculated via calibration weighting. Rates are calculated per population and per drug availability. Supplemental data are included from patients entering treatment centres and poison centre exposures.

RESULTS

In 2018, distribution, misuse, and abuse of four prescription opioids show similar patterns across four countries. In all countries, codeine is misused by the largest number of adults (estimated 861,181 in Italy to 4,676,680 in Spain in past 12 months). When adjusted for availability, tramadol is misused uncommonly with lowest or second lowest rates in all countries. Most abuse occurs by the oral route for all opioids, including tramadol with only 7.27 (Germany) to 54.92 (UK) cases per 100,000 units sold.

CONCLUSIONS

In four countries, tramadol misuse and abuse are infrequent both in absolute number of cases and in comparison to conventional opioids. Even with availability of intravenous tramadol formulations, misuse by injection is rare.

A Screen-Printed Electrode Modified With Graphene/Co3O4 Nanocomposite for Electrochemical Detection of Tramadol

In this paper, graphene (Gr)/Co₃O₄ nanocomposite was synthesized and utilized for the development of a novel electrochemical sensor to detect tramadol. Tramadol determination was examined by linear sweep voltammetry, differential pulse voltammetry, cyclic voltammetry, and chronoamperometry on Gr/Co₃O₄ nanocomposite-modified screen-printed electrode (Gr/Co₃O₄/SPE) in phosphate-buffered saline (PBS). Under the optimized condition, the detection limit of tramadol is 0.03 μM (S/N = 3) in the linear ranges of 0.1–500.0 μM. Furthermore, Gr/Co₃O₄/SPE was satisfactorily utilized to detect tramadol in tramadol tablet and urine specimens.

Determination of the migration effect and molecular docking of verteporfin in different subtypes of breast cancer cells

Breast cancer is one of the most aggressive malignant tumors in women. According to the expression differences of estrogen receptor, progesterone receptor, human epidermal growth factor receptor‑2 (HER‑2) and cell proliferation antigen Ki‑67, breast cancer can be divided into four molecular subtypes: Luminal A, Luminal B, HER‑2 overexpression and Basal‑like. Yes‑associated protein (YAP), a downstream effector of the Hippo pathway, is overexpressed in human cancers and is associated with proliferation, apoptosis, migration, invasion and resistance to chemotherapy drugs in breast cancer cells. Verteporfin (VP) is used as a photosensitizer in the treatment of neovascular macular degeneration. VP is also identified as an inhibitor of YAP/TEA domain transcription factor (TEAD) interaction in the absence of light activation. However, detailed structural information about VP and YAP interactions is relatively scarce and VP research targeting YAP in different molecular subtypes of breast cancer cells is also rare. The aims of the present study were to structurally describe the VP binding site in the YAP crystal structure and to verify the non‑photoreactive VP effect targeting YAP on the migration of different molecular subtypes of breast cancer cells. The crystal structure of VP and YAP was calculated by AutoDock 4.2 and the result was illustrated using PyMOL. The non‑photoactivated VP effect on the migration of Luminal A MCF‑7, Luminal B BT‑474 and triple‑negative breast cancer BT‑549 breast cancer cells was evaluated by wound healing and Transwell migration experiments. Results from molecular docking experiments demonstrated that VP could interact through hydrogen bonds and hydrophobic interactions with important YAP residues involved in TEADs binding (Gln82, Val84, Met86 and Arg89). Migration experiments revealed that the non‑photoinduced VP could inhibit the migration of different molecular subtypes of breast cancer cells. The results of the present study indicated that VP may be a novel repositioned drug for breast cancer treatment in the future.

Perioperative Pregabalin for Preventive Analgesia in Breast Cancer Surgery: A Meta-analysis of Randomized Controlled Trials

OBJECTIVES

Pregabalin is a drug for neuropathic pain. Antipronociceptive properties of pregabalin have led to its recent use as an adjuvant to the multimodal postoperative pain regimen. This meta-analysis was conducted to evaluate the efficacy of perioperative pregabalin on acute and chronic postsurgical pain (CPSP) after breast cancer surgery.

