Behavioral Effects of Drugs (Inpatient): 40 [Methamphetamine, Methylphenidate, Duloxetine]

A Novel Drug Combination as a Pharmacotherapeutic for Methamphetamine-Use Disorder

Status

Completed

Phases

Phase 1

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT04178993

Enrollment

Registered

2019-11-26

Start date

2019-09-01

Completion date

2021-05-05

Last updated

2023-01-09

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Methamphetamine Use Disorder

Keywords

Methamphetamine, Methylphenidate, Duloxetine Hydrochloride, Central Nervous System Stimulants, Physiological Effects of Drugs, Dopamine Uptake Inhibitors, Serotonin and Noradrenaline Reuptake Inhibitors, Membrane Transport Modulators, Neurotransmitter Agents, Dopamine Agents, Molecular Mechanisms of Pharmacological Action, Sensory System Agents, Peripheral Nervous System Agents, Vasoconstrictor Agents, Antidepressive Agents, Psychotropic Drugs

Brief summary

This study will evaluate the behavioral effects of methamphetamine during maintenance on placebo, duloxetine, methylphenidate and duloxetine combined with methylphenidate using sophisticated human laboratory methods.

Interventions

DRUGDuloxetine

Subjects will receive duloxetine capsules in the duloxetine arm.

DRUGMethamphetamine

In each arm, subjects will receive doses of methamphetamine.

DRUGMethylphenidate

In each arm, subjects will receive methylphenidate capsules.

DRUGPlacebo oral capsule

In each arm, subjects will receive placebo capsules.

Study design

Allocation

RANDOMIZED

Intervention model

FACTORIAL

Primary purpose

BASIC_SCIENCE

Masking

TRIPLE (Subject, Caregiver, Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Age

18 Years to 55 Years

Healthy volunteers

Yes

Inclusion criteria

* recent use of inhaled (i.e., snorted), smoked or injected methamphetamine

Exclusion criteria

* Abnormal screening outcome (e.g., ECG, blood chemistry result) that study physicians deem clinically significant. * Current or past histories of substance use that are deemed by the study physicians to interfere with study completion. * History of serious physical disease, current physical disease, impaired cardiovascular functioning, chronic obstructive pulmonary disease, history of seizure or current or past histories of serious psychiatric disorder that in the opinion of the study physician would interfere with study participation will be excluded from participation. * Females not currently using effective birth control. * Contraindications to methamphetamine, methylphenidate, or duloxetine.

Design outcomes

Primary

Measure	Time frame	Description
Reinforcing Effects of Methamphetamine Following Methylphenidate (60 mg) Maintenance.	Following at least 4 days of maintenance on drug during inpatient admission, up to 1 week	Number of methamphetamine doses earned by subjects on a progressive ratio schedule of reinforcement. Subjects sample a dose of methamphetamine (0, 10, or 20 mg) and then have the ten opportunities (e.g., trials) to work for a 1/10th of the sampled dose via clicking on a computer mouse (i.e., 10 completed trials is the full sampled dose).
Reinforcing Effects of Methamphetamine Following Methylphenidate (40 mg) Maintenance.	Following at least 4 days of maintenance on drug during inpatient admission, up to 1 week	Number of methamphetamine doses earned by subjects on a progressive ratio schedule of reinforcement. Subjects sample a dose of methamphetamine (0, 10, or 20 mg) and then have the ten opportunities (e.g., trials) to work for a 1/10th of the sampled dose via clicking on a computer mouse (i.e., 10 completed trials is the full sampled dose).
Reinforcing Effects of Methamphetamine Following Methylphenidate (0 mg; Placebo) Maintenance.	Following at least 4 days of maintenance on placebo during inpatient admission, up to 1 week	Number of methamphetamine doses earned by subjects on a progressive ratio schedule of reinforcement. Subjects sample a dose of methamphetamine (0, 10, or 20 mg) and then have ten opportunities (e.g., trials) to work for a 1/10th of the sampled dose via clicking on a computer mouse (i.e., 10 completed trials is the full sampled dose).
Reinforcing Effects of Methamphetamine Following Methylphenidate (20 mg) Maintenance.	Following at least 4 days of maintenance on drug during inpatient admission, up to 1 week	Number of methamphetamine doses earned by subjects on a progressive ratio schedule of reinforcement. Subjects sample a dose of methamphetamine (0, 10, or 20 mg) and then have the ten opportunities (e.g., trials) to work for a 1/10th of the sampled dose via clicking on a computer mouse (i.e., 10 completed trials is the full sampled dose).

