Oxidative StressORRSNCT07338084
OpioidRedoxStudyII
An observational study of Oxidative Stress and Opioid Use, run by EPC Education s.r.o. at 1 site in Slovakia.
Trial summary
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. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Oxidative Stress, Opioid Use
- How many people
- 120 participants
- Where
- 1 siteSlovakia
- Study dates
- 30 Jun 2026to 31 Dec 2029
- How long will I take part?
- 3 Years
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
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.
Who may be able to join
- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Janka Vaskova, Prof. Dr. PhD. contact
About this study
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.
Read the 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.
- Conditions
- Oxidative Stress, Opioid Use
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Group 1 | Tramadol Cohort | |
| Group 2 | Tapentadol Cohort | |
| Group 3 | Buprenorphine - Morphin Cohort | |
| Group 4 | Fentanyl Cohort |
What is being measured
The primary outcome is the main question the study is designed to answer.
Redox Balance Assessed by Circulating Redox-Related Biomarkers
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.
Measured: At baseline (at enrollment)
Association Between Genetic Variants Related to Opioid Metabolism and Opioid-Related Adverse Effects
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.
Measured: From enrollment to 12 months after enrollment
Secondary outcomes (2)
Chronification Risk Assessment
Assessment of the risk of pain chronification using a validated pain chronification risk assessment questionnaire in adults receiving opioid therapy.
Measured: At baseline (at enrollment)
Pain Severity and Interference Assessed by the Brief Pain Inventory
Assessment of pain severity and pain-related interference with daily activities using the Brief Pain Inventory (BPI) questionnaire.
Measured: At baseline and during follow-up up to 12 months after enrollment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Jan 2026
- Study start30 Jun 2026 (estimated)
- Primary completion30 Dec 2026 (estimated)
- Study completion31 Dec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (11)Papers the sponsor has linked to this study.
- Other trials for Oxidative StressStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 120 participants (estimated)
- Target duration
- 3 Years
Sponsor and investigators
- Lead sponsor
- EPC Education s.r.o.
- Sponsor type
- University, hospital or other
- Collaborators
- Pavol Jozef Safarik University, F.D.Roosevelt Banska Bystrica Slovak Republic
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07338084
- Sponsor's protocol ID
- B1112025
- Acronym
- ORRS
- Status last verified
- Jan 2026
- First submitted
- 3 Jan 2026
- Last updated
- 13 Jan 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: 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.
Publications
Cleeland CS, Ryan KM. Pain assessment: global use of the Brief Pain Inventory. Ann Acad Med Singap. 1994 Mar;23(2):129-38.
PubMed 8080219Kotagal V, Pontone GM, Bohnen NI. Chronic pain and cognitive decline: exploring the link in aging and neurodegenerative disorders. Pain Med. 2015;16(3):430-442. PMCID: PMC4377400.
Martuliak I, Golubnitschaja O, Chvala L, Kapalla M, Ferencik M, Bubeliny M, Venglarcik M, Kocan L. Pain chronification risk assessment: advanced phenotyping and scoring for prediction and treatments tailored to individualized patient profile. EPMA J. 2024 Nov 15;15(4):739-750. doi: 10.1007/s13167-024-00383-3. eCollection 2024 Dec.
PubMed 39635026Richie M, Koob GF, Schulteis G. Genetic variability in ABCB1 and analgesic response: implications for morphine efficacy. J Pain. 2018;19(10):1090-1098. doi:10.1016/j.jpain.2018.04.004.
in W, Zhang Y, Chen D, et al. ABCB1 C3435T polymorphism affects opioid dose requirements through P-glycoprotein-mediated transport. Biomed Pharmacother. 2024;172:114007. doi:10.1016/j.biopha.2024.114007.
Rakvag TT, Klepstad P, Baar C, Kvam TM, Dale O, Kaasa S, Krokan HE, Skorpen F. The Val158Met polymorphism of the human catechol-O-methyltransferase (COMT) gene may influence morphine requirements in cancer pain patients. Pain. 2005 Jul;116(1-2):73-8. doi: 10.1016/j.pain.2005.03.032.
PubMed 15927391Ho KYY, Loh S, Lim JF, et al. Influence of OPRM1 and COMT polymorphisms on pain perception and opioid responses: a randomized controlled trial. Pharmacogenomics J. 2020;20(6):762-769. PMCID: PMC7651441.
Chidambaran V, Zhang X, Martin LJ, et al. Genetic predictors of postoperative respiratory depression after pediatric tonsillectomy: OPRM1 and ABCB1 variants. Pharmacogenomics J. 2015;15(5):430-435. PMID: 25349169.
Stamer UM, Stuber F, Muders T, Musshoff F. Respiratory depression with tramadol in a patient with renal impairment and CYP2D6 gene duplication. Anesth Analg. 2008 Sep;107(3):926-9. doi: 10.1213/ane.0b013e31817b796e.
PubMed 18713907Zeng L, Zhen J, Wang T, et al. Thioredoxin-1 regulates morphine-induced addictive behavior through redox modulation in the nucleus accumbens. Front Pharmacol. 2020;11:573434. doi:10.3389/fphar.2020.573434.