METHODS

A meta-analysis including 8 randomized controlled trials searched from MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials was conducted. Subgroup analysis was performed according to doses and timecourse of pregabalin administration. Review Manager 5.3 was selected to conduct the meta-analysis.

RESULTS

Preoperative pregabalin in breast cancer surgery alleviated acute postoperative pain at rest 24 hours after surgery by 0.31 points on an 0 to 10 Numerical Rating Scale (95% confidence interval [CI] -0.57 to -0.05). Morphine consumption showed a decrease in postoperative use by 1.09 mg (95% CI: -1.61 to -0.57). The incidence of CPSP 3 months after surgery was reduced to 46% (95% CI: 0.25-0.85). Postoperative nausea and vomiting, dizziness, and sedation showed no overall significant reductions. However, a decrease in the incidence of postoperative nausea and vomiting and an increase in the incidence of dizziness were noted when patients received 300 mg of pregabalin before surgery.

DISCUSSION

This study demonstrated that pregabalin showed more efficacy on chronic pain than acute pain after a breast cancer surgery. Further study based on doses and treatment course of pregabalin should be conducted to establish stronger evidence of treatment effects.

Pt-Pd-doped NiO nanoparticle decorated at single-wall carbon nanotubes: An excellent, powerful electrocatalyst for the fabrication of An electrochemical sensor to determine nalbuphine in the presence of tramadol as two opioid analgesic drugs

In this study, a Pt-Pd-doped NiO nanoparticle decorated at the surface of single-wall carbon nanotubes (Pt-Pd/NiO-NPs/SWCNTs) was synthesized using a simple chemical precipitation method and characterized by XRD, TEM, and EDS methods. The results confirmed that Pt-Pd/NiO-NPs/SWCNTs were synthesized with good purity and at the nanoscale size. Moreover, a highly sensitive electroanalytical sensor was fabricated by incorporating synthesized Pt-Pd/NiO-NPs/SWCNT nanocomposites into a carbon paste electrode (CPE) in the presence of 1-ethyl-3-methylimidazolium methanesulfonate (EMICH₃SO₃^-) as binder. The Pt-Pd/NiO-NPs/SWCNTs/EMICH₃SO₃^-/CPE showed a powerful electro-catalytic activity for electro-oxidation of nalbuphine, and the results confirmed that the oxidation of nalbuphine was improved 6.34 times and relative oxidation potential was decreased about 110 mV compared to unmodified electrodes. The Pt-Pd/NiO-NPs/SWCNTs/EMICH₃SO₃^-/CPE also showed good catalytic activity for the determination of nalbuphine in the presence of tramadol and the oxidation potential of these opioid analgesic drugs separated with ΔE =460 mV. In the final step, the Pt-Pd/NiO-NPs/SWCNTs/EMICH₃SO₃^-/CPE was used to determine nalbuphine with a detection limit of 0.9 nM and tramadol with a detection limit of 50.0 nM in drug samples. The results confirmed the powerful and interesting ability of the sensor in the analysis of a real sample.

Tramadol Effects on Lameness Score After Inhibition of P-GP by Ivermectin Administration in Horses: Preliminary Results

This study aimed to evaluate the effects and lameness degree in horses administered tramadol after the P-glycoprotein (P-gp) enteric inhibitor ivermectin. Six horses were randomly distributed into three groups, which received two different doses of tramadol by a nasogastric tube: 1 mg/kg (tramadol group 1(GT1)), 4 mg/kg (tramadol group 4 (GT4)), and tramadol 1 mg/kg combined with ivermectin 0.2 mg/kg PO (ivermectin tramadol group (GT1 + Ive)), with one-week washout interval. Heart rate (HR), respiratory rate (RR), intestinal motility, body temperature, and the degree of lameness were evaluated for 360 minutes. The blood gas parameters were evaluated at 0, 60 minutes, and 120 minutes. There were no differences in HR and the degree of lameness. Hypomotility occurred in GT1 and GT4 only at the end of the evaluation period, and RR increased in all groups. We conclude that inhibition of enteric P-gp by ivermectin did not alter the effects of tramadol, suggesting that tramadol is not a substrate for P-gp. However, future studies should be conducted to assess the interaction between P-gp inhibitors on the pharmacokinetics of tramadol.

