MethamphetaminePhase 1NCT06746831
Methamphetamine Isomer Pharmacology in Humans
A Phase 1 study testing S-(+)-methamphetamine, R-(-)-methamphetamine and 1:1 racemic mixture of two isomers in people with Methamphetamine, run by University of Wisconsin, Madison at 1 site in United States.
Trial summary
This study is being done to understand the metabolism and impairment profile of methamphetamine (meth). Meth exists as two chemical structures that are mirror images of each other: R-meth and S-meth. S-meth is a strong central nervous system stimulant and used to treat attention deficit disorder (ADD). Read more about this study
- Who is it for?
- Ages 21 to 64 yearsHealthy volunteers can take part
- Conditions the study is for
- Methamphetamine
- What is being tested?
- S-(+)-methamphetamine, R-(-)-methamphetamine and 1:1 racemic mixture of two isomers
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 17 participants
- Where
- 1 siteUnited States
- Study dates
- Jan 2027to Jan 2029
- Phase
- Phase 1
- 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 21 to 64 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Good mental health as determined by self-reported responses to the Psychopathology Screener
- Absence of any major cardiac, neurologic, psychiatric, oncologic, endocrine, metabolic, renal, or hepatic disease as determined by self-reported responses to the Medical History Screener
- English-speaking (able to provide consent and complete questionnaires)
- Written Informed Consent
Who cannot join
- Any serious prior adverse response to sympathomimetic agents or amphetamine analogs
- History of or current substance use disorder as determined by self-reported responses to the Internalizing, Externalizing, and Substance Use Disorder Screener
- Pregnancy or lactation (pregnancy test, if needed)
- Use of medications that may impact cognition or metabolism (e.g., mood stabilizers, sedatives)
- Dependent on prohibited concomitant therapy that cannot be withheld for 48 hours prior to and during study visits.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: The Low-Down on Methamphetamine Isomers: Prevalence and Pharmacology in Humans
This study is being done to understand the metabolism and impairment profile of methamphetamine (meth). Meth exists as two chemical structures that are mirror images of each other: R-meth and S-meth. S-meth is a strong central nervous system stimulant and used to treat attention deficit disorder (ADD). R-meth is not a strong central nervous system stimulant and is available over-the-counter in nasal decongestant sprays.17 healthy participants will be enrolled for 3 study visits and on study for up to 12 weeks.
Read the detailed description
Double-blind crossover study design. Healthy volunteers will attend three study drug administration visits, at least 7 days apart, in which methamphetamine isomer pharmacology will be assessed following intravenous administration of (1) S-(+)-methamphetamine, (2) R(-)-methamphetamine, or (3) a (1:1) racemic mixture of R-(-)- and S-(+)-methamphetamine. The order of these interventions will be counterbalanced across participants. Serial blood samples will be drawn during each dosing visit and compared with concurrent dried blood spots from a finger stick, oral fluid collections, and pooled urine specimens.
Primary Objective
- Characterize the pharmacokinetics of acute S-(+)-methamphetamine administration.
- Characterize the pharmacokinetics of acute R-(-)-methamphetamine administration.
- Characterize the pharmacokinetics of acute racemic (1:1) R-(-)- and S-(+)-methamphetamine administration.
Secondary Objectives
- Assess for evidence of stereo-selective metabolic pathways.
- Assess for evidence of subjective, cognitive, or physiological effects from acute R-(-)-methamphetamine administration.
- Assess for evidence of more than additive effects when administering racemic methamphetamine.
Correlative Objectives
- Compare biological methamphetamine and metabolite concentrations in surveyed biological matrices (i.e., plasma, whole blood, oral fluid, dried capillary blood spots, and urine) over time.
- Compare cognitive and subjective effects of acute S-(+)-methamphetamine, R-(-)-methamphetamine, and racemic methamphetamine administration.