Ahmadi A, Shadboorestan A, Ahmatkesh A. Opioid administration and oxidative stress: a review of the literature. J Opioid Manag. 2017;13(1):35-44. PMID: 28296619.
Study at a glance
From the registry record, last updated by the sponsor on 13 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- OpioidRedoxStudyII
- ClinicalTrials.gov ID
- NCT07338084
- Acronym / sponsor ID
- ORRS / B1112025
- Conditions
- Oxidative Stress, Opioid Use
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 120 participants (estimated)
- Lead sponsor
- EPC Education s.r.o.University, hospital or other
- Collaborators
- Pavol Jozef Safarik University, F.D.Roosevelt Banska Bystrica Slovak Republic
- Study start
- 30 Jun 2026 (estimated)
- Primary completion
- 30 Dec 2026 (estimated)
- Study completion
- 31 Dec 2029 (estimated)
- First posted
- 13 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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 design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 3 Years
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Group 1 | – | –Tramadol Cohort |
| Group 2 | – | –Tapentadol Cohort |
| Group 3 | – | –Buprenorphine - Morphin Cohort |
| Group 4 | – | –Fentanyl Cohort |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- 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.
Key inclusion criteria (5 listed)
- 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
Key exclusion criteria (6 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
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.
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.
2 secondary outcomes
Chronification Risk Assessment
Time frame: 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
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Jan 2026.
- Background: PubMed 8080219Cleeland CS, Ryan KM. Pain assessment: global use of the Brief Pain Inventory. Ann Acad Med Singap. 1994 Mar;23(2):129-38.
- BackgroundKotagal V, Pontone GM, Bohnen NI. Chronic pain and cognitive decline: exploring the link in aging and neurodegenerative disorders. Pain Med. 2015;16(3):430-442. PMCID: PMC4377400.
- Background: PubMed 39635026Martuliak I, Golubnitschaja O, Chvala L, Kapalla M, Ferencik M, Bubeliny M, Venglarcik M, Kocan L. Pain chronification risk assessment: advanced phenotyping and scoring for prediction and treatments tailored to individualized patient profile. EPMA J. 2024 Nov 15;15(4):739-750. doi: 10.1007/s13167-024-00383-3. eCollection 2024 Dec.
- BackgroundRichie M, Koob GF, Schulteis G. Genetic variability in ABCB1 and analgesic response: implications for morphine efficacy. J Pain. 2018;19(10):1090-1098. doi:10.1016/j.jpain.2018.04.004.
- Backgroundin W, Zhang Y, Chen D, et al. ABCB1 C3435T polymorphism affects opioid dose requirements through P-glycoprotein-mediated transport. Biomed Pharmacother. 2024;172:114007. doi:10.1016/j.biopha.2024.114007.
- Background: PubMed 15927391Rakvag TT, Klepstad P, Baar C, Kvam TM, Dale O, Kaasa S, Krokan HE, Skorpen F. The Val158Met polymorphism of the human catechol-O-methyltransferase (COMT) gene may influence morphine requirements in cancer pain patients. Pain. 2005 Jul;116(1-2):73-8. doi: 10.1016/j.pain.2005.03.032.
- BackgroundHo KYY, Loh S, Lim JF, et al. Influence of OPRM1 and COMT polymorphisms on pain perception and opioid responses: a randomized controlled trial. Pharmacogenomics J. 2020;20(6):762-769. PMCID: PMC7651441.
- BackgroundChidambaran V, Zhang X, Martin LJ, et al. Genetic predictors of postoperative respiratory depression after pediatric tonsillectomy: OPRM1 and ABCB1 variants. Pharmacogenomics J. 2015;15(5):430-435. PMID: 25349169.
- Background: PubMed 18713907Stamer UM, Stuber F, Muders T, Musshoff F. Respiratory depression with tramadol in a patient with renal impairment and CYP2D6 gene duplication. Anesth Analg. 2008 Sep;107(3):926-9. doi: 10.1213/ane.0b013e31817b796e.
- BackgroundZeng L, Zhen J, Wang T, et al. Thioredoxin-1 regulates morphine-induced addictive behavior through redox modulation in the nucleus accumbens. Front Pharmacol. 2020;11:573434. doi:10.3389/fphar.2020.573434.
- BackgroundAhmadi A, Shadboorestan A, Ahmatkesh A. Opioid administration and oxidative stress: a review of the literature. J Opioid Manag. 2017;13(1):35-44. PMID: 28296619.
- Individual participant dataSharing planned: No. 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.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Janka Vaskova, Prof. Dr. PhD. contact
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Oxidative Stress and Opioid Use, run by EPC Education s.r.o. at 1 site in Slovakia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 13 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Slovakia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Ladislav Kocan, assoc. Prof MD (00421557891100, europainclinicsstudy@mail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Redox Balance Assessed by Circulating Redox-Related Biomarkers (time frame: At baseline (at enrollment)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07338084, which also lists 11 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Jan 2026; AzTrials last refreshed its copy on 29 Oct 2026.