Salivary dysfunction caused by medication usage

A considerable number of patients arriving in dental offices are being treated with ongoing medication for a variety of chronic diseases. As a result, dentists must be familiar with the potential side effects these therapeutic agents may have on the tissues of the oral cavity, and in particular on the salivary gland. Salivary gland function may be altered by a wide range of medications, leading to effects such as xerostomia, hyposalivation, hypersalivation or even swelling of the glands. These disorders can cause a variety of other health complications. This review will focus on the most common groups of drugs responsible for salivary gland dysfunction, including psychoactive drugs, antidepressants, antipsychotics, antihypertensives, and antihistamines.

Acute toxicity related to misuse (nonmedical use) of tramadol: Experience of the European Drug Emergencies Network Plus

Following the development of the tramadol crisis currently affecting countries in the Middle East, and Africa, there has been increasing international interest in the regulation of tramadol. This study investigates the misuse of tramadol in patients presenting to emergency departments across Europe. Data from 32 emergency departments in 21 countries were extracted from the Euro-DEN Plus database for the 4-year period from 1 January 2014 to 31 December 2017. Of the reported 24,957 emergency department presentations, tramadol misuse was reported in 105 (0.4% presentations). Tramadol misuse was most common in Bratislava (Slovakia; n = 11, 7.5% of all presentations to this centre), Riga (Latvia; n = 4, 4.9%) and Munich (Germany; n = 17, 2.9%). On arrival, 14 (13.3%) of presentations were in coma/Glasgow coma score ≤ 8 and 9 of these had a respiratory rate <12 breaths/min. These presentations potentially pose a significant burden on emergency departments with a large proportion requiring admission to hospital for ongoing care.

Environmentally relevant levels of four psychoactive compounds vary in their effects on freshwater fish condition: a brain concentration evidence approach

Background

The aquatic environment has been contaminated with various anthropogenic pollutants, including psychoactive compounds that may alter the physiology and behavior of free-living organisms. The present study focused on the condition and related mortality of the juvenile chub (Squalius cephalus). The aim of the study was to test whether the adverse effects of the antidepressants sertraline and citalopram, the analgesic tramadol and the illicit drug methamphetamine, on fish condition exist under environmentally relevant concentrations and whether these effects persist after a depuration period. Innovative analyses of the fish brain concentrations of these compounds were performed with the aim to show relationship between compound brain tissue concentration and fish condition.

Methods

The laboratory experiment consisted of 42 days of exposure and a subsequent 14-day depuration period with regular monitoring of the condition and mortality of exposed and control fish. Identical methodology, including individual brain concentration analyses for the tested compounds, was applied for all substances. Additional study on feeding under sertraline exposure was also conducted. The feeding was measured from the 28th day of the exposure, three times in a week, by observation of food intake during 15 minutes in social environment.

Results

The effects of particular psychoactive compounds on chub condition varied. While sertraline induced a lower condition and increased mortality, the effects of methamphetamine were inverse, and tramadol and citalopram had no significant effect at all. Individual brain concentrations of the tested compounds showed that the effects of sertraline and methamphetamine on fish condition were increased with brain concentration increases. Additionally, the food intake was reduced in case of sertraline. In contrast, there was no relationship between tramadol and citalopram brain tissue concentration and fish condition, suggesting that the concentration-dependent effect is strongly compound-specific. Methamphetamine was the only compound with a persistent effect after the depuration period. Our results demonstrate the suitability of the brain concentration evidence approach and suggest that changes in fish condition and other related parameters can be expected in freshwater ecosystems polluted with specific psychoactive compounds.

ADME and toxicity considerations for tramadol: from basic research to clinical implications

INTRODUCTION

Tramadol is widely being used in chronic pain management for improving patients' life quality and reducing trauma. Although it is listed in several medicinal guidelines, its use is controversial because of the conflicting results obtained in pharmacokinetic/pharmacodynamic studies. This multi-receptor drug acts as µ₁ opioid receptor agonist, monoamine reuptake inhibitor, and inhibitor of ligand-gated ion channels and some special protein-coupled receptors.

