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

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

BACKGROUND AND IMPORTANCE

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

OBJECTIVE

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

DESIGN, SETTINGS, AND PARTICIPANTS

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

OUTCOMES MEASURE AND ANALYSIS

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

MAIN RESULTS

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

CONCLUSIONS

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

Oxycodone vs. tramadol in postoperative parent-controlled intravenous analgesia in children: a prospective, randomized, double-blinded, multiple-center clinical trial

BACKGROUND

Management of acute postoperative pain is one of the major challenges in pediatric patients. Oral oxycodone has shown good pain relief in postoperative pain relief in children, but no studies have investigated intravenous oxycodone in this context.

OBJECTIVE

whether oxycodone PCIA can provide adequate and safe postoperative pain relief, in comparison to tramadol as reference opioid drug.

DESIGN

a randomized, double-blind, parallel, multi-center clinical trial.

SETTING

five university medical centers and three teaching hospitals in China.

PARTICIPANTS

patients aged 3-month-old to 6-year-old undergoing elective surgery under general anesthesia.

INTERVENTION

patients were randomly allocated to either tramadol (n = 109) or oxycodone (n = 89) as main postoperative opioid analgesic. Tramadol or oxycodone were administered with a loading dose at the end of surgery (1 or 0.1 mg.kg^-1, respectively), then with a parent-controlled intravenous device with fixed bolus doses only (0.5 or 0.05 mg.kg-1, respectively), and a 10-min lockout time.

OUTCOMES

the primary outcome was adequate postoperative pain relief, defined as a face, legs, activity, cry, and consolability (FLACC) score < 4/10 in the post-anesthesia care unit (PACU), with no need for an alternative rescue analgesia. FLACC was measured 10 min after extubation then every 10 min until discharge from PACU. Analgesia was currently conducted with the boluses of either tramadol or oxycodone if FLACC was ≥ 3, up to three bolus doses, after what rescue alternative analgesia was administered.

RESULTS

tramadol and oxycodone provided a similar level of adequate postoperative pain relief in PACU and in the wards. No significant differences were either noted for the raw FLACC scores, the bolus dose demand in PACU, the time between the first bolus dose and discharge from PACU, analgesic drug consumption, bolus times required in the wards, function activity score, or the parents' satisfaction. The main observed side effects in both groups were nausea and vomiting, with no difference between groups. However, patients in the oxycodone group showed less sedation levels and had a shorter stay in the PACU, compared with the tramadol group.

CONCLUSIONS

an adequate postoperative analgesia can be achieved with intravenous oxycodone, this with less side effects than tramadol. It can therefore be a choice for postoperative pain relief in pediatric patients.

TRIAL REGISTRATION

The study was registered at www.chictr.org.cn (Registration number: ChiCTR1800016372; date of first registration: 28/05/2018; updated date:06/01/2023).

Effect of common OPRM1, COMT, SLC6A4, ABCB1, and CYP2B6 polymorphisms on perioperative analgesic and propofol demands on patients subjected to thyroidectomy surgery

BACKGROUND

Perioperative anesthetic and/or analgesic demand present considerable variation, and part of that variation appears to be genetic in origin. Here we investigate the impact of common polymorphisms in OPRM1, COMT, SLC6A4, ABCB1, and CYP2B6 genes, on the intra-operative consumption of remifentanil and propofol, as well as the postoperative analgesic needs, in patients subjected to thyroidectomy surgery.

METHODS

We conducted a prospective cohort study with 90 patients scheduled to undergo elective thyroidectomy, under total intravenous anesthesia achieved by target control infusion (TCI) of propofol and remifentanil. Postoperative analgesics were administered by protocol and on-demand by the individual patient. Genotyping was established by PCR-RFLP methods. Genotyping data, intra-operative hemodynamics, and total consumption of remifentanil and propofol, as well as postoperative analgesic needs and pain perception, were recorded for each individual.

RESULTS

Patients with the ABCB1 3435TT genotype appeared to experience significantly less pain within one hour post-operatively, compared to C carriers [mean VAS (SD) = 0.86 (1.22) vs. 2.42 (1.75); p = 0.017], a finding limited to those seeking rescue analgesic treatment. Intra-operatively, homozygotes patients for the minor allele of OPRM1 A118G and CYP2B6 G516T appeared to consume less remifentanil [mean (SD) = 9.12 (1.01) vs. 13.53 (5.15), for OPRM1 118GG and A carriers] and propofol [median (range) = 14.95 (11.53, 1359.5) vs. 121.4 (1.43, 2349.4), for CYP2B6 516TT and G carriers, respectively] but the difference was not statistically significant in our sample.

