Disorder Due Cytochrome P450 CYP2D6 VariantNCT03859622
CYP2D6 Polymorphism in Patients of General Practice in Austria
An observational study of Disorder Due Cytochrome P450 CYP2D6 Variant, run by Karl Landsteiner Institute for Systematics in General Medicine at 1 site in Austria.
Trial summary
The CYP 2D6 enzyme metabolizes a significant number of drugs frequently prescribed in general practice/ family medicine. Various genetically different variants define if the patient is an ultra-rapid (UM), an normal (NM) (the normal case), an intermediate (IM) or a poor metabolizer (PM). Read more about this study
- Who is it for?
- Ages 18 to 100 years
- Conditions the study is for
- Disorder Due Cytochrome P450 CYP2D6 Variant
- How many people
- 289 participants
- Where
- 1 siteAustria
- Study dates
- 9 Oct 2017to 9 Oct 2018
- Phase
- Observational
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 18 to 100 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Unselected consecutive patients of an Austrian general practice suffering from chronic diseases visting the practice office for a routine blood test
Who may be able to join
- Patients with clinical diagnosis of hypertension, diabetes, chronic heart failure, hyperlipidemias, depression, schizophrenia, cardial arrhythmias, thyroid diseases and dementia
Who cannot join
- acute infectious diseases
Trial locations and contacts
1 site in 1 country.
About this study
Official title: CYP2D6 Polymorphism Defining UM, IM, NM and PM Status in Unselected Medically Treated Patients of General Practice in Austria
The CYP 2D6 enzyme metabolizes a significant number of drugs frequently prescribed in general practice/ family medicine. Various genetically different variants define if the patient is an ultra-rapid (UM), an normal (NM) (the normal case), an intermediate (IM) or a poor metabolizer (PM). It is estimated that approximately 20- 25 % of frequently described drugs are activated to more active or metabolized to ineffective or less effective drugs by CYP 2D6. Substrates of CYP 2D6 are mainly antidepressants, neuroleptics, opioids (e.g. codeine), beta-blockers, anti-arrhythmic drugs and various other single drugs. In case of an UM a drug can be metabolized too rapidly losing its therapeutic effect, requiring a higher dosage, or it can have a toxic effect, if it is converted too rapidly in the effective form (e.g. codeine). If metabolized too slowly (PM) it can accumulate and reach toxic levels.
In this observational study (1) data relating to the number of patients of a single Austrian general practice receiving one or more drugs metabolized by CYP 2D6 are collected by extracting their electronic records of the last 3 years. In addition (2) consecutive patients with unknown genetic status of their CYP 2D6 enzyme visiting the surgery for a routine blood test due to various reasons, are additionally tested for their CYP 2D6 metabolizing status, if they actually take a drug metabolized by CYP 2D6.
The aim of the study is to generate CYP 2D6 polymorphism data from Caucasian patients of an average Austrian general practice for the first time, which allows to group patients according to their NM, UM, IM and PM status. This can be of considerable clinical relevance when prescribing specific drugs. This study tries to investigate in how many patients the knowledge of the CYP 2D6 metabolizing status could have an influence on choosing the actually prescribed drug. In addition we plan to describe the distribution of frequent and relevant CYP 2D6 alleles including their combinations in patients of an average Austrian general practice for comparison reasons with other Caucasian populations.
Read the detailed description
Study population:
Unselected consecutive patients of the practice office visiting the surgery for a routine blood sampling due to various medical conditions and who are prescribed or have been prescribed drugs metabolized by the CYP2D6 enzyme (or drugs being a strong inhibitor of CYP 2D6) during the last 3 years. Only in these patients CYP2D6 polymorphism is determined using a fraction of the EDTA-blood sample. No further genetic investigations or additional blood collections are performed.
Patients who are considered to be eligible to participate in the study have to sign an informed consent after being informed about the aims of the study.
Blood sampling and processing of the specimens:
A standardized blood sampling using a Vacutainer system with filling of an EDTA tube (4 ml) for the red and white blood count is performed. 300 microliters of the collected blood are used for further determination of the CYP2D6 polymorphism.
Isolation of DNA:
DNA is extracted from EDTA blood in the practice laboratory by using the Spin Micro Extraction Kit® (ViennaLab,Vienna). The concentration and quality of DNA is measured using a Bio Photometer plus (Eppendorf). The extracted DNA is stored at -81°C in an ultra-low temperature deep freezer (U101-86, New Brunswick Scientific Co., Inc) without any further additives.
Real-time PCR for determination of copy number of the CYP2D6 gene:
For the determination of the copy number of the CYP2D6 gene a real-time PCR in triplicates on an ABI StepOnePlus by using the CYP2D6 RealFast™ CNV Assay (ViennaLab) is performed in the practice laboratory.
The test is based on the fluorogenic 5' nuclease assay, also known as TaqMan® assay. Each reaction contains gene-specific primer pairs for amplification of CYP2D6 and endogenous control (EC) gene fragments with 141 bp each. Further components are two dual-labeled, gene-specific hydrolysis probes, the FAM-labeled CYP2D6 probe and the HEX-labeled EC probe, which hybridize to an internal sequence of the amplified fragments. The proximity of the 5'-fluorescent reporter and 3'-quencher dye on intact probes prevents the reporter from fluorescing. During the extension phase of PCR the 5' - 3' exonuclease activity of Taq DNA polymerase cleaves the 5'-fluorescent reporter from the hybridized probe. The physical separation of the fluorophore from the quencher dye generates a fluorescent signal in real-time, which is proportional to the accumulated PCR product. The CYP2D6 RealFast™ CNV Assay is a relative quantitation assay and compares the amount of both nucleic acid targets (CYP2D6 and EC) in relation to the CYP2D6 CNV Calibrator. The EC gene is used to normalize fluorescence signals between different samples and serves as a PCR positive control.
For additional normalization of data ROX dye to a final concentration of 1 microliter to the 2 x Probe Mix is added.
RT- PCR cycling conditions for the ABI StepOneplus cycler: Initial denaturation: 95°C 10 min 1 cycle; denaturation 95°C 15 sec 40 cycles; annealing /extension 60°C 1 min.
PCR and hybridisation for CYP2D6 allele determination by the PGX-CYP2D StripAssay™:
This assay is used for a subset of samples in this study and covers only 3 polymorphic loci: 1795delT (2D6*6), 1934G>A (2D6*4) and 2637delA (2D6*3). The test principle and procedure are similar to the PGX-CYP2D6 XL StripAssay® as described below but using different cycling conditions for the Palm-Cycler (Corbett Life Science): pre-PCR: 94°C/2 min; thermocycling: 94°C/15 sec.- 58°C/ 30 sec.-72°C/30 sec (35 cycles); final extension: 72°C/3 min.
PCR and hybridisation for CYP2D6 allele determination by the PGX-CYP2D6 XL StripAssay®:
For the determination of 19 clinically relevant CYP2D6 alleles (*1; *2 A, *2 B-M; *3, *4A-H, K, L or P, *4J or N, *4M; *5; *6 A, B or D, *6C; *7, *8; *9,; *10A or B, *10 C or D; *11; *12; *14; *15; *17; *29; *35; *39; *40 or *58; *41) a PCR amplification on a Palm-Cycler (Corbett Life Science, Eight Mile Plains, QLD 4113, Australia) using biotinylated primers is first performed. The amplification products are further hybridized to a test strip containing allele-specific oligonucleotide probes immobilized as an array of parallel lines. Bound biotinylated sequences are detected using streptavidin-alkaline phosphatase and color substrates. The evaluation of this reaction is done manually by using the StripAssay®-Evaluator (ViennaLab,Vienna), a proprietary PC program to determine the homozygous or heterozygous genotype.
Cycling conditions for the Palm-Cycler (Corbett Life Science): pre-PCR: 95°C/4 min; thermocycling: 95°C/25 sec.- 60°C/ 45sec.-72°C/1min (36 cycles); final extension: 72°C/3 min.
