Pilot Study of Entacapone for Methamphetamine Abuse

Early Phase 1CompletedNCT02058966

Oregon Health and Science University29 enrolled

Overview

Addiction to methamphetamine is a serious health problem. There are no medications that a doctor can give someone to help them stop using methamphetamine. Entacapone (Comtan©) is a medication that could help people addicted to methamphetamine. This study will see how entacapone works in healthy people who are given methamphetamine. We think that the study drug will be well tolerated, and that it will prevