CompletedNot Applicable

Impact of Genetic Polymorphism on Drug-Drug Interactions Involving CYP2D6

34 participantsStarted 2016-07

Plain-language summary

CYP2D6 is characterized by a huge variability in the general population, mainly because of genetic polymorphism and drug-drug interactions (DDIs). CYP2D6 genotype is known to have an impact on the extent of DDIs. Indeed several studies have pointed out differential DDIs extent according to CYP2D6 genotype. The terms phenoconversion and phenotype switch are both used to describe the phenomenon by which a given subject changes his phenotype to another due external influence such as DDIs. When given a sufficiently strong CYP2D6 inhibitor, the phenotype of an individual with no mutant allele (extensive metabolizer, EM) of CYP2D6 can be modified to a poor metabolizer (PM) phenotype. This vulnerability is also thought to be dependent on CYP2D6 genotype. Various combinations of alleles predict an EM genotype, which represents about 60 to 70% of the general population. The aim of the study is to determine whether the presence of genetic mutation in CYP2D6 has an impact on DDIs involving the CYP2D6 enzyme. Our interest focuses on CYP2D6 EM carriers of two fully functional alleles and carriers of one non-functional and one functional allele. In order to elucidate this question, CYP2D6 activity will be measured on healthy volunteers by administration of single low doses of dextromethorphan and tramadol in presence or not of duloxetine and paroxetine, two known CYP2D6 inhibitors.

Who can participate

Age range

18 Years – 60 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Healthy men and women * Age 18-60 years * Body Mass Index 18-27 * Understanding of French language and able to give a written inform consent * CYP2D6 genotype : combination of two fully-functional (normal activity) alleles or of one fully-functional and one non-functional allele (null activity), according to table 1, without gene multiplication Exclusion Criteria: * Pregnant or breastfeeding woman * Any pathologies, use of drugs or food that may affect CYP2D6 activity * Regular smokers of \>5 cigarettes/day * Renal or hepatic impairment * Medical history of chronic alcoholism or abuse of psychoactive drugs, including opiate addiction * Liver transplantation * Sensitivity to any of the drugs used * Alteration of hepatic tests more than 2x normal * Glomerular filtration rate \< 60 ml/min/1.73m2

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Difference in the proportion of volunteers with urinary metabolic ratio Dextromethorphan/Dextrorphan >0.3

Timeframe: 10 hours

Trial details

NCT IDNCT03054220

SponsorJules Desmeules

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2018-12

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