Statistics:
The data were recorded and analyzed using Microsoft Excel Version 10 and the R Language and Environment for Statistical Computing and Graphics, Version 2.9. Standard methods are used for the description of data (frequencies and percentages for categorical data, mean and standard deviation for continuous data). To compare frequencies of CYP2D6-specific drugs prescribed in the single practice with the total number of the respective prescriptions in Lower Austria, Spearman's rank correlation-coefficient is calculated. Differences between groups were calculated by paired t-test. A p-value < 0.05 was considered to indicate statistical significance.
The Hardy-Weinberg- equilibrium was calculated using Fisher´s Exact Chi-Square test due to the small numbers of genotypes.
- Keywords
- Cytochrome P 450 CYP2D6 Variants, Genetic polymorphism, Practice, Family, Drug metabolism
What is being measured
The primary outcome is the main question the study is designed to answer.
Frequency of Metabolizer Status (PM, IM, NM, UM) in Patients
Remark: each participant possesses a) two individual CYP2D6 alleles, b) from the combination of these two alleles one individual genotype is derived and c) from this genotype the genetically determined metabolizer status (PM, IM, NM, UM) is derived.
A patient can be considered a ultra-rapid (UM), a normal (NM), an intermediate (IM), or a poor metabolizer (PM) of a given drug
Measured: 1 Year
Frequency of CYP2D6 Alleles in Patients
The frequency of 19 different CYP2D6 alleles in 287 patients is determined. In 2 out of all 289 patients the determination was not possible due to technical problems.
Remark: each participant possesses a) two individual CYP2D6 alleles, b) from the combination of these two alleles one individual genotype is derived and c) from this genotype the genetically determined metabolizer status (PM, IM, NM, UM) is derived.
Measured: 1 Year
Frequency of CYP2D6 Genotypes in Patients
The frequency of 61 different CYP2D6 genotypes in 287 patients is determined. In 2 out of all 289 patients the determination was not possible due to technical problems.
Remark: each participant possesses a) two individual CYP2D6 alleles, b) from the combination of these two alleles one individual genotype is derived and c) from this genotype the genetically determined metabolizer status (PM, IM, NM, UM) is derived.
Measured: 1 Year
Secondary outcomes (2)
Number of Participants in Whom the Family Physician Considered Prior Knowledge of Their Metabolizer Status Important Before the CYP2D6-specific Drug Was Prescriped.
In how many patients would family physician's knowledge of the CYP 2D6 metabolizer status (ultrarapid (UM), normal (NM), intermediate (IM) and poor (PM)) have been of importance before prescribing a CYP2D6 specific drug. Remark: The relevant drug has already already been prescribed before analysis has been taken place.
Measured: 1 Year
Specific Number of Patients of the Whole Practice Population Whose Electronic Health Records (EHRs) Were Assessed.
The specific number of participants of the practice population with a prescription of drugs metabolized by CYP 2D6 within the last 3 years. These data were extracted from the electronic health records (EHRs) of the practice office. For this data extraction enrollement in the study and signing an informed consent was not necessary. No other data (i.e. baseline assessments, other outcome measures and adverse events) were collected in this group.
Measured: 1 Year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Mar 2019
- Study start9 Oct 2017
- Primary completion9 Oct 2018
- Study completion9 Oct 2018
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Disorder Due Cytochrome P450 CYP2D6 VariantStudies 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
- Other
- Time perspective
- Other
- Enrolment
- 289 participants (actual)
Sponsor and investigators
- Lead sponsor
- Karl Landsteiner Institute for Systematics in General Medicine
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Gustav Kamenski, Karl Landsteiner Institute for Systematics in General Medicine
- Investigators
- Gustav Kamenski, Principal investigator, Karl Landsteiner Institute for Systematics in General Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03859622
- Sponsor's protocol ID
- KarlLandsteinerISGM CYP2D6
- Status last verified
- Oct 2019
- First submitted
- 20 Oct 2018
- Last updated
- 30 Oct 2019
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Distribution of CYP 2D6 polymorphism and CYP 2D6 metabolizer- status (based on allele combination and copy number Variation) can be shared with other researchers
Publications
Kamenski G, Ayazseven S, Berndt A, Fink W, Kamenski L, Zehetmayer S, Puhringer H. Clinical Relevance of CYP2D6 Polymorphisms in Patients of an Austrian Medical Practice: A Family Practice-Based Observational Study. Drugs Real World Outcomes. 2020 Mar;7(1):63-73. doi: 10.1007/s40801-019-00177-4.