Secondary

Measure	Time frame	Description
Heart Rate After Methamphetamine Administration Following Methylphenidate (60 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Heart Rate (beats per minute) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)
Systolic Blood Pressure After Methamphetamine Administration Following Methylphenidate (0 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Systolic blood pressure (millimeter of mercury) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)
Systolic Blood Pressure After Methamphetamine Administration Following Methylphenidate (20 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Systolic blood pressure (millimeter of mercury) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)
Systolic Blood Pressure After Methamphetamine Administration Following Methylphenidate (40 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Systolic blood pressure (millimeter of mercury) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)
Systolic Blood Pressure After Methamphetamine Administration Following Methylphenidate (60 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Systolic blood pressure (millimeter of mercury) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)
Diastolic Blood Pressure After Methamphetamine Administration Following Methylphenidate (0 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Diastolic blood pressure (millimeter of mercury) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)
Diastolic Blood Pressure After Methamphetamine Administration Following Methylphenidate (20 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Diastolic blood pressure (millimeter of mercury) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)
Diastolic Blood Pressure After Methamphetamine Administration Following Methylphenidate (40 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Diastolic blood pressure (millimeter of mercury) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)
Diastolic Blood Pressure After Methamphetamine Administration Following Methylphenidate (60 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Diastolic blood pressure (millimeter of mercury) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)
Temperature After Methamphetamine Administration Following Methylphenidate (0 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Oral temperature (degrees fahrenheit) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)
Temperature After Methamphetamine Administration Following Methylphenidate (20 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Oral temperature (degrees fahrenheit) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)
Temperature After Methamphetamine Administration Following Methylphenidate (60 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Oral temperature (degrees fahrenheit) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)
Subjective Effects of Methamphetamine (0 mg) Administration Following Methylphenidate (0 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Subjective effects (i.e., mood) of methamphetamine are recorded following administration. Data are presented as mean peak effect. Peak effect means the highest rated value (0 - 100 mm) following administration of methamphetamine.
Subjective Effects of Methamphetamine (10 mg) Administration Following Methylphenidate (0 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Subjective effects (i.e., mood) of methamphetamine are recorded following administration. Data are presented as mean peak effect. Peak effect means the highest rated value (0 - 100 mm) following administration of methamphetamine.
Subjective Effects of Methamphetamine (20 mg) Administration Following Methylphenidate (0 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Subjective effects (i.e., mood) of methamphetamine are recorded following administration. Data are presented as mean peak effect. Peak effect means the highest rated value (0 - 100 mm) following administration of methamphetamine.
Subjective Effects of Methamphetamine (0 mg) Administration Following Methylphenidate (20 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Subjective effects (i.e., mood) of methamphetamine are recorded following administration. Data are presented as mean peak effect. Peak effect means the highest rated value (0 - 100 mm) following administration of methamphetamine.
Subjective Effects of Methamphetamine (10 mg) Administration Following Methylphenidate (20 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Subjective effects (i.e., mood) of methamphetamine are recorded following administration. Data are presented as mean peak effect. Peak effect means the highest rated value (0 - 100 mm) following administration of methamphetamine.
Subjective Effects of Methamphetamine (20 mg) Administration Following Methylphenidate (20 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Subjective effects (i.e., mood) of methamphetamine are recorded following administration. Data are presented as mean peak effect. Peak effect means the highest rated value (0 - 100 mm) following administration of methamphetamine.
Subjective Effects of Methamphetamine (0 mg) Administration Following Methylphenidate (40 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Subjective effects (i.e., mood) of methamphetamine are recorded following administration. Data are presented as mean peak effect. Peak effect means the highest rated value (0 - 100 mm) following administration of methamphetamine.
Subjective Effects of Methamphetamine (10 mg) Administration Following Methylphenidate (40 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Subjective effects (i.e., mood) of methamphetamine are recorded following administration. Data are presented as mean peak effect. Peak effect means the highest rated value (0 - 100 mm) following administration of methamphetamine.
Subjective Effects of Methamphetamine (20 mg) Administration Following Methylphenidate (40 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Subjective effects (i.e., mood) of methamphetamine are recorded following administration. Data are presented as mean peak effect. Peak effect means the highest rated value (0 - 100 mm) following administration of methamphetamine.
Subjective Effects of Methamphetamine (0 mg) Administration Following Methylphenidate (60 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Subjective effects (i.e., mood) of methamphetamine are recorded following administration. Data are presented as mean peak effect. Peak effect means the highest rated value (0 - 100 mm) following administration of methamphetamine.
Subjective Effects of Methamphetamine (10 mg) Administration Following Methylphenidate (60 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Subjective effects (i.e., mood) of methamphetamine are recorded following administration. Data are presented as mean peak effect. Peak effect means the highest rated value (0 - 100 mm) following administration of methamphetamine.
Subjective Effects of Methamphetamine (20 mg) Administration Following Methylphenidate (60 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Subjective effects (i.e., mood) of methamphetamine are recorded following administration. Data are presented as mean peak effect. Peak effect means the highest rated value (0 - 100 mm) following administration of methamphetamine.
Temperature After Methamphetamine Administration Following Methylphenidate (40 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Oral temperature (degrees fahrenheit) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)
Heart Rate After Methamphetamine Administration Following Methylphenidate (0 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Heart Rate (beats per minute) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)
Heart Rate After Methamphetamine Administration Following Methylphenidate (20 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Heart Rate (beats per minute) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)
Heart Rate After Methamphetamine Administration Following Methylphenidate (40 mg) Maintenance.	Daily over approximately 1 week of inpatient stay.	Heart Rate (beats per minute) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)

