Trial Outcomes & Findings for Risky Decision Making in Methamphetamine Users: The Role of Opioid Blockade (NCT NCT01822132)

NCT ID: NCT01822132

Last Updated: 2019-03-05

Results Overview

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.

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 76 participants
• Primary outcome timeframe: 28 days post drug intervention
• Results posted on: 2019-03-05

Participant Flow

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)

Participant milestones

Measure	Naltrexone One dose of intramuscular injection of 380mg extended-release naltrexone.	Placebo One dose of intramuscular injection of placebo.
Overall Study STARTED	25	27
Overall Study COMPLETED	21	25
Overall Study NOT COMPLETED	4	2

Reasons for withdrawal

Measure	Naltrexone One dose of intramuscular injection of 380mg extended-release naltrexone.	Placebo One dose of intramuscular injection of placebo.
Overall Study Lost to Follow-up	4	2

Baseline Characteristics

Risky Decision Making in Methamphetamine Users: The Role of Opioid Blockade

Baseline characteristics by cohort

Measure	Extended Release Naltrexone n=25 Participants One dose of intramuscular injection of 380mg extended-release naltrexone. Extended release naltrexone	Placebo n=27 Participants One dose of intramuscular injection of placebo. Placebo	Total n=52 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	25 Participants n=5 Participants	27 Participants n=7 Participants	52 Participants n=5 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Sex: Female, Male Female	6 Participants n=5 Participants	8 Participants n=7 Participants	14 Participants n=5 Participants
Sex: Female, Male Male	19 Participants n=5 Participants	19 Participants n=7 Participants	38 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	2 Participants n=5 Participants	4 Participants n=7 Participants	6 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	23 Participants n=5 Participants	23 Participants n=7 Participants	46 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants
Race (NIH/OMB) White	23 Participants n=5 Participants	25 Participants n=7 Participants	48 Participants n=5 Participants
Race (NIH/OMB) More than one race	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	2 Participants n=7 Participants	2 Participants n=5 Participants
Region of Enrollment United States	25 participants n=5 Participants	27 participants n=7 Participants	52 participants n=5 Participants

PRIMARY outcome

Timeframe: 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.

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.

Outcome measures

Measure	Naltrexone n=21 Participants Participants who were randomized to naltrexone.	Placebo n=25 Participants Participants who were randomized to receive placebo.
Discounting Tasks: Sexual Probability Discounting (SexPD) Baseline_All	2.97 natural log Standard Deviation 11.07	6.52 natural log Standard Deviation 8.52
Discounting Tasks: Sexual Probability Discounting (SexPD) Post_HIV-negative	6.55 natural log Standard Deviation 13.39	9.79 natural log Standard Deviation 13.38
Discounting Tasks: Sexual Probability Discounting (SexPD) Post_All	4.68 natural log Standard Deviation 12.07	7.67 natural log Standard Deviation 11.74
Discounting Tasks: Sexual Probability Discounting (SexPD) Post_HIV-positive	-0.54 natural log Standard Deviation 5.16	1.08 natural log Standard Deviation 2.84

PRIMARY outcome

Timeframe: 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.

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).

Outcome measures

Measure	Naltrexone n=21 Participants Participants who were randomized to naltrexone.	Placebo n=25 Participants Participants who were randomized to receive placebo.
Discounting Tasks: Standard Delay Discounting (DD) Baseline_All	-2.92 natural log Standard Deviation 6.06	-3.90 natural log Standard Deviation 2.04
Discounting Tasks: Standard Delay Discounting (DD) Post_All	-2.73 natural log Standard Deviation 7.76	-4.25 natural log Standard Deviation 1.65
Discounting Tasks: Standard Delay Discounting (DD) Post_HIV-positive	-5.44 natural log Standard Deviation 1.48	-5.56 natural log Standard Deviation 1.61
Discounting Tasks: Standard Delay Discounting (DD) Post_HIV-negative	-1.57 natural log Standard Deviation 9.08	-3.88 natural log Standard Deviation 1.50

PRIMARY outcome

Timeframe: 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.

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.

Outcome measures

Measure	Naltrexone n=21 Participants Participants who were randomized to naltrexone.	Placebo n=25 Participants Participants who were randomized to receive placebo.
Barrat Impulsiveness Scale (BIS) Baseline_All	77.5 score on a scale Standard Deviation 14.24	73.52 score on a scale Standard Deviation 13.16
Barrat Impulsiveness Scale (BIS) Post_All	71.79 score on a scale Standard Deviation 10.07	63.30 score on a scale Standard Deviation 11.53
Barrat Impulsiveness Scale (BIS) Post_HIV-positive	70.83 score on a scale Standard Deviation 7.49	61 score on a scale Standard Deviation 13.15
Barrat Impulsiveness Scale (BIS) Post_HIV-negative	72.23 score on a scale Standard Deviation 11.31	64.47 score on a scale Standard Deviation 11.70

PRIMARY outcome

Timeframe: 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.