AREAS COVERED

This review provides a comprehensive view on the pharmacokinetic, pharmacodynamic, and toxicity of tramadol with a deep look on its side effects, biochemical and pathological changes, and possible drug interactions. In addition, the main ways of tramadol poisoning management describe according to in vivo and clinical trial studies.

EXPERT OPINION

Given the broad spectrum of targets, increasing the cases of overdoses and toxicity, and probable drugs interaction, it is necessary to take another look at the pharmacology of tramadol. Regarding the adverse effects of tramadol on different tissues, especially the nervous system and liver tissue, more attentions to tramadol metabolites, their interaction with other drugs, and active agents seem critical. Seizure as the most cited effect of tramadol and its destructive effects on tissues would alleviate by co-administration with drugs with antioxidant properties.

Involvement of CYP2D6 and CYP2B6 on tramadol pharmacokinetics

This study included 24 healthy volunteers who received a single 37.5 mg oral dose of tramadol. We analyzed 18 polymorphisms within CYP2D6, CYP2B6, CYP3A, COMT, ABCB1, SLC22A1 and OPRM1 genes by quantitative PCR, to study whether these polymorphisms affect its pharmacokinetics, pharmacodynamics and safety. CYP2D6 intermediate metabolizers (n = 6) showed higher tramadol plasma concentrations and lower clearance compared with normal and ultrarapid metabolizers. CYP2B6 G516T T/T (n = 2) genotype was also associated to higher tramadol plasma levels. No other polymorphism affected tramadol pharmacokinetics. Three volunteers experienced a prolonged QTc not associated with the genetic variants studied or altered phamacokinetic parameters. The correlation of CYP2B6 genotype with higher tramadol concentrations is remarkable since its influence on its elimination is also relevant and has been less studied to date. However, given our small sample size, it is important to interpret our results with caution.

Tramadol/Diclofenac Fixed-Dose Combination: A Review of Its Use in Severe Acute Pain

Pain is a health issue affecting all populations, regardless of age, gender, economic status, race, or geography. Acute pain is the most common type of pain, with a complex aetiology. Inadequately managed acute pain adversely affects quality of life and imposes significant economic burden. The majority of the available pain-relieving drugs have monomodal mechanisms of analgesia, which necessitates combining drugs with non-redundant mechanisms of action in order to provide adequate pain relief and reduce the side effects from higher doses of individual drugs. In this regard, combining an oral opioid (such as codeine or tramadol) and a non-opioid (such as paracetamol or non-steroidal anti-inflammatory drug) offers a plausible option. Tramadol/diclofenac fixed-dose combination (FDC) is one such analgesic combination which has demonstrated promising clinical activity via its multimodal mechanisms of action. This review seeks to provide an up-to-date narrative on the current scientific literature regarding the pharmacological properties, clinical efficacy, and tolerability of tramadol/diclofenac FDC in the treatment of acute severe pain. A comprehensive, qualitative review of the literature was conducted using a structured search strategy in Medline/PubMed and additional Internet-based sources to identify relevant studies. Based on the available scientific literature, evidence of the efficacy and safety of tramadol/diclofenac FDC for treatment of patients with acute severe pain, including musculoskeletal pain, postoperative pain, and acute flare-up of osteoarthritis or rheumatoid arthritis, appears to be substantial. Although additional comparative studies would be required to definitively position tramadol/diclofenac FDC with respect to other analgesic combinations, the available data suggest that tramadol/diclofenac FDC is a valuable treatment option for patients with acute severe pain.

A hierarchical 3D camellia-like molybdenum tungsten disulfide architectures for the determination of morphine and tramadol