PubMed 31863305
Study at a glance
From the registry record, last updated by the sponsor on 30 Oct 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- CYP2D6 Polymorphism Defining UM, IM, NM and PM Status in Unselected Medically Treated Patients of General Practice in Austria
- ClinicalTrials.gov ID
- NCT03859622
- Acronym / sponsor ID
- KarlLandsteinerISGM CYP2D6
- Keywords
- Cytochrome P 450 CYP2D6 Variants, Genetic polymorphism, Practice, Family, Drug metabolism
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 289 participants (actual)
- Lead sponsor
- Karl Landsteiner Institute for Systematics in General MedicineUniversity, hospital or other
- Study start
- 9 Oct 2017 (actual)
- Primary completion
- 9 Oct 2018 (actual)
- Study completion
- 9 Oct 2018 (actual)
- First posted
- 1 Mar 2019 (actual)
- Results
- Posted 30 Oct 2019
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The CYP 2D6 enzyme metabolizes a significant number of drugs frequently prescribed in general practice/ family medicine. Various genetically different variants define if the patient is an ultra-rapid (UM), an normal (NM) (the normal case), an intermediate (IM) or a poor metabolizer (PM). It is estimated that approximately 20- 25 % of frequently described drugs are activated to more active or metabolized to ineffective or less effective drugs by CYP 2D6. Substrates of CYP 2D6 are mainly antidepressants, neuroleptics, opioids (e.g. codeine), beta-blockers, anti-arrhythmic drugs and various other single drugs. In case of an UM a drug can be metabolized too rapidly losing its therapeutic effect, requiring a higher dosage, or it can have a toxic effect, if it is converted too rapidly in the effective form (e.g. codeine). If metabolized too slowly (PM) it can accumulate and reach toxic levels.
In this observational study (1) data relating to the number of patients of a single Austrian general practice receiving one or more drugs metabolized by CYP 2D6 are collected by extracting their electronic records of the last 3 years. In addition (2) consecutive patients with unknown genetic status of their CYP 2D6 enzyme visiting the surgery for a routine blood test due to various reasons, are additionally tested for their CYP 2D6 metabolizing status, if they actually take a drug metabolized by CYP 2D6.
The aim of the study is to generate CYP 2D6 polymorphism data from Caucasian patients of an average Austrian general practice for the first time, which allows to group patients according to their NM, UM, IM and PM status. This can be of considerable clinical relevance when prescribing specific drugs. This study tries to investigate in how many patients the knowledge of the CYP 2D6 metabolizing status could have an influence on choosing the actually prescribed drug. In addition we plan to describe the distribution of frequent and relevant CYP 2D6 alleles including their combinations in patients of an average Austrian general practice for comparison reasons with other Caucasian populations.
Detailed description
Study population:
Unselected consecutive patients of the practice office visiting the surgery for a routine blood sampling due to various medical conditions and who are prescribed or have been prescribed drugs metabolized by the CYP2D6 enzyme (or drugs being a strong inhibitor of CYP 2D6) during the last 3 years. Only in these patients CYP2D6 polymorphism is determined using a fraction of the EDTA-blood sample. No further genetic investigations or additional blood collections are performed.
Patients who are considered to be eligible to participate in the study have to sign an informed consent after being informed about the aims of the study.
Blood sampling and processing of the specimens:
A standardized blood sampling using a Vacutainer system with filling of an EDTA tube (4 ml) for the red and white blood count is performed. 300 microliters of the collected blood are used for further determination of the CYP2D6 polymorphism.
