Kinetics of Yohimbine in Humans to Explore Sex and CYP2D6 Genotype Interactions (NCT06939608) | Clinical Trial Compass
CompletedNot Applicable
Kinetics of Yohimbine in Humans to Explore Sex and CYP2D6 Genotype Interactions
Germany36 participantsStarted 2025-04-28
Plain-language summary
This study investigates the pharmacokinetics of yohimbine in women and men aged 18 to 40 years to explore sex-specific differences in CYP2D6-dependent drug metabolism. Participants will be classified by their CYP2D6 genotype into extensive metabolizers (EM) and poor metabolizers (PM), forming four distinct study arms:
Arm 1) Women, Poor Metabolizers (PM) n=13 Arm 2) Women, Extensive Metabolizers (EM) n=5 Arm 3) Men, Poor Metabolizers (PM) n=13 Arm 4) Men, Extensive Metabolizers (EM) n=5
Each study arm will receive a single oral dose of 50 µg yohimbine (2 x 1 tablets, 25 µg per tablet) and 25 mg of ¹³C₃-caffeine co-administered as a drinking solution.
The purpose of this study is:
1. To characterize the pharmacokinetics of yohimbine following a single oral dose in women and men across different CYP2D6 phenotypes.
2. To evaluate yohimbine's suitability as a reliable probe for assessing CYP2D6 activity.
3. To investigate potential interactions between CYP2D6 and CYP1A2, as well as interindividual variability in CYP1A2-dependent caffeine metabolism.
Who can participate
Age range18 Years – 40 Years
SexALL
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Inclusion criteria
✓. individuals of both biological sexes, assigned as women or men at birth
✓. age: ≥ 18 and ≤ 40 years
✓. possesses the ability to understand the study purpose and design
✓. contractually capable and provides signed informed consent form
✓. in good general health or with mild and/or well-managed conditions such as allergies, asthma, hypertension or orthopedic diseases
✓. taking no more than three chronic medications
✓. individuals classified as either extensive metabolizers (EM) or poor metabolizers (PM) based on their CYP2D6 genotype:
Exclusion criteria
✕. BMI \> 30 kg/m2 and \< 18 kg/m2
✕. body weight \< 48 kg
✕. women: known pregnancy or lactation period; positive urine pregnancy test at screening or kinetic visit
What they're measuring
1
Yohimbine plasma concentration expressed as area under the curve (AUCâ‚€-â‚‚â‚„h) - arm 1 vs. arm 3
Timeframe: 24 hours
2
Yohimbine plasma concentration expressed as area under the curve (AUCâ‚€-â‚‚â‚„h) - arm 1 vs. arm 2
Timeframe: 24 hours
3
Yohimbine plasma concentration expressed as area under the curve (AUCâ‚€-â‚‚â‚„h) - arm 3 vs. arm 4
✕. elevated liver function tests (1 or more of ALAT, ASAT, yGT, Bilirubin \> 2x ULN)
✕. reduced renal function (eGFRMDRD \< 60 mL/min/1,7 m2)
✕. QTcF \> 450 ms in screening ECG
✕. current or recent psychiatric disorders requiring treatment including depression, bipolar disorder, schizophrenia, psychosis or severe anxiety disorders