- Conditions
- Methamphetamine
- Being tested
- S-(+)-methamphetamine, R-(-)-methamphetamine, 1:1 racemic mixture of two isomers
- Keywords
- pharmacology, meth, isomers
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
S-(+)-methamphetamineDrug
Also called S-Meth
15 mg
R-(-)-methamphetamineDrug
Also called R-Meth
15 mg
1:1 racemic mixture of two isomersDrug
15 mg R-Meth + 15 mg S-Meth
| Study group | Role | What they receive |
|---|---|---|
| S-Meth, R-Meth, Racemic Isomer | Experimental | First visit: Administer S-Meth, then at least 7 days later Second visit: Administer R-Meth, then at least 7 days later Third visit: Administer (1:1) racemic methamphetamine Receives: Drug: S-(+)-methamphetamine; Drug: R-(-)-methamphetamine; Drug: 1:1 racemic mixture of two isomers |
| R-Meth, Racemic Isomer, S-Meth | Experimental | First visit: Administer R-Meth, then at least 7 days later Second visit: Administer (1:1) racemic methamphetamine, then at least 7 days later Third visit: Administer S-Meth Receives: Drug: S-(+)-methamphetamine; Drug: R-(-)-methamphetamine; Drug: 1:1 racemic mixture of two isomers |
| Racemic Isomer, S-Meth, R-Meth | Experimental | First visit: Administer (1:1) racemic methamphetamine, then at least 7 days later Second visit: Administer S-Meth, then at least 7 days later Third visit: Administer R-Meth Receives: Drug: S-(+)-methamphetamine; Drug: R-(-)-methamphetamine; Drug: 1:1 racemic mixture of two isomers |
What is being measured
The primary outcome is the main question the study is designed to answer.
Peak concentration (Cmax)
The pharmacokinetic analysis relies on observed drug and metabolite concentration measurements over time and across biological matrices (plasma, whole blood, dried capillary spots, oral fluid, urine) included in this study.
Measured: pre-dose, 0, 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 10, 12, 16, 20, 24, 30, 36, 42, 48 hours
Area under the concentration versus time curve (AUC)
The pharmacokinetic analysis relies on observed drug and metabolite concentration measurements over time and across biological matrices (plasma, whole blood, dried capillary spots, oral fluid, urine) included in this study.
Measured: pre-dose, 0, 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 10, 12, 16, 20, 24, 30, 36, 42, 48 hours
Secondary outcomes (5)
Cognitive Effects: Divided Attention Task (DAT)
The DAT requires participants track a moving stimulus on a computer screen while simultaneously monitoring numbers located in the corners of the screen. Participants must respond to target numbers as they appear, and the task quantifies mean distance of the mouse cursor from the center of the target stimulus.
Measured: Visit 1 (baseline), Visit 2 (week 1), Visit 3 (week 2)
Cognitive Effects: Digital Symbol Substitution Task (DSST)
The DSST asks participants to recreate patterns of various shapes presented on a computer screen using the keyboard. The total number of correct patterns are recorded within 90 seconds.
Measured: Visit 1 (baseline), Visit 2 (week 1), Visit 3 (week 2)
Cognitive Effects: Paced Serial Addition Task (PASAT)
The PASAT has participants view a string of single-digit numbers and calculate the sum of the two most recently presented numbers. The total number of correct trials out of 90 will be recorded.
Measured: Visit 1 (baseline), Visit 2 (week 1), Visit 3 (week 2)
Subjective Effects: Drug Effect Questionnaire (DEQ)
Subjective current general effects will be measured by asking the participant to rate if they feel the drug effect, if they like/dislike the drug effect, if they feel high, and if they would like more of the drug. Effects will be measured on a scale from "not at all" anchored at 0 to "extremely" at 100.
Measured: Visit 1 (baseline), Visit 2 (week 1), Visit 3 (week 2)
Subjective Effects: Number of Participants Who Answer 'True' for Amphetamine-specific questions
Participants will be asked 11 amphetamine-specific questions including feelings of pleasantness, excitability, memory, emptiness, body tingling, weird feeling, patience, and mental sharpness. Results are measured as either "true" (experiencing the specific state) or "false" (not experiencing the specific state). Number of participants who answered 'True' is reported here
Measured: Visit 1 (baseline), Visit 2 (week 1), Visit 3 (week 2)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Dec 2024
- Study startJan 2027 (estimated)
- Primary completionJan 2029 (estimated)
- Study completionJan 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for MethamphetamineStudies of the same condition, open and under way.
- More trials run by University of Wisconsin, MadisonThe sponsor's other registered studies.
