OpioidRedoxStudyII (ORRS)

January 3, 2026 updated by: Europainclinics z.ú.

This observational study aims to examine the relationship between opioid use and redox balance in adults. Redox balance reflects the level of oxidative stress in the body, which is known to play an important role in many biological processes and diseases.

Participants who use opioids will be included in the study. No experimental treatment or changes to current medical care will be provided as part of this study. Biological samples may be collected to assess redox-related biomarkers, and relevant clinical and demographic information will be recorded.

The results of this study are expected to improve understanding of how opioid exposure is associated with redox balance in adults. This information may help inform future research on the biological effects of opioids and potential strategies to reduce harm associated with long-term opioid use.

Study Overview

Status

Not yet recruiting

Conditions

Detailed Description

Opioids are widely used for the management of acute and chronic pain; however, prolonged opioid exposure has been associated with a range of systemic effects beyond analgesia. Increasing evidence suggests that oxidative stress and alterations in redox balance may play a role in the biological effects of opioids, potentially contributing to tissue damage, inflammation, and other adverse outcomes.

The OpioidRedoxStudy II is an observational study designed to further investigate the association between opioid use and redox balance in adults. This study builds on previous findings by focusing on redox-related biomarkers that reflect oxidative and antioxidative processes in the human body. The study does not involve any experimental intervention, randomization, or modification of participants' current medical treatment.

Participants using opioids will be assessed using biological samples collected according to the study protocol. These samples will be analyzed for markers related to redox balance. In addition, relevant clinical, demographic, and opioid exposure data will be collected to allow for exploratory analyses of associations between opioid use patterns and redox-related measures.

The primary objective of this study is to characterize the relationship between opioid exposure and redox balance in adults. Secondary objectives include exploring potential associations between redox-related biomarkers and clinical characteristics. The findings of this study are intended to contribute to a better understanding of the biological effects of opioid use and to support future research aimed at reducing opioid-related harm.

Study Type

Observational

Enrollment (Estimated)

120

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Slovakia
      • Košice, Slovakia, 04011
        • University of Pavol JoSef Safarik

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The study population consists of adult patients receiving opioid therapy as part of routine clinical care. Participants are treated with tramadol, tapentadol, morphine, fentanyl, or buprenorphine and are enrolled into predefined observational cohorts based on the type of opioid used. The study population includes individuals with ongoing opioid exposure who are able to provide informed consent and comply with study procedures.

Description

Inclusion Criteria:

  • Adults aged 18 years or older
  • Receiving opioid therapy (tramadol, tapentadol, morphine, fentanyl, or buprenorphine) as part of routine clinical care
  • Stable opioid treatment for at least a predefined minimum period prior to enrollment (according to the study protocol)
  • Ability to provide written informed consent
  • Ability to comply with study procedures, including blood sampling and completion of questionnaires

Exclusion Criteria:

  • Acute opioid intoxication or withdrawal at the time of enrollment
  • Use of investigational drugs or participation in another interventional clinical trial that could interfere with study outcomes
  • Severe acute illness or unstable medical condition that, in the investigator's judgment, would interfere with study participation
  • Known pregnancy or breastfeeding
  • Inability to provide informed consent
  • Any condition that, in the opinion of the investigator, would make participation unsafe or compromise the quality of the collected data

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Group 1
Tramadol Cohort
Group 2
Tapentadol Cohort
Group 3
Buprenorphine - Morphin Cohort
Group 4
Fentanyl Cohort

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Redox Balance Assessed by Circulating Redox-Related Biomarkers
Time Frame: At baseline (at enrollment)
Assessment of redox balance using circulating redox-related biomarkers measured in blood-derived samples. Biomarker levels will be compared across opioid exposure cohorts to evaluate associations between opioid type and redox balance.
At baseline (at enrollment)
Association Between Genetic Variants Related to Opioid Metabolism and Opioid-Related Adverse Effects
Time Frame: From enrollment to 12 months after enrollment
Assessment of the association between selected genetic variants related to opioid metabolism and signaling and the occurrence of opioid-related adverse effects and treatment intolerance across opioid exposure cohorts.
From enrollment to 12 months after enrollment

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Chronification Risk Assessment
Time Frame: At baseline (at enrollment)
Assessment of the risk of pain chronification using a validated pain chronification risk assessment questionnaire in adults receiving opioid therapy.
At baseline (at enrollment)
Pain Severity and Interference Assessed by the Brief Pain Inventory
Time Frame: At baseline and during follow-up up to 12 months after enrollment
Assessment of pain severity and pain-related interference with daily activities using the Brief Pain Inventory (BPI) questionnaire.
At baseline and during follow-up up to 12 months after enrollment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Europainclinics z.ú.

Collaborators

Pavol Jozef Safarik University
F.D.Roosevelt Banska Bystrica Slovak Republic

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

June 30, 2026

Primary Completion (Estimated)

December 30, 2026

Study Completion (Estimated)

December 31, 2029

Study Registration Dates

First Submitted

January 3, 2026

First Submitted That Met QC Criteria

January 3, 2026

First Posted (Actual)

January 13, 2026

Study Record Updates

Last Update Posted (Actual)

January 13, 2026

Last Update Submitted That Met QC Criteria

January 3, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • B1112025

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared due to the sensitive nature of the collected data, including genetic information and detailed clinical variables. Data sharing is further restricted to ensure participant confidentiality and compliance with applicable data protection regulations.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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