Isolation of DNA:
DNA is extracted from EDTA blood in the practice laboratory by using the Spin Micro Extraction Kit® (ViennaLab,Vienna). The concentration and quality of DNA is measured using a Bio Photometer plus (Eppendorf). The extracted DNA is stored at -81°C in an ultra-low temperature deep freezer (U101-86, New Brunswick Scientific Co., Inc) without any further additives.
Real-time PCR for determination of copy number of the CYP2D6 gene:
For the determination of the copy number of the CYP2D6 gene a real-time PCR in triplicates on an ABI StepOnePlus by using the CYP2D6 RealFast™ CNV Assay (ViennaLab) is performed in the practice laboratory.
The test is based on the fluorogenic 5' nuclease assay, also known as TaqMan® assay. Each reaction contains gene-specific primer pairs for amplification of CYP2D6 and endogenous control (EC) gene fragments with 141 bp each. Further components are two dual-labeled, gene-specific hydrolysis probes, the FAM-labeled CYP2D6 probe and the HEX-labeled EC probe, which hybridize to an internal sequence of the amplified fragments. The proximity of the 5'-fluorescent reporter and 3'-quencher dye on intact probes prevents the reporter from fluorescing. During the extension phase of PCR the 5' - 3' exonuclease activity of Taq DNA polymerase cleaves the 5'-fluorescent reporter from the hybridized probe. The physical separation of the fluorophore from the quencher dye generates a fluorescent signal in real-time, which is proportional to the accumulated PCR product. The CYP2D6 RealFast™ CNV Assay is a relative quantitation assay and compares the amount of both nucleic acid targets (CYP2D6 and EC) in relation to the CYP2D6 CNV Calibrator. The EC gene is used to normalize fluorescence signals between different samples and serves as a PCR positive control.
For additional normalization of data ROX dye to a final concentration of 1 microliter to the 2 x Probe Mix is added.
RT- PCR cycling conditions for the ABI StepOneplus cycler: Initial denaturation: 95°C 10 min 1 cycle; denaturation 95°C 15 sec 40 cycles; annealing /extension 60°C 1 min.
PCR and hybridisation for CYP2D6 allele determination by the PGX-CYP2D StripAssay™:
This assay is used for a subset of samples in this study and covers only 3 polymorphic loci: 1795delT (2D6*6), 1934G>A (2D6*4) and 2637delA (2D6*3). The test principle and procedure are similar to the PGX-CYP2D6 XL StripAssay® as described below but using different cycling conditions for the Palm-Cycler (Corbett Life Science): pre-PCR: 94°C/2 min; thermocycling: 94°C/15 sec.- 58°C/ 30 sec.-72°C/30 sec (35 cycles); final extension: 72°C/3 min.
PCR and hybridisation for CYP2D6 allele determination by the PGX-CYP2D6 XL StripAssay®:
For the determination of 19 clinically relevant CYP2D6 alleles (*1; *2 A, *2 B-M; *3, *4A-H, K, L or P, *4J or N, *4M; *5; *6 A, B or D, *6C; *7, *8; *9,; *10A or B, *10 C or D; *11; *12; *14; *15; *17; *29; *35; *39; *40 or *58; *41) a PCR amplification on a Palm-Cycler (Corbett Life Science, Eight Mile Plains, QLD 4113, Australia) using biotinylated primers is first performed. The amplification products are further hybridized to a test strip containing allele-specific oligonucleotide probes immobilized as an array of parallel lines. Bound biotinylated sequences are detected using streptavidin-alkaline phosphatase and color substrates. The evaluation of this reaction is done manually by using the StripAssay®-Evaluator (ViennaLab,Vienna), a proprietary PC program to determine the homozygous or heterozygous genotype.
Cycling conditions for the Palm-Cycler (Corbett Life Science): pre-PCR: 95°C/4 min; thermocycling: 95°C/25 sec.- 60°C/ 45sec.-72°C/1min (36 cycles); final extension: 72°C/3 min.