Other

Measure	Time frame	Description
Attentional Bias	12 sessions over approximately 4.5 weeks	Subjects will complete an attentional bias task. The number of inhibitory failures (i.e., commission errors) to no-go targets following methamphetamine-related stimuli will be used to evaluate attentional bias (range 0 - 1: greater values represent greater number of errors committed). Commission errors are when you response (i.e., press the corresponding key on a computer) when you were instructed not to respond.
Delay Discounting for Money	4 sessions over approximately 4.5 weeks	Subjects will complete a delay discounting task in 4 sessions following 4 days of medication maintenance. Subjects are presented a series of hypothetical choices between a smaller sum of money offered now or a larger sum of money offered a later times in the future (e.g., 4 hours, a day, 3 weeks). The discounting rate, 'k', is calculated and log10-transformed. Greater values of log-transformed 'k' correspond with greater rates of discounting (i.e., preference for smaller reinforcer provided now rather than larger, delayed reinforcers \[e.g., smaller sum of money given now as opposed to a larger sum given later\]). The units for discounting rates are theoretical and not linked to a physical dimension (e.g., number of button presses) and the range is theoretically not bound (i.e., negative infinity to positive infinity).
Delay Discounting for Methamphetamine	4 sessions over approximately 4.5 weeks	Subjects will complete a delay discounting task in 4 sessions following 4 days of medication maintenance. Subjects are presented a series of hypothetical choices between a smaller amount of methamphetamine offered now or a larger amount of methamphetamine offered a later times in the future (e.g., 4 hours, a day, 3 weeks). The discounting rate, 'k', is calculated and log10-transformed. Greater values of log-transformed 'k' correspond with greater rates of discounting (i.e., preference for smaller reinforcer provided now rather than larger, delayed reinforcers \[e.g., smaller amount of methamphetamine given now as opposed to a larger amount given later\]). The units for discounting rates are theoretical and not linked to a physical dimension (e.g., number of button presses) and the range is theoretically not bound (i.e., negative infinity to positive infinity).
Snaith-Hamilton-Pleasure Scale to Measure Anhedonia (Inability to Experience Pleasure)	4 times over approximately 4.5 weeks	A 14-item Snaith-Hamilton-Pleasure Scale covers four domains of pleasure response (interest/pastimes, social interaction, sensory experience and food/drink) with higher scores representing less anhedonia. Scores range from 0 to 56 units: lower scores representing greater anhedonia.

Countries

United States

Participant flow

Participants by arm

Arm	Count
Placebo Comparator: Placebo Subjects will be maintained on oral placebo. Subjects will be maintained on placebo and methylphenidate during placebo maintenance. Methamphetamine will be administered acutely during placebo maintenance. Placebo will be administered acutely during placebo maintenance. Methamphetamine: In each arm, subjects will receive doses of methamphetamine. Methylphenidate: In each arm, subjects will receive methylphenidate capsules. Placebo oral capsule: In each arm, subjects will receive placebo capsules.	4
Active Comparator: Duloxetine Subjects will be maintained on oral duloxetine. Subjects will be maintained on duloxetine and methylphenidate during placebo maintenance. Methamphetamine will be administered acutely during duloxetine maintenance. Placebo will be administered acutely during duloxetine maintenance. Methamphetamine: In each arm, subjects will receive doses of methamphetamine. Methylphenidate: In each arm, subjects will receive methylphenidate capsules. Placebo oral capsule: In each arm, subjects will receive placebo capsules. Duloxetine: Subjects will receive duloxetine capsules in the duloxetine arm.	4
Total	8