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.

Outcome measures

Measure	Naltrexone n=21 Participants Participants who were randomized to naltrexone.	Placebo n=25 Participants Participants who were randomized to receive placebo.
Risk Assessment Battery (RAB) DrugRisk_Post_All	0.24 score on a scale Standard Deviation 0.54	0.08 score on a scale Standard Deviation 0.40
Risk Assessment Battery (RAB) SexRisk_Baseline_All	5.48 score on a scale Standard Deviation 3.23	4.44 score on a scale Standard Deviation 3.16
Risk Assessment Battery (RAB) SexRisk_Post_All	4.81 score on a scale Standard Deviation 2.75	4.72 score on a scale Standard Deviation 2.89
Risk Assessment Battery (RAB) TotalRisk_Baseline_All	0.17 score on a scale Standard Deviation 0.12	0.13 score on a scale Standard Deviation 0.09
Risk Assessment Battery (RAB) TotalRisk_Post_All	0.13 score on a scale Standard Deviation 0.07	0.12 score on a scale Standard Deviation 0.07
Risk Assessment Battery (RAB) DrugRisk_Baseline_HIV-positive	1 score on a scale Standard Deviation 1.67	0.17 score on a scale Standard Deviation 0.41
Risk Assessment Battery (RAB) DrugRisk_Post_HIV-positive	0 score on a scale Standard Deviation 0	0 score on a scale Standard Deviation 0
Risk Assessment Battery (RAB) SexRisk_Baseline_HIV-positive	6.5 score on a scale Standard Deviation 4.04	5.17 score on a scale Standard Deviation 2.64
Risk Assessment Battery (RAB) SexRisk_Post_HIV-positive	5.83 score on a scale Standard Deviation 3.76	4.17 score on a scale Standard Deviation 1.83
Risk Assessment Battery (RAB) TotalRisk_Baseline_HIV-positive	0.19 score on a scale Standard Deviation 0.08	0.13 score on a scale Standard Deviation 0.06
Risk Assessment Battery (RAB) TotalRisk_Post_HIV-positive	0.15 score on a scale Standard Deviation 0.094	0.10 score on a scale Standard Deviation 0.05
Risk Assessment Battery (RAB) DrugRisk_Baseline_HIV-negative	1.47 score on a scale Standard Deviation 3.34	0.74 score on a scale Standard Deviation 2.13
Risk Assessment Battery (RAB) DrugRisk_Post_HIV-negative	0.33 score on a scale Standard Deviation 0.62	0.11 score on a scale Standard Deviation 0.46
Risk Assessment Battery (RAB) SexRisk_Baseline_HIV-negative	5.07 score on a scale Standard Deviation 2.91	4.21 score on a scale Standard Deviation 3.34
Risk Assessment Battery (RAB) SexRisk_Post_HIV-negative	4.4 score on a scale Standard Deviation 2.26	4.89 score on a scale Standard Deviation 3.18
Risk Assessment Battery (RAB) TotalRisk_Baseline_HIV-negative	0.16 score on a scale Standard Deviation 0.13	0.12 score on a scale Standard Deviation 0.095
Risk Assessment Battery (RAB) TotalRisk_Post_HIV-negative	0.12 score on a scale Standard Deviation 0.055	0.13 score on a scale Standard Deviation 0.081
Risk Assessment Battery (RAB) DrugRisk_Baseline_All	1.33 score on a scale Standard Deviation 2.92	0.6 score on a scale Standard Deviation 1.87

SECONDARY outcome

Timeframe: 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.

Participants were asked "How many days in the past 30 days did you use methamphetamine?". This is a self-report measure.

Outcome measures

Measure	Naltrexone n=21 Participants Participants who were randomized to naltrexone.	Placebo n=25 Participants Participants who were randomized to receive placebo.
Methamphetamine Use Post_All	1.33 days Standard Deviation 3.23	2.17 days Standard Deviation 5.52
Methamphetamine Use Post_HIV-positive	1.17 days Standard Deviation 1.83	1.6 days Standard Deviation 3.58
Methamphetamine Use Post_HIV-negative	1.4 days Standard Deviation 3.70	0.13 days Standard Deviation 0.52

Adverse Events

Extended Release Naltrexone

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Placebo

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Todd Korthuis

Oregon Health & Science University

Phone: 503-494-8044

Email: korthuis@ohsu.edu

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place