CONCLUSIONS

The ABCB1 C3435T polymorphism appears to affect the postoperative perception of surgical pain among patients with low pain threshold. The small number of minor allele homozygotes for the OPRM1 A118G and CYP2B6 G516T polymorphisms precludes a definitive conclusion regarding the inclusion of the latter in a TCI-programming algorithm, based on the results of this study.

CLINICAL TRIAL REGISTRATION NUMBER

ACTRN12616001598471.

Abdominoplasty as an acute postoperative pain model: insights from 8 years of clinical trials

ABSTRACT

To have a complete understanding of an experimental analgesic's efficacy in treating acute postoperative pain, it is necessary to understand its effect on both hard-tissue pain and soft-tissue pain. For this reason, regulatory bodies including the U.S. Food and Drug Administration and European EMA typically require drug developers to demonstrate efficacy in both hard-tissue and soft-tissue pain to grant a broad approval for an analgesic in acute postoperative pain. Hard-tissue models such as bunionectomy and molar extraction are well-validated and efficient with long histories in clinical trials, but until recently, a similarly well-standardized and fast-enrolling soft-tissue model was not available. Abdominoplasty was developed as an acute postoperative pain model and introduced to the clinical trial marketplace in 2014 to address the need for a viable soft-tissue model. Since then, at least 13 industry-sponsored studies, including multiple pivotal trials, have been conducted, providing a data set that can be used to interrogate the model's strengths and weaknesses. The authors outline the development history of abdominoplasty, discuss key clinical and design characteristics of the model, and review public data from abdominoplasty acute pain studies available to date. The data suggest that abdominoplasty is a well-validated soft-tissue surgical model that provides high-quality experimental outputs, enabling the efficacy of investigational analgesics in soft-tissue pain to be understood successfully.

Comparative risk-benefit profiles of weak opioids in the treatment of osteoarthritis: a network meta-analysis of randomized controlled trials

BACKGROUND

Despite their poor tolerance, weak opioids are still the most commonly-prescribed medicine for osteoarthritis (OA)-related pain. The objective of this network meta-analysis was to comparatively examine the efficacy and safety of weak opioids in OA treatment.

METHODS

Databases including PubMed, Embase, Cochrane Library and Web of Science were searched from inception to August 5, 2020 to retrieve randomized controlled trials (RCTs) comparing weak opioids with placebo or between one another in OA patients. Bayesian network meta-analysis was performed on the following outcomes of interest, namely the change-from-baseline score in pain relief, gastrointestinal (GI) adverse events (AEs), central nervous system (CNS) AEs, and total number of AEs (i.e., the number of subjects experiencing any AE for at least once) during follow-up.

RESULTS

A total of 14 RCTs involving four types of weak opioids were included in this meta-analysis. Compared to placebo, tramadol (standardized mean difference [SMD] = -0.34, 95% credible interval [CrI]: -0.53 to -0.18) and codeine (SMD = -0.39, 95% CrI: -0.79 to -0.04) were effective for pain relief, but involved a higher risk of GI AEs, CNS AEs and total number of AEs. Dextropropoxyphene demonstrated a significantly lower risk of GI AEs (OR = 0.28, 95%CrI: 0.17 to 0.51), CNS AEs (OR = 0.29, 95%CrI: 0.11 to 0.78) and total number of AEs (OR = 0.35, 95%CrI: 0.15 to 0.82) compared to codeine. Dihydrocodeine had a better safety profile in CNS AEs (SUCRA = 64.8%) and total number of AEs (SUCRA = 66.6%).

CONCLUSIONS

The results of the present study confirmed that tramadol and codeine were effective drugs for the treatment of OA, but involved considerable safety issues. Dextropropoxyphene and dihydrocodeine exhibited a relatively good safety profile but their efficacy still warrant further investigation.

Endogenous opiates and behavior: 2020

This paper is the forty-third consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2020 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Emerging drugs for the treatment of postsurgical pain

INTRODUCTION

Postoperative pain is a distressful experience and remains to be a significant concern after surgery. Current agents either fail to prevent or minimize postoperative pain or cause a series of adverse effects, addiction, or abuse. Opioids have been the gold standard in the treatment of postoperative pain despite their well-described adverse effects. Many new agents with different mechanisms of action have been recently introduced to address this issue.

AREAS COVERED

This current review summarizes the list of new and emerging drugs investigated for their efficacy in controlling the postoperative pain and decreasing the need for rescue opioid use, adverse effect profile, abuse, and addiction potential.

