Methamphetamine Abuse, HIV
Conditions
Brief summary
The purpose of this protocol is to learn more about impulsive decision making in people who use methamphetamines. The investigators would like to know if a medication called naltrexone changes how people make decisions. The investigators would also like to know whether changes in decision making can be observed by MRI (magnetic resonance imaging). The research is conducted in Portland, OR.
Interventions
DRUGPlacebo
Sponsors
National Institute on Drug Abuse (NIDA)
Oregon Health and Science University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
TRIPLE (Subject, Caregiver, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
No
Inclusion criteria
Summary Inclusion Criteria: * Diagnostic and Statistical Manual (DSM)-IV Methamphetamine Dependence * Deemed healthy enough to participate by study physician * Age 18-55 * Right handed * English-speaking Summary
Exclusion criteria
* Current opioid use in the last 30 days; opioid abuse or dependence within past 5 years * Pregnancy * MRI contraindications (e.g. metal in head). The research is conducted in Portland, OR.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Discounting Tasks: Sexual Probability Discounting (SexPD) | 28 days post drug intervention | In the SexPD task, subjects are asked to choose between having sex with a more appealing partner with a varying chance of having a sexually transmitted infection (STI) or a less appealing partner with no STI. A hyperbolic decay model was used to calculate h, a free parameter that indexes the rate of probabilistic discounting. Smaller h values indicate a preference for probabilistic (i.e., riskier) outcomes. To normalize the data, the natural log of h values were calculated and reported here. |
| Discounting Tasks: Standard Delay Discounting (DD) | 28 days post drug intervention | Monetary delay discounting task consisted of choosing between a larger, delayed and a smaller, immediate reward. A hyperbolic decay model was used to calculate k, a free parameter that indexes the rate of delay discounting. As k values are typically skewed across subjects, the distribution of k was normalized by using a natural log transformation. The normalized values are reported here. If k typically ranges between 0.5 and 10\^-5, then the natural log of k will range between -0.69 and -11.5. Larger normalized k values indicate a preference for smaller sooner outcomes (i.e., more impulsive decision-making). |
| Barrat Impulsiveness Scale (BIS) | 28 days post drug intervention | The Barrat Impulsiveness Scale (BIS) is a 30 item questionnaire to measure a persons impulsiveness. Items are answered on a 4-point scale and scored 1-4 then summed across responses. Total scores range from 30-120 with a higher summed score indicating higher impulsivity. |
| Risk Assessment Battery (RAB) | 28 days post drug intervention | The Risk Assessment Battery (RAB) is a 26 question self-administered assessment focusing on drug use, injection and sexual risk during the past 30 days. Three composite HIV risk scores (drug, sex, and total score) are calculated. The questions have different numbers of items, and scores for a single question can range from 0 to 7, with higher values reflecting more instances of risk behavior. The drug risk score has a range of 0 to 22 and is calculated from 8 questions that address recent substance use, including frequency, needle sharing, and cleaning of the works. 9 questions are used to calculate a sex risk score that has a range of 0 to 18, and these questions address the frequency and types of sexual behavior, HIV status of sexual partners, and type of protection that was used (if any). Total score is calculated by adding drug and sex scores and dividing by 40, the maximum score possible, and ranges from 0 to 40 where higher scores indicate greater risk behavior. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Methamphetamine Use | 28 days post drug intervention | Participants were asked How many days in the past 30 days did you use methamphetamine?. This is a self-report measure. |
Countries
United States
Participant flow
Pre-assignment details
After consenting, 13 participants did not meet screening inclusion criteria and were removed from the study and 11 participants withdrew, leaving 52 eligible participants for randomization into a treatment group (Naltrexone or Placebo)
Participants by arm
| Arm | Count |
|---|---|
| Extended Release Naltrexone One dose of intramuscular injection of 380mg extended-release naltrexone.
Extended release naltrexone | 25 |
| Placebo One dose of intramuscular injection of placebo.
Placebo | 27 |
| Total | 52 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Lost to Follow-up | 4 | 2 |
Baseline characteristics
| Characteristic | Extended Release Naltrexone | Placebo | Total |
|---|---|---|---|
| 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 | 25 Participants | 27 Participants | 52 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 2 Participants | 4 Participants | 6 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 23 Participants | 23 Participants | 46 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| 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 | 1 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) More than one race | 1 Participants | 0 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 | 2 Participants | 2 Participants |
| Race (NIH/OMB) White | 23 Participants | 25 Participants | 48 Participants |
| Region of Enrollment United States | 25 participants | 27 participants | 52 participants |
| Sex: Female, Male Female | 6 Participants | 8 Participants | 14 Participants |
| Sex: Female, Male Male | 19 Participants | 19 Participants | 38 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 25 | 0 / 27 |
| serious Total, serious adverse events | 0 / 25 | 0 / 27 |
Outcome results
Primary
Barrat Impulsiveness Scale (BIS)
The Barrat Impulsiveness Scale (BIS) is a 30 item questionnaire to measure a persons impulsiveness. Items are answered on a 4-point scale and scored 1-4 then summed across responses. Total scores range from 30-120 with a higher summed score indicating higher impulsivity.