A practical technique was applied to fabricate MoWS₂ nanocomposite through a one-pot hydrothermal method for use as the electrocatalyst. The characterization of MoWS₂ nanocomposite was investigated by several techniques to identify the size, crystal structure, and elemental composition. MoWS₂ nanocomposite exhibited a unique and well-defined hierarchical structure with neatly and densely piled nanopetals acting as the active sites in the electrocatalytic reactions. A carbon screen-printed electrode (CSPE) modified with interesting MoWS₂ nanopetals (MoWS₂/CSPE) was constructed. Subsequently, the electrochemical oxidation of morphine on fabricated MoWS₂/CSPE was studied. Experimental results confirm that under optimized conditions, the maximum oxidation current of morphine occurs at 275 mV in the case of MoWS₂/CSPE that is around 100 mV more negative than that observed in the case of the unmodified CSPE and about 2.6 times increase was observed for the oxidation peak current. The analytical approach was obtained by differential pulse voltammetry in accordance with the relationship between the oxidation peak current and the morphine concentration. The oxidation peak currents for morphine were found to vary linearly with its concentrations in the range of 4.8 × 10^-8-5.05 × 10^-4 M with the detection limit of 1.44 × 10^-8 M. Two completely separated signals occured at the potentials of 275 mV and 920 mV for oxidation of morphine and tramadol at the surface of MoWS₂/CSPE which are sufficient for determination of morphine in the presence of tramadol. The presence of morphine was also detected in real samples using the introduced approach. Graphical abstract Schematic representation of fabrication of the MoWS₂ nanocomposite through a one-pot hydrothermal method for use as the electrocatalyst. A carbon screen-printed electrode was modified with MoWS₂ nanocomposite. Subsequently, the electrochemical oxidation of morphine on the fabricated electrode was studied.

Long-term stability of an infusion containing paracetamol, alizapride, ketorolac and tramadol in glass bottles at 5±3°C

Background and objective

Infusion containing paracetamol, alizapride, ketorolac and tramadol is used after a general anaesthesia in order to limit pain, fever and nausea. Currently, these infusions are prepared according to demand in the anaesthesia unit, but the preparation in advance could improve quality of preparation and time management. The aim of this study was to investigate the long-term stability of this infusion in glass bottles at 5°C ± 3 °C.

Method

Five bottles of infusion were stored at 5°C ± 3 °C for 60 days. A visual and microscope inspection were performed periodically to observe any particle appearance or colour change. pH and absorbance at three wavelengths were measured. The concentrations were measured by ultra-high performance liquid chromatography - diode array detection.

Results

Multiple verifications were performed during the first 35 days and no crystal, impurity or colour change were observed. At the next time point (42nd day), crystals were visible to the naked eye. pH and absorbance at 350 nm and 550 nm were stable. A slight increase in the absorbance at 410 nm was observed during the study, suggesting that a degradation product could be formed and absorb at this wavelength. The infusion was considered chemically stable while the lower one-sided prediction limit at 95% remains superior to 90% of the initial concentration. Concentration measurements demonstrated that ketorolac and alizapride remained stable in the infusion for 35 days. The stability of tramadol was 28 days. However, degradation of paracetamol was much faster given that concentration has fallen below 90% of the initial concentration after 7 days.

Conclusion

Infusion of paracetamol, alizapride, ketorolac and tramadol remains stable for 7 days in glass bottles at 5°C ± 3 °C and could be prepared in advance with these storage conditions.

Drug utilization review of tramadol hydrochloride in a regional hospital in South Africa; findings and implications

BACKGROUND

Drug utilization reviews (DURs) can be used to promote rational prescribing and ensure compliance with standard treatment guidelines. In recent years, the use of tramadol hydrochloride (HCl) for pain has increased significantly across countries. We sought to determine prescribing patterns and the use of tramadol in a regional hospital in South Africa to provide future guidance in view of increasing concerns with the prescribing of tramadol.

METHOD

A prospective, quantitative and descriptive study was conducted over two months. Outpatient and inpatient prescriptions and ward requisitions where tramadol HCl was prescribed or ordered were identified, which included outpatients collecting antiretroviral treatment. Prescriptions were reviewed and evaluated to determine the level of compliance to the Standard Treatment Guidelines and Essential Medicines List (STGs/EML) for South Africa as a measure of rational prescribing. Quantities issued to the inpatient wards and expenditure incurred by the pharmacy departments were assessed to determine overall usage and total costs.