Baseline characteristics

Characteristic	Active Comparator: Duloxetine	Total	Placebo Comparator: Placebo
Age, Categorical <=18 years	0 Participants	0 Participants	0 Participants
Age, Categorical >=65 years	0 Participants	0 Participants	0 Participants
Age, Categorical Between 18 and 65 years	4 Participants	8 Participants	4 Participants
Age, Continuous	41.5 Years STANDARD_DEVIATION 13.11	39.75 Years STANDARD_DEVIATION 11.07	38 Years STANDARD_DEVIATION 13.08
Race (NIH/OMB) American Indian or Alaska Native	0 Participants	0 Participants	0 Participants
Race (NIH/OMB) Asian	0 Participants	0 Participants	0 Participants
Race (NIH/OMB) Black or African American	0 Participants	1 Participants	1 Participants
Race (NIH/OMB) More than one race	0 Participants	1 Participants	1 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants	0 Participants	0 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants	0 Participants	0 Participants
Race (NIH/OMB) White	4 Participants	6 Participants	2 Participants
Region of Enrollment United States	4 Participants	8 Participants	4 Participants
Sex: Female, Male Female	1 Participants	1 Participants	0 Participants
Sex: Female, Male Male	3 Participants	7 Participants	4 Participants

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk
deaths Total, all-cause mortality	0 / 3	0 / 4
other Total, other adverse events	2 / 3	2 / 4
serious Total, serious adverse events	0 / 3	0 / 4

Outcome results

Primary

Reinforcing Effects of Methamphetamine Following Methylphenidate (0 mg; Placebo) Maintenance.

Number of methamphetamine doses earned by subjects on a progressive ratio schedule of reinforcement. Subjects sample a dose of methamphetamine (0, 10, or 20 mg) and then have ten opportunities (e.g., trials) to work for a 1/10th of the sampled dose via clicking on a computer mouse (i.e., 10 completed trials is the full sampled dose).

Time frame: Following at least 4 days of maintenance on placebo during inpatient admission, up to 1 week

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo Comparator: Placebo	Reinforcing Effects of Methamphetamine Following Methylphenidate (0 mg; Placebo) Maintenance.	Methamphetamine (0mg)	0 Trials Completed	Standard Deviation 0
Placebo Comparator: Placebo	Reinforcing Effects of Methamphetamine Following Methylphenidate (0 mg; Placebo) Maintenance.	Methamphetamine (10mg)	3.33 Trials Completed	Standard Deviation 5.77
Placebo Comparator: Placebo	Reinforcing Effects of Methamphetamine Following Methylphenidate (0 mg; Placebo) Maintenance.	Methamphetamine (20mg)	10 Trials Completed	Standard Deviation 0
Active Comparator: Duloxetine (60 mg)	Reinforcing Effects of Methamphetamine Following Methylphenidate (0 mg; Placebo) Maintenance.	Methamphetamine (10mg)	7.25 Trials Completed	Standard Deviation 4.86
Active Comparator: Duloxetine (60 mg)	Reinforcing Effects of Methamphetamine Following Methylphenidate (0 mg; Placebo) Maintenance.	Methamphetamine (0mg)	0 Trials Completed	Standard Deviation 0
Active Comparator: Duloxetine (60 mg)	Reinforcing Effects of Methamphetamine Following Methylphenidate (0 mg; Placebo) Maintenance.	Methamphetamine (20mg)	9.75 Trials Completed	Standard Deviation 0.5

Primary

Reinforcing Effects of Methamphetamine Following Methylphenidate (20 mg) Maintenance.

Number of methamphetamine doses earned by subjects on a progressive ratio schedule of reinforcement. Subjects sample a dose of methamphetamine (0, 10, or 20 mg) and then have the ten opportunities (e.g., trials) to work for a 1/10th of the sampled dose via clicking on a computer mouse (i.e., 10 completed trials is the full sampled dose).