Time frame: 28 days post drug intervention
Population: Subjects with methamphetamine dependence and either HIV positive or not, all abstaining from opioids for at least 30 days.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Naltrexone | Barrat Impulsiveness Scale (BIS) | Baseline_All | 77.5 score on a scale | Standard Deviation 14.24 |
| Naltrexone | Barrat Impulsiveness Scale (BIS) | Post_HIV-positive | 70.83 score on a scale | Standard Deviation 7.49 |
| Naltrexone | Barrat Impulsiveness Scale (BIS) | Post_All | 71.79 score on a scale | Standard Deviation 10.07 |
| Naltrexone | Barrat Impulsiveness Scale (BIS) | Post_HIV-negative | 72.23 score on a scale | Standard Deviation 11.31 |
| Placebo | Barrat Impulsiveness Scale (BIS) | Post_All | 63.30 score on a scale | Standard Deviation 11.53 |
| Placebo | Barrat Impulsiveness Scale (BIS) | Post_HIV-negative | 64.47 score on a scale | Standard Deviation 11.7 |
| Placebo | Barrat Impulsiveness Scale (BIS) | Baseline_All | 73.52 score on a scale | Standard Deviation 13.16 |
| Placebo | Barrat Impulsiveness Scale (BIS) | Post_HIV-positive | 61 score on a scale | Standard Deviation 13.15 |
Primary
Discounting Tasks: Sexual Probability Discounting (SexPD)
In the SexPD task, subjects are asked to choose between having sex with a more appealing partner with a varying chance of having a sexually transmitted infection (STI) or a less appealing partner with no STI. A hyperbolic decay model was used to calculate h, a free parameter that indexes the rate of probabilistic discounting. Smaller h values indicate a preference for probabilistic (i.e., riskier) outcomes. To normalize the data, the natural log of h values were calculated and reported here.
Time frame: 28 days post drug intervention
Population: Subjects with methamphetamine dependence and either HIV positive or not, all abstaining from opioids for at least 30 days.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Naltrexone | Discounting Tasks: Sexual Probability Discounting (SexPD) | Post_HIV-positive | -0.54 natural log | Standard Deviation 5.16 |
| Naltrexone | Discounting Tasks: Sexual Probability Discounting (SexPD) | Post_All | 4.68 natural log | Standard Deviation 12.07 |
| Naltrexone | Discounting Tasks: Sexual Probability Discounting (SexPD) | Post_HIV-negative | 6.55 natural log | Standard Deviation 13.39 |
| Naltrexone | Discounting Tasks: Sexual Probability Discounting (SexPD) | Baseline_All | 2.97 natural log | Standard Deviation 11.07 |
| Placebo | Discounting Tasks: Sexual Probability Discounting (SexPD) | Post_HIV-negative | 9.79 natural log | Standard Deviation 13.38 |
| Placebo | Discounting Tasks: Sexual Probability Discounting (SexPD) | Post_All | 7.67 natural log | Standard Deviation 11.74 |
| Placebo | Discounting Tasks: Sexual Probability Discounting (SexPD) | Post_HIV-positive | 1.08 natural log | Standard Deviation 2.84 |
| Placebo | Discounting Tasks: Sexual Probability Discounting (SexPD) | Baseline_All | 6.52 natural log | Standard Deviation 8.52 |
Primary
Discounting Tasks: Standard Delay Discounting (DD)
Monetary delay discounting task consisted of choosing between a larger, delayed and a smaller, immediate reward. A hyperbolic decay model was used to calculate k, a free parameter that indexes the rate of delay discounting. As k values are typically skewed across subjects, the distribution of k was normalized by using a natural log transformation. The normalized values are reported here. If k typically ranges between 0.5 and 10\^-5, then the natural log of k will range between -0.69 and -11.5. Larger normalized k values indicate a preference for smaller sooner outcomes (i.e., more impulsive decision-making).