RESULTS

In total, 415 tramadol HCl prescriptions were collected over a 2-month period. Compliance was 70.1% to the STGs/EML. The outpatient pharmacy department had the highest compliance at 76.4% while the antiretroviral pharmacy compliance was 29.1%. Most prescriptions dispensed at the outpatient pharmacy were from the Surgical Outpatient Department (140; 33.7%) and the Orthopedic Outpatient Department (108; 26.0%). The outpatient pharmacy had the highest tramadol HCl consumption and expenditure at $4,874.13 (R72,054.28), while the inpatient pharmacy's expenditure was $2,526.63 (R37,351.20), and the antiretroviral pharmacy $590.13 (R8,722.75). The hospital's tramadol HCl expenditure increased when compared to previous financial years, from $10,576.04 (R156,326.00) in 2014-2015 to $39,584.00 (R585,088.80) in 2016-2017.

CONCLUSION

This study highlights the need for the implementation of monitoring and evaluation tools to enhance rational prescribing and use of tramadol HCl. These are being implemented and will be evaluated in future projects.

Flurbiprofen axetil for postoperative analgesia in upper abdominal surgery: a randomized, parallel controlled, double-blind, multicenter clinical study

PURPOSE

To investigate the efficacy and safety of flurbiprofen axetil in postoperative analgesia in upper abdominal surgery.

METHODS

This was a multicenter, randomized, positive drug parallel controlled double-blind clinical study. Patients undergoing upper abdominal surgery were randomly divided to receive flurbiprofen axetil or tramadol. The VAS pain scores at rest and on coughing (pulmonary function training) were assessed immediately before drug usage (T1) to evaluate the efficacy of postoperative analgesia. Repeat assessment of the VAS was performed after T1. The timing of the recovery of the gastrointestinal function and the preoperative and postoperative IL-6, cortisol, and blood glucose levels were recorded as secondary endpoints. Vital signs and the occurrence of adverse reactions were evaluated for the assessment of safety.

RESULTS

A total of 240 patients were enrolled in the current study; 119 used flurbiprofen axetil for postoperative analgesia. The VAS scores at rest and on coughing did not differ between the two groups to a statistically significant extent (P > 0.05). However, the reduction of the VAS score at rest in the flurbiprofen axetil group was greater than that in the tramadol group at 4-24 h after T1. The reduction of the VAS score on coughing at 8 h after T1 was greater in the flurbiprofen axetil group. The incidence of adverse reactions was significantly lower in the flurbiprofen axetil group, with only one adverse reaction recorded. In contrast, 18 adverse reactions were reported in the tramadol group.

CONCLUSION

Flurbiprofen axetil showed superior efficacy to tramadol in early postoperative analgesia after upper abdominal surgery. Flurbiprofen axetil was associated with a significantly lower incidence of adverse reactions in comparison to tramadol.

Analgesic Efficacy of Tramadol Compared With Meloxicam in Ducks (Cairina moschata domestica) Evaluated by Ground-Reactive Forces

The purpose of this study was to determine the efficacy of tramadol and meloxicam in an induced, temporary arthritis model in ducks as assessed by ground-reactive forces measured by a pressure-sensitive walkway (PSW) system. Twelve ducks (Cairina moschata domestica) were randomly separated into 3 equal groups of 4 birds each: water control, tramadol treatment, and meloxicam treatment. Baseline measurements were collected by having all ducks walk along a 3-m-long PSW in a custom-built corral before anesthesia and induction of arthritis. Arthritis was induced in all groups through injection, under anesthesia, of a 3% monosodium urate (MSU) solution into the intertarsal joint. One hour after MSU injection, birds were orally gavage fed 1 mL of tap water (control), tramadol (30 mg/kg), or meloxicam (1 mg/kg). After treatments, all ducks were reevaluated on the PSW at 1, 2, 3, 4, 8, and 24 hours post-MSU injection. The difference in maximum force was significantly greater in the control group than in both the tramadol- (P = .006) and meloxicam-treated (P = .03) individuals. Post hoc comparisons revealed differences between control and treated birds occurred only at the 3- and 4-hour time points after administration. No differences were found in the absolute difference in maximum force between tramadol- and meloxicam-treated birds at any time point (P > .05). Results of this study support the hypothesis that tramadol (30 mg/kg PO) and meloxicam (1 mg/kg PO) improve certain objective variables in an induced arthritis model in ducks. Our findings also support studies in other avian species that determined that both tramadol and meloxicam are effective analgesic drugs in some birds.