- 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
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Double-blind crossover study design.
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 17 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Wisconsin, Madison
- Sponsor type
- University, hospital or other
- Collaborators
- U.S. Department of Justice
- Responsible party
- Sponsor
- Investigators
- Heather K Barkholtz, PhD, Principal investigator, University of Wisconsin, MadisonDavid Leinweber, MD, Principal investigator, University of Wisconsin, Madison
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06746831
- Sponsor's protocol ID
- 2024-1164
- Other IDs
- Protocol Version 2/12/25, A523000
- Status last verified
- Aug 2026
- First submitted
- 9 Dec 2024
- Last updated
- 3 Nov 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Low-Down on Methamphetamine Isomers: Prevalence and Pharmacology in Humans
- ClinicalTrials.gov ID
- NCT06746831
- Acronym / sponsor ID
- 2024-1164
- Conditions
- Methamphetamine
- Keywords
- pharmacology, meth, isomers
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 17 participants (estimated)
- Lead sponsor
- University of Wisconsin, MadisonUniversity, hospital or other
- Collaborators
- U.S. Department of Justice
- Study start
- Jan 2027 (estimated)
- Primary completion
- Jan 2029 (estimated)
- Study completion
- Jan 2029 (estimated)
- First posted
- 24 Dec 2024 (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 study is being done to understand the metabolism and impairment profile of methamphetamine (meth). Meth exists as two chemical structures that are mirror images of each other: R-meth and S-meth. S-meth is a strong central nervous system stimulant and used to treat attention deficit disorder (ADD). R-meth is not a strong central nervous system stimulant and is available over-the-counter in nasal decongestant sprays.17 healthy participants will be enrolled for 3 study visits and on study for up to 12 weeks.
Detailed description
Double-blind crossover study design. Healthy volunteers will attend three study drug administration visits, at least 7 days apart, in which methamphetamine isomer pharmacology will be assessed following intravenous administration of (1) S-(+)-methamphetamine, (2) R(-)-methamphetamine, or (3) a (1:1) racemic mixture of R-(-)- and S-(+)-methamphetamine. The order of these interventions will be counterbalanced across participants. Serial blood samples will be drawn during each dosing visit and compared with concurrent dried blood spots from a finger stick, oral fluid collections, and pooled urine specimens.
Primary Objective
- Characterize the pharmacokinetics of acute S-(+)-methamphetamine administration.
- Characterize the pharmacokinetics of acute R-(-)-methamphetamine administration.
- Characterize the pharmacokinetics of acute racemic (1:1) R-(-)- and S-(+)-methamphetamine administration.
Secondary Objectives
- Assess for evidence of stereo-selective metabolic pathways.
- Assess for evidence of subjective, cognitive, or physiological effects from acute R-(-)-methamphetamine administration.
- Assess for evidence of more than additive effects when administering racemic methamphetamine.
Correlative Objectives
- Compare biological methamphetamine and metabolite concentrations in surveyed biological matrices (i.e., plasma, whole blood, oral fluid, dried capillary blood spots, and urine) over time.
- Compare cognitive and subjective effects of acute S-(+)-methamphetamine, R-(-)-methamphetamine, and racemic methamphetamine administration.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 3
- Model description
- Double-blind crossover study design.