Time frame: Following at least 4 days of maintenance on drug during inpatient admission, up to 1 week

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo Comparator: Placebo	Reinforcing Effects of Methamphetamine Following Methylphenidate (20 mg) Maintenance.	Methamphetamine (0mg)	0 Trials Completed	Standard Deviation 0
Placebo Comparator: Placebo	Reinforcing Effects of Methamphetamine Following Methylphenidate (20 mg) Maintenance.	Methamphetamine (10mg)	6.67 Trials Completed	Standard Deviation 5.77
Placebo Comparator: Placebo	Reinforcing Effects of Methamphetamine Following Methylphenidate (20 mg) Maintenance.	Methamphetamine (20mg)	8.00 Trials Completed	Standard Deviation 3.46
Active Comparator: Duloxetine (60 mg)	Reinforcing Effects of Methamphetamine Following Methylphenidate (20 mg) Maintenance.	Methamphetamine (0mg)	2.50 Trials Completed	Standard Deviation 5
Active Comparator: Duloxetine (60 mg)	Reinforcing Effects of Methamphetamine Following Methylphenidate (20 mg) Maintenance.	Methamphetamine (10mg)	7.00 Trials Completed	Standard Deviation 4.69
Active Comparator: Duloxetine (60 mg)	Reinforcing Effects of Methamphetamine Following Methylphenidate (20 mg) Maintenance.	Methamphetamine (20mg)	9.75 Trials Completed	Standard Deviation 0.5

Primary

Reinforcing Effects of Methamphetamine Following Methylphenidate (40 mg) Maintenance.

Time frame: Following at least 4 days of maintenance on drug during inpatient admission, up to 1 week

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo Comparator: Placebo	Reinforcing Effects of Methamphetamine Following Methylphenidate (40 mg) Maintenance.	Methamphetamine (0mg)	1.67 Trials Completed	Standard Deviation 2.89
Placebo Comparator: Placebo	Reinforcing Effects of Methamphetamine Following Methylphenidate (40 mg) Maintenance.	Methamphetamine (10mg)	10 Trials Completed	Standard Deviation 0
Placebo Comparator: Placebo	Reinforcing Effects of Methamphetamine Following Methylphenidate (40 mg) Maintenance.	Methamphetamine (20mg)	10 Trials Completed	Standard Deviation 0
Active Comparator: Duloxetine (60 mg)	Reinforcing Effects of Methamphetamine Following Methylphenidate (40 mg) Maintenance.	Methamphetamine (0mg)	0 Trials Completed	Standard Deviation 0
Active Comparator: Duloxetine (60 mg)	Reinforcing Effects of Methamphetamine Following Methylphenidate (40 mg) Maintenance.	Methamphetamine (10mg)	5.00 Trials Completed	Standard Deviation 5.77
Active Comparator: Duloxetine (60 mg)	Reinforcing Effects of Methamphetamine Following Methylphenidate (40 mg) Maintenance.	Methamphetamine (20mg)	10 Trials Completed	Standard Deviation 0

Primary

Reinforcing Effects of Methamphetamine Following Methylphenidate (60 mg) Maintenance.

Time frame: Following at least 4 days of maintenance on drug during inpatient admission, up to 1 week

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo Comparator: Placebo	Reinforcing Effects of Methamphetamine Following Methylphenidate (60 mg) Maintenance.	Methamphetamine (0mg)	2.33 Trials Completed	Standard Deviation 4.04
Placebo Comparator: Placebo	Reinforcing Effects of Methamphetamine Following Methylphenidate (60 mg) Maintenance.	Methamphetamine (10mg)	3.33 Trials Completed	Standard Deviation 5.77
Placebo Comparator: Placebo	Reinforcing Effects of Methamphetamine Following Methylphenidate (60 mg) Maintenance.	Methamphetamine (20mg)	10 Trials Completed	Standard Deviation 0
Active Comparator: Duloxetine (60 mg)	Reinforcing Effects of Methamphetamine Following Methylphenidate (60 mg) Maintenance.	Methamphetamine (0mg)	0 Trials Completed	Standard Deviation 0
Active Comparator: Duloxetine (60 mg)	Reinforcing Effects of Methamphetamine Following Methylphenidate (60 mg) Maintenance.	Methamphetamine (10mg)	7.50 Trials Completed	Standard Deviation 5
Active Comparator: Duloxetine (60 mg)	Reinforcing Effects of Methamphetamine Following Methylphenidate (60 mg) Maintenance.	Methamphetamine (20mg)	9.75 Trials Completed	Standard Deviation 0.5

Secondary

Diastolic Blood Pressure After Methamphetamine Administration Following Methylphenidate (0 mg) Maintenance.

Diastolic blood pressure (millimeter of mercury) is recorded following administration of methamphetamine. Data are presented as mean peak effect. Peak effect means the highest rated value following administration of methamphetamine (0, 10, and 20 mg)