Capillary Electrophoresis Methods for the Determination of Tramadol: A Review

Tramadol is a widely used opioid analgesic frequently prescribed for treatment of moderate to severe, acute and chronic pain. It has a complex mechanism of action, acting both as a central opiate agonist and as a norepinephrine and serotonin reuptake inhibitor. It is a chiral substance, having two chiral centers in its structure and it is used in therapy as a racemic mixture of two of its enantiomers, (S,S)-tramadol and (R,R)-tramadol. In the last 25 years, several analytical procedures have been published in the literature for the achiral and chiral determination of tramadol from pharmaceutical formulations and biological matrices. Among these methods, capillary electrophoresis techniques have proved to be an efficient, reliable and cost-effective solution. The purpose of the present review is to provide a systematic survey to present and discuss the electrodriven methods available in the literature for the achiral and chiral analysis of tramadol.

Comparing the Pharmacokinetics of 2 Novel Intravenous Tramadol Dosing Regimens to Oral Tramadol: A Randomized 3-Arm Crossover Study

Tramadol is a dual-mechanism (opiate and monoamine reuptake inhibition) analgesic. Intravenous (IV) tramadol has been widely prescribed outside the United States. However, there have not been studies comparing the pharmacokinetics (PK) of IV dosing regimens to that of oral tramadol. In this phase 1, open-label, single investigational center, 3-treatment, 3-period, multidose crossover study, we compared 2 novel IV dosing regimens (IV tramadol 75 mg and IV tramadol 50 mg) to oral tramadol 100 mg given every 6 hours (the highest approved oral dosage in the United States) Compared to the oral regimen, IV tramadol 50 mg administered at hours 0, 2, and 4 and every 4 hours thereafter reached initial tramadol peak serum concentration (C_max ) more rapidly, while resulting in similar overall steady-state C_max and area under the plasma concentration-time curve. IV tramadol 75 mg administered at hours 0, 3, and 6 and every 6 hours thereafter had higher C_max and greater fluctuation in peak to trough tramadol concentration. The primary metabolite M1 (a potent μ agonist) had lower area under the plasma concentration-time curve and C_max for both IV regimens than for the oral regimen. IV tramadol at both doses was well tolerated, with adverse event profiles consistent with the known pharmacological effects of tramadol. IV tramadol 50 mg is now in phase 3 development in patients with postsurgical pain.

Use of Tramadol for Management of Opioid Use Disorders: Rationale and Recommendations

Opioids are one of the most common illicit psychoactive substances being used in India. In fact, opioid use disorders are the most common disorder presenting to the substance use disorder treatment centers across the country. Effective and evidence-based interventions are available for management of opioid use disorders. However, the treatment for opioid use disorders remains difficult to access for most of those in need in India. The current article presents the literature on the use of tramadol for the management of opioid use disorders. It also makes recommendations on the use of tramadol for the management of opioid use disorders. Tramadol offers a viable alternative to the existing options for the management of opioid use disorders. It has been found effective when used for this indication. It offers certain major advantages such as easy and wide availability and low abuse liability. It offers a good option to expand the treatment services for opioid use disorders across the country.

Effect of Tramadol Pretreatment on Sufentanil-Induced Cough

PURPOSE

To investigate the effect of tramadol pretreatment on the incidence and severity of sufentanil-induced cough.

DESIGN

Randomized controlled trial.

METHODS

Adults of both genders (N = 304; 18 to 65 years old, American Society of Anesthesiologists physical status I to II), scheduled for elective surgery, were randomized into two groups (n = 152): intravenous administration of tramadol 1 mg/kg (group T) or normal saline (group C). Then sufentanil bolus 0.3 mcg/kg was administered intravenously in 5 seconds. The incidence and severity of cough were observed for 1 minute. Mean arterial pressure, heart rate, nausea, vomiting, and truncal rigidity during induction were also recorded.

FINDINGS

Patient characteristics were similar between the two groups. The incidence of cough was significantly lower in group T when compared with group C (7.9% vs 18.4%, P < .05); there were nine patients coughing severely in group C, whereas no severe cough occurred in group T (P < .05). The mean arterial pressure, heart rate, and incidences of other side effects were comparable between the two groups.