Time frame: 28 days post drug intervention
Population: Subjects with methamphetamine dependence and either HIV positive or not, all abstaining from opioids for at least 30 days.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Naltrexone | Discounting Tasks: Standard Delay Discounting (DD) | Baseline_All | -2.92 natural log | Standard Deviation 6.06 |
| Naltrexone | Discounting Tasks: Standard Delay Discounting (DD) | Post_All | -2.73 natural log | Standard Deviation 7.76 |
| Naltrexone | Discounting Tasks: Standard Delay Discounting (DD) | Post_HIV-positive | -5.44 natural log | Standard Deviation 1.48 |
| Naltrexone | Discounting Tasks: Standard Delay Discounting (DD) | Post_HIV-negative | -1.57 natural log | Standard Deviation 9.08 |
| Placebo | Discounting Tasks: Standard Delay Discounting (DD) | Post_HIV-negative | -3.88 natural log | Standard Deviation 1.5 |
| Placebo | Discounting Tasks: Standard Delay Discounting (DD) | Baseline_All | -3.90 natural log | Standard Deviation 2.04 |
| Placebo | Discounting Tasks: Standard Delay Discounting (DD) | Post_HIV-positive | -5.56 natural log | Standard Deviation 1.61 |
| Placebo | Discounting Tasks: Standard Delay Discounting (DD) | Post_All | -4.25 natural log | Standard Deviation 1.65 |
Primary
Risk Assessment Battery (RAB)
The Risk Assessment Battery (RAB) is a 26 question self-administered assessment focusing on drug use, injection and sexual risk during the past 30 days. Three composite HIV risk scores (drug, sex, and total score) are calculated. The questions have different numbers of items, and scores for a single question can range from 0 to 7, with higher values reflecting more instances of risk behavior. The drug risk score has a range of 0 to 22 and is calculated from 8 questions that address recent substance use, including frequency, needle sharing, and cleaning of the works. 9 questions are used to calculate a sex risk score that has a range of 0 to 18, and these questions address the frequency and types of sexual behavior, HIV status of sexual partners, and type of protection that was used (if any). Total score is calculated by adding drug and sex scores and dividing by 40, the maximum score possible, and ranges from 0 to 40 where higher scores indicate greater risk behavior.
Time frame: 28 days post drug intervention
Population: Subjects with methamphetamine dependence and either HIV positive or not, all abstaining from opioids for at least 30 days.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Naltrexone | Risk Assessment Battery (RAB) | SexRisk_Baseline_HIV-positive | 6.5 score on a scale | Standard Deviation 4.04 |
| Naltrexone | Risk Assessment Battery (RAB) | DrugRisk_Baseline_All | 1.33 score on a scale | Standard Deviation 2.92 |
| Naltrexone | Risk Assessment Battery (RAB) | DrugRisk_Post_All | 0.24 score on a scale | Standard Deviation 0.54 |
| Naltrexone | Risk Assessment Battery (RAB) | SexRisk_Baseline_All | 5.48 score on a scale | Standard Deviation 3.23 |
| Naltrexone | Risk Assessment Battery (RAB) | SexRisk_Post_All | 4.81 score on a scale | Standard Deviation 2.75 |
| Naltrexone | Risk Assessment Battery (RAB) | TotalRisk_Baseline_All | 0.17 score on a scale | Standard Deviation 0.12 |
| Naltrexone | Risk Assessment Battery (RAB) | TotalRisk_Post_All | 0.13 score on a scale | Standard Deviation 0.07 |
| Naltrexone | Risk Assessment Battery (RAB) | DrugRisk_Baseline_HIV-positive | 1 score on a scale | Standard Deviation 1.67 |
| Naltrexone | Risk Assessment Battery (RAB) | DrugRisk_Post_HIV-positive | 0 score on a scale | Standard Deviation 0 |
| Naltrexone | Risk Assessment Battery (RAB) | SexRisk_Post_HIV-positive | 5.83 score on a scale | Standard Deviation 3.76 |
| Naltrexone | Risk Assessment Battery (RAB) | TotalRisk_Baseline_HIV-positive | 0.19 score on a scale | Standard Deviation 0.08 |
| Naltrexone | Risk Assessment Battery (RAB) | TotalRisk_Post_HIV-positive | 0.15 score on a scale | Standard Deviation 0.094 |