Statistics:
The data were recorded and analyzed using Microsoft Excel Version 10 and the R Language and Environment for Statistical Computing and Graphics, Version 2.9. Standard methods are used for the description of data (frequencies and percentages for categorical data, mean and standard deviation for continuous data). To compare frequencies of CYP2D6-specific drugs prescribed in the single practice with the total number of the respective prescriptions in Lower Austria, Spearman's rank correlation-coefficient is calculated. Differences between groups were calculated by paired t-test. A p-value < 0.05 was considered to indicate statistical significance.
The Hardy-Weinberg- equilibrium was calculated using Fisher´s Exact Chi-Square test due to the small numbers of genotypes.
Study design
- Observational model
- Other
- Time perspective
- Other
Who may qualify
- Ages
- 18 to 100 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Unselected consecutive patients of an Austrian general practice suffering from chronic diseases visting the practice office for a routine blood test
Key inclusion criteria (1 listed)
- Patients with clinical diagnosis of hypertension, diabetes, chronic heart failure, hyperlipidemias, depression, schizophrenia, cardial arrhythmias, thyroid diseases and dementia
Key exclusion criteria (1 listed)
- acute infectious diseases
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
Frequency of Metabolizer Status (PM, IM, NM, UM) in Patients
Time frame: 1 Year
Remark: each participant possesses a) two individual CYP2D6 alleles, b) from the combination of these two alleles one individual genotype is derived and c) from this genotype the genetically determined metabolizer status (PM, IM, NM, UM) is derived. A patient can be considered a ultra-rapid (UM), a normal (NM), an intermediate (IM), or a poor metabolizer (PM) of a given drug
Frequency of CYP2D6 Alleles in Patients
Time frame: 1 Year
The frequency of 19 different CYP2D6 alleles in 287 patients is determined. In 2 out of all 289 patients the determination was not possible due to technical problems. Remark: each participant possesses a) two individual CYP2D6 alleles, b) from the combination of these two alleles one individual genotype is derived and c) from this genotype the genetically determined metabolizer status (PM, IM, NM, UM) is derived.
Frequency of CYP2D6 Genotypes in Patients
Time frame: 1 Year
The frequency of 61 different CYP2D6 genotypes in 287 patients is determined. In 2 out of all 289 patients the determination was not possible due to technical problems. Remark: each participant possesses a) two individual CYP2D6 alleles, b) from the combination of these two alleles one individual genotype is derived and c) from this genotype the genetically determined metabolizer status (PM, IM, NM, UM) is derived.
2 secondary outcomes
Number of Participants in Whom the Family Physician Considered Prior Knowledge of Their Metabolizer Status Important Before the CYP2D6-specific Drug Was Prescriped.
Time frame: 1 Year
Specific Number of Patients of the Whole Practice Population Whose Electronic Health Records (EHRs) Were Assessed.
Time frame: 1 Year
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Oct 2019.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 31863305Kamenski G, Ayazseven S, Berndt A, Fink W, Kamenski L, Zehetmayer S, Puhringer H. Clinical Relevance of CYP2D6 Polymorphisms in Patients of an Austrian Medical Practice: A Family Practice-Based Observational Study. Drugs Real World Outcomes. 2020 Mar;7(1):63-73. doi: 10.1007/s40801-019-00177-4.
- Individual participant dataSharing planned: Yes. Distribution of CYP 2D6 polymorphism and CYP 2D6 metabolizer- status (based on allele combination and copy number Variation) can be shared with other researchers
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. This study is not recruiting at the moment.
Gustav Kamenski principal investigator
Karl Landsteiner Institute for Systematics in General Medicine
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 Disorder Due Cytochrome P450 CYP2D6 Variant, run by Karl Landsteiner Institute for Systematics in General Medicine at 1 site in Austria.
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 1 inclusion and 1 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: finished, as of the sponsor's last update on 30 Oct 2019. 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 Austria. 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?
Yes. Results are posted in the registry (first posted 30 Oct 2019). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Frequency of Metabolizer Status (PM, IM, NM, UM) in Patients (time frame: 1 Year). The study lists 3 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 NCT03859622, which also lists 1 linked publication.
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 30 Oct 2019; AzTrials last refreshed its copy on 6 Nov 2026.