CONCLUSIONS

Pretreatment of intravenous tramadol 1 mg/kg could be a clinically effective intervention for attenuating sufentanil-induced cough.

Revisiting Tramadol: A Multi-Modal Agent for Pain Management

Tramadol-an atypical opioid analgesic-has a unique pharmacokinetic and pharmacodynamic profile, with opioidergic, noradrenergic, and serotonergic actions. Tramadol has long been used as a well-tolerated alternative to other drugs in moderate pain because of its opioidergic and monoaminergic activities. However, cumulative evidence has been gathered over the last few years that supports other likely mechanisms and uses of tramadol in pain management. Tramadol has modulatory effects on several mediators involved in pain signaling, such as voltage-gated sodium ion channels, transient receptor potential V1 channels, glutamate receptors, α₂-adrenoceptors, adenosine receptors, and mechanisms involving substance P, calcitonin gene-related peptide, prostaglandin E₂, and proinflammatory cytokines. Tramadol also modifies the crosstalk between neuronal and non-neuronal cells in peripheral and central sites. Through these molecular effects, tramadol could modulate peripheral and central neuronal hyperexcitability. Given the broad spectrum of molecular targets, tramadol as a unimodal analgesic relieves a broad range of pain types, such as postoperative, low back, and neuropathic pain and that associated with labor, osteoarthritis, fibromyalgia, and cancer. Moreover, tramadol has anxiolytic, antidepressant, and anti-shivering activities that could improve pain management outcomes. The aim of this review was to address these issues in the context of maladaptive physiological and psychological processes that are associated with different pain types.

The analgesic interaction of tramadol and morphine in rats: An isobolographic study

In order to assess possible synergistic antinociceptive interactions, the analgesic effects of intra-peritoneal tramadol and morphine administered either separately or in combination were determined using tail-flick latency test following exposure to radiant heat in rats. Groups of eight male Sprague-Dawley rats received either tramadol (3.90, 7.00, 12.50, and 22.20 mg kg^-1) and morphine (1.26, 2.25, 4.00 and 7.10 mg kg^-1) or a combination of tramadol and morphine (4 different combinations). The baseline latency was obtained before drug injection for each rat, then at 15, 30, 45, 60 and 75 min after injection. The effective dose (ED)₅₀ for either tramadol or morphine individually was 11.70 mgkg^-1 and 2.26 mg kg^-1, respectively. Based on isobolographic analysis, the ED₅₀ values obtained by drug combination were significantly less than the calculated additive values; which indicates that the co-administration of tramadol and morphine produces synergistic antinociception in the radiant heat tail-flick assay. Combination of morphine and tramadol administered intra-peritoneally can be used for the control of acute pain in rats.

Effect of Premedication on the Success of Inferior Alveolar Nerve Block in Patients with Irreversible Pulpitis: A Systematic Review of the Literature

Background

Failure in the provision of inferior alveolar nerve block anesthesia (IANB) is a significant problem during endodontic treatment of irreversible pulpitis. Various methodologies have been advocated one of which is administration of premedication prior to anesthesia. Despite the considerable number of reports, the topic yet deserves more clarification. This systematic review was conducted to provide an oversight on the effectiveness of premedication prior to IANB in mandibular teeth.

Methods

A PubMed and Cochrane Database search was conducted by using MeSH terms inferior alveolar nerve block + pulpitis and mandibular anesthesia+pulpitis. Two reviewers independently performed the screening, selection of papers, and data extraction. Papers in English language that included randomized clinical studies on the impact of different medications on the success of inferior alveolar block anesthesia in irreversible pulpitis were included. Additionally, relevant supporting literature was also used where necessary.

Results

Initially, 118 papers were selected from PubMed and 68 were selected from Cochrane. Five additional articles were retrieved from Google Search. Following the elimination of duplicates and irrelevant articles, 35 studies were selected meeting the criteria. It was observed that there was moderate evidence to suggest that some premedications were partially effective for the enhancement of mandibular anesthetic effect in irreversible pulpitis.

Conclusion

Though some medications appear to be promising, further supporting research will help highlight this significant topic which requires further clarification.