| Naltrexone | Risk Assessment Battery (RAB) | DrugRisk_Baseline_HIV-negative | 1.47 score on a scale | Standard Deviation 3.34 |
| Naltrexone | Risk Assessment Battery (RAB) | DrugRisk_Post_HIV-negative | 0.33 score on a scale | Standard Deviation 0.62 |
| Naltrexone | Risk Assessment Battery (RAB) | SexRisk_Baseline_HIV-negative | 5.07 score on a scale | Standard Deviation 2.91 |
| Naltrexone | Risk Assessment Battery (RAB) | SexRisk_Post_HIV-negative | 4.4 score on a scale | Standard Deviation 2.26 |
| Naltrexone | Risk Assessment Battery (RAB) | TotalRisk_Baseline_HIV-negative | 0.16 score on a scale | Standard Deviation 0.13 |
| Naltrexone | Risk Assessment Battery (RAB) | TotalRisk_Post_HIV-negative | 0.12 score on a scale | Standard Deviation 0.055 |
| Placebo | Risk Assessment Battery (RAB) | DrugRisk_Post_HIV-negative | 0.11 score on a scale | Standard Deviation 0.46 |
| Placebo | Risk Assessment Battery (RAB) | SexRisk_Post_HIV-positive | 4.17 score on a scale | Standard Deviation 1.83 |
| Placebo | Risk Assessment Battery (RAB) | DrugRisk_Baseline_All | 0.6 score on a scale | Standard Deviation 1.87 |
| Placebo | Risk Assessment Battery (RAB) | TotalRisk_Post_HIV-negative | 0.13 score on a scale | Standard Deviation 0.081 |
| Placebo | Risk Assessment Battery (RAB) | DrugRisk_Post_All | 0.08 score on a scale | Standard Deviation 0.4 |
| Placebo | Risk Assessment Battery (RAB) | TotalRisk_Baseline_HIV-positive | 0.13 score on a scale | Standard Deviation 0.06 |
| Placebo | Risk Assessment Battery (RAB) | SexRisk_Baseline_All | 4.44 score on a scale | Standard Deviation 3.16 |
| Placebo | Risk Assessment Battery (RAB) | SexRisk_Baseline_HIV-negative | 4.21 score on a scale | Standard Deviation 3.34 |
| Placebo | Risk Assessment Battery (RAB) | SexRisk_Post_All | 4.72 score on a scale | Standard Deviation 2.89 |
| Placebo | Risk Assessment Battery (RAB) | TotalRisk_Post_HIV-positive | 0.10 score on a scale | Standard Deviation 0.05 |
| Placebo | Risk Assessment Battery (RAB) | TotalRisk_Baseline_All | 0.13 score on a scale | Standard Deviation 0.09 |
| Placebo | Risk Assessment Battery (RAB) | TotalRisk_Baseline_HIV-negative | 0.12 score on a scale | Standard Deviation 0.095 |
| Placebo | Risk Assessment Battery (RAB) | TotalRisk_Post_All | 0.12 score on a scale | Standard Deviation 0.07 |
| Placebo | Risk Assessment Battery (RAB) | DrugRisk_Baseline_HIV-negative | 0.74 score on a scale | Standard Deviation 2.13 |
| Placebo | Risk Assessment Battery (RAB) | DrugRisk_Baseline_HIV-positive | 0.17 score on a scale | Standard Deviation 0.41 |
| Placebo | Risk Assessment Battery (RAB) | SexRisk_Post_HIV-negative | 4.89 score on a scale | Standard Deviation 3.18 |
| Placebo | Risk Assessment Battery (RAB) | DrugRisk_Post_HIV-positive | 0 score on a scale | Standard Deviation 0 |
| Placebo | Risk Assessment Battery (RAB) | SexRisk_Baseline_HIV-positive | 5.17 score on a scale | Standard Deviation 2.64 |
Secondary
Methamphetamine Use
Participants were asked How many days in the past 30 days did you use methamphetamine?. This is a self-report measure.
Time frame: 28 days post drug intervention
Population: Subjects with methamphetamine dependence and either HIV positive or not, all abstaining from opioids for at least 30 days.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Naltrexone | Methamphetamine Use | Post_All | 1.33 days | Standard Deviation 3.23 |
| Naltrexone | Methamphetamine Use | Post_HIV-positive | 1.17 days | Standard Deviation 1.83 |
| Naltrexone | Methamphetamine Use | Post_HIV-negative | 1.4 days | Standard Deviation 3.7 |
| Placebo | Methamphetamine Use | Post_HIV-negative | 0.13 days | Standard Deviation 0.52 |
| Placebo | Methamphetamine Use | Post_All | 2.17 days | Standard Deviation 5.52 |
| Placebo | Methamphetamine Use | Post_HIV-positive | 1.6 days | Standard Deviation 3.58 |