EXPERT OPINION

Opioids have unrivaled analgesic efficacy. However adverse effects of opioids led to the search for better options. In mild pain most of the emerging drugs have been shown to control postoperative pain and decrease the use of rescue opioid, however fail to control pain after major surgeries causing severe pain. Specific agents such as Oliceridine, new local anesthetics, etc., are effective in controlling severe pain and hold a promise to replace opioids in the near future.

Efficacy and Safety of Intravenously Administered Tramadol in Patients with Moderate to Severe Pain Following Bunionectomy: A Randomized, Double-Blind, Placebo-Controlled, Dose-Finding Study

INTRODUCTION

This study is part of the registrational program for intravenously administered (IV) tramadol in the USA and compared the analgesic benefit and tolerability of two doses of IV tramadol (50 mg and 25 mg) to placebo in adult patients undergoing bunionectomy, an orthopedic surgical model.

METHODS

This was a phase 3, multicenter, double-blind, three-arm, randomized, placebo-controlled, multiple-dose, parallel-group trial to evaluate IV tramadol in the management of postoperative pain following bunionectomy. Eligible patients were randomized (1:1:1 ratio) to IV tramadol 50 mg, 25 mg, or placebo. Primary endpoint was summary of pain intensity differences over 48 h (SPID48). Key secondary endpoints included SPID24, total consumption of rescue analgesia, and patient global assessment of efficacy (PGA). Safety assessments included treatment emergent adverse events (TEAEs), clinical laboratory tests, vital signs, and electrocardiograms (ECGs). Assessment of the dose-response was an important objective of the study.

RESULTS

The study established a dose response, with IV tramadol 50 mg demonstrating statistically significant benefit (p < 0.05) over placebo for primary and all key secondary efficacy endpoints, whereas tramadol 25 mg demonstrated intermediate results between the 50 mg and placebo arms. IV tramadol 50 mg was well tolerated; most common TEAEs were nausea and vomiting; and there were no meaningful differences among treatments for vital signs, ECG, and laboratory assessments. The largest proportion of patients completed tramadol 50 mg (98.6%) compared to tramadol 25 mg (91.8%) and placebo (88.2%).

CONCLUSION

IV tramadol 50 mg was effective and well tolerated as treatment for postoperative pain following bunionectomy surgery, while IV tramadol 25 mg, although well tolerated, was judged an ineffective dose for the treatment of pain in this setting. IV tramadol 50 mg was further developed in the registrational program for the USA.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT03290378.

IV Tramadol - A New Treatment Option for Management of Post-Operative Pain in the US: An Open-Label, Single-Arm, Safety Trial Including Various Types of Surgery

Purpose

There is a need to reduce exposure to Schedule II opioids in the United States (US) due to the ongoing opioid epidemic. Schedule II opioids have higher potential for abuse and misuse than Schedule IV opioids. This Phase 3, multicenter, single-arm, open-label, multiple-dose US trial evaluated the safety and tolerability of intravenous tramadol 50 mg, a Schedule IV opioid, in the management of postoperative pain in a real-world setting, where intravenous tramadol is not yet approved for use.

Patients and Methods

Patients undergoing a range of soft-tissue and orthopedic surgeries were enrolled. Intravenous tramadol 50 mg was given at hours 0, 2, 4, and every 4 h thereafter through up to 7 days of treatment. Non-opioid medications per treating physicians' discretion were allowed if additional pain relief was needed. Endpoints included treatment-emergent adverse events (TEAEs), laboratories, vital signs, electrocardiograms (ECGs), and patient global assessment (PGA) of effectiveness.

Results

A total of 251 patients were enrolled, with 4% discontinuing due to TEAE; no patient discontinued due to a lack of efficacy. Patients averaged 13 doses, resulting in average 48 h of exposure. Intravenous tramadol was well tolerated, with TEAEs consistent with known tramadol pharmacology. No unexpected findings were observed, with 95% of patients reporting study medication was good, very good, or excellent for controlling pain.

Conclusion

Outcomes from this real world use study demonstrated intravenous tramadol 50 mg was safe and well tolerated in the management of postoperative pain where intravenous conventional opioids are often used. Intravenous tramadol alone or coadministered with non-opioid medication (when needed) as a multimodal combination analgesia approach resulted in high patient satisfaction with their pain relief. In light of the US opioid epidemic, reducing the exposure to conventional opioids in these patients via use of IV tramadol may be possible.