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

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

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

Different Pharmacokinetics of Tramadol, O-Demethyltramadol and N-Demethyltramadol in Postoperative Surgical Patients From Those Observed in Medical Patients

Background: Most studies examining tramadol metabolism have been carried out in non-surgical patients and with oral tramadol. The aim of this study was 1) to measure concentrations of tramadol, O-demethyltramadol (ODT), and N-demethyltramadol (NDT) in the surgical patients admitted to the intensive care unit (ICU) within the first 24 postoperative hours after intravenous application of tramadol, and 2) to examine the effect of systemic inflammation on tramadol metabolism and postoperative pain. Methods: A prospective observational study was carried out in the surgical ICU in the tertiary hospital. In the group of 47 subsequent patients undergoing major abdominal surgery, pre-operative blood samples were taken for CYP2D6 polymorphism analysis. Systemic inflammation was assessed based on laboratory and clinical indicators. All patients received 100 mg of tramadol intravenously every 6 h during the first postoperative day. Postoperative pain was assessed before and 30 min after tramadol injections. Tramadol, ODT, and NDT concentrations were determined by high-performance liquid chromatography. Results: CYP2D6 analysis revealed 2 poor (PM), 22 intermediate (IM), 22 extensive (EM), and 1 ultrafast metabolizer. After a dose of 100 mg of tramadol, t1/2 of 4.8 (3.2-7.6) h was observed. There were no differences in tramadol concentration among metabolic phenotypes. The area under the concentration-time curve at the first dose interval (AUC1-6) of tramadol was 1,200 (917.9-1944.4) μg ×h ×L-1. NDT concentrations in UM were below the limit of quantification until the second dose of tramadol was administrated, while PM had higher NDT concentrations compared to EM and IM. ODT concentrations were higher in EM, compared to IM and PM. ODT AUC1-6 was 229.6 (137.7-326.2) μg ×h ×L-1 and 95.5 (49.1-204.3) μg ×h ×L-1 in EM and IM, respectively (p = 0.004). Preoperative cholinesterase activity (ChE) of ≤4244 U L-1 was a cut-off value for a prediction of systemic inflammation in an early postoperative period. NDT AUC1-6 were significantly higher in patients with low ChE compared with normal ChE patients (p = 0.006). Pain measurements have confirmed that sufficient pain control was achieved in all patients after the second tramadol dose, except in the PM. Conclusions: CYP2D6 polymorphism is a major factor in O-demethylation, while systemic inflammation accompanied by low ChE has an important role in the N-demethylation of tramadol in postoperative patients. Concentrations of tramadol, ODT, and NDT are lower in surgical patients than previously reported in non-surgical patients. Clinical Trial Registration: ClinicalTrials.gov, NCT04004481.

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.

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.

Misuse of Tramadol in the United States: An Analysis of the National Survey of Drug Use and Health 2002-2017

Objective:

To analyze the rates of misuse - that is, use in any way not directed by a doctor - of products containing oral tramadol, a Schedule IV opioid, from the National Survey of Drug Use and Health (NSDUH), as compared to comparator Schedule II opioids (morphine, oxycodone, and hydrocodone) and alprazolam, a commonly prescribed Schedule IV controlled substance in the U.S.

Methods:

The NSDUH is a congressionally mandated household survey that collects information on tobacco, alcohol, and drug use, mental health and other health-related issues in the US. A cross-sectional surveillance study design was used to examine lifetime and past year misuse of oral tramadol and comparators of interest among NSHUH respondents aged 12 years or older. Based on when particular data were available, the past-year misuse analysis includes NSDUH data from 2015 to 2017, and the lifetime misuse analysis includes NSDUH data from 2002 to 2014.

Results:

In 2015 to 2017, past-year misuse of oral tramadol was approximately 4% of the total number of prescriptions, versus 7% to 8% for all of the comparators when adjusted for drug availability. In 2002 to 2014, lifetime misuse of oral tramadol remained at 1.5% or less over the 13-year period, and was lower than reported for hydrocodone (6%) and oxycodone (4%), respectively. Comparison of oral tramadol and alprazolam showed misuse of tramadol was also much lower than alprazolam. Too few reports of tramadol misuse by injection (n = 7) were reported, versus 570, 1096, and 32 reports of injection of morphine, oxycodone, and hydrocodone, respectively, during the 16-year analysis period to allow for any population-based estimation. Only morphine has an intravenous formulation available and tramadol was not available as an intravenous formulation in the U.S. during that time period.

Conclusions:

This analysis shows a low prevalence of oral tramadol misuse, relative to other commonly prescribed opioids, in a nationally representative sample of noninstitutionalized US residents. Estimates of reported oral tramadol misuse have remained relatively stable over time and are substantially lower than those reported for comparators when adjusted for prescription volume. Reports of oral tramadol misuse are also much less than alprazolam, another Schedule IV drug.

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.