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.
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 Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
17
15 mg
15 mg
15 mg R-Meth + 15 mg S-Meth
University of Wisconsin
Madison, Wisconsin, United States
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.
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
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.
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
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.
Time frame: 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.
Time frame: 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.
Time frame: Visit 1 (baseline), Visit 2 (week 1), Visit 3 (week 2)
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
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.
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
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
Time frame: Visit 1 (baseline), Visit 2 (week 1), Visit 3 (week 2)