| Arm | Type | Receives |
|---|---|---|
| S-Meth, R-Meth, Racemic Isomer | Experimental | Drug: S-(+)-methamphetamine, Drug: R-(-)-methamphetamine, Drug: 1:1 racemic mixture of two isomersFirst visit: Administer S-Meth, then at least 7 days later Second visit: Administer R-Meth, then at least 7 days later Third visit: Administer (1:1) racemic methamphetamine |
| R-Meth, Racemic Isomer, S-Meth | Experimental | Drug: S-(+)-methamphetamine, Drug: R-(-)-methamphetamine, Drug: 1:1 racemic mixture of two isomersFirst visit: Administer R-Meth, then at least 7 days later Second visit: Administer (1:1) racemic methamphetamine, then at least 7 days later Third visit: Administer S-Meth |
| Racemic Isomer, S-Meth, R-Meth | Experimental | Drug: S-(+)-methamphetamine, Drug: R-(-)-methamphetamine, Drug: 1:1 racemic mixture of two isomersFirst visit: Administer (1:1) racemic methamphetamine, then at least 7 days later Second visit: Administer S-Meth, then at least 7 days later Third visit: Administer R-Meth |
Who may qualify
- Ages
- 21 to 64 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Good mental health as determined by self-reported responses to the Psychopathology Screener
- Absence of any major cardiac, neurologic, psychiatric, oncologic, endocrine, metabolic, renal, or hepatic disease as determined by self-reported responses to the Medical History Screener
- English-speaking (able to provide consent and complete questionnaires)
- Written Informed Consent
Key exclusion criteria (5 listed)
- Any serious prior adverse response to sympathomimetic agents or amphetamine analogs
- History of or current substance use disorder as determined by self-reported responses to the Internalizing, Externalizing, and Substance Use Disorder Screener
- Pregnancy or lactation (pregnancy test, if needed)
- Use of medications that may impact cognition or metabolism (e.g., mood stabilizers, sedatives)
- Dependent on prohibited concomitant therapy that cannot be withheld for 48 hours prior to and during study visits.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| S-(+)-methamphetamineAlso: S-Meth15 mg | Drug | R-Meth, Racemic Isomer, S-Meth, Racemic Isomer, S-Meth, R-Meth, S-Meth, R-Meth, Racemic Isomer |
| R-(-)-methamphetamineAlso: R-Meth15 mg | Drug | R-Meth, Racemic Isomer, S-Meth, Racemic Isomer, S-Meth, R-Meth, S-Meth, R-Meth, Racemic Isomer |
| 1:1 racemic mixture of two isomers15 mg R-Meth + 15 mg S-Meth | Drug | R-Meth, Racemic Isomer, S-Meth, Racemic Isomer, S-Meth, R-Meth, S-Meth, R-Meth, Racemic Isomer |
Primary outcome
Peak concentration (Cmax)
Time frame: pre-dose, 0, 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 10, 12, 16, 20, 24, 30, 36, 42, 48 hours
The pharmacokinetic analysis relies on observed drug and metabolite concentration measurements over time and across biological matrices (plasma, whole blood, dried capillary spots, oral fluid, urine) included in this study.
Area under the concentration versus time curve (AUC)
Time frame: pre-dose, 0, 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 10, 12, 16, 20, 24, 30, 36, 42, 48 hours
The pharmacokinetic analysis relies on observed drug and metabolite concentration measurements over time and across biological matrices (plasma, whole blood, dried capillary spots, oral fluid, urine) included in this study.
5 secondary outcomes
Cognitive Effects: Divided Attention Task (DAT)
Time frame: Visit 1 (baseline), Visit 2 (week 1), Visit 3 (week 2)
Cognitive Effects: Digital Symbol Substitution Task (DSST)
Time frame: Visit 1 (baseline), Visit 2 (week 1), Visit 3 (week 2)
Cognitive Effects: Paced Serial Addition Task (PASAT)
Time frame: Visit 1 (baseline), Visit 2 (week 1), Visit 3 (week 2)
Subjective Effects: Drug Effect Questionnaire (DEQ)
Time frame: Visit 1 (baseline), Visit 2 (week 1), Visit 3 (week 2)
Subjective Effects: Number of Participants Who Answer 'True' for Amphetamine-specific questions
Time frame: Visit 1 (baseline), Visit 2 (week 1), Visit 3 (week 2)
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 3 Nov 2026.
- Individual participant dataSharing planned: No
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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.
Heather K Barkholtz, PhD principal investigator
University of Wisconsin, Madison
David Leinweber, MD principal investigator
University of Wisconsin, Madison
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing S-(+)-methamphetamine, R-(-)-methamphetamine and 1:1 racemic mixture of two isomers in people with Methamphetamine, run by University of Wisconsin, Madison at 1 site in United States.
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 4 inclusion and 5 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 3 Nov 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 United States. 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.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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 Heather Barkholtz, PhD (608-890-1967, hbarkholtz@wisc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Peak concentration (Cmax) (time frame: pre-dose, 0, 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 10, 12, 16, 20, 24, 30, 36, 42, 48 hours). 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?
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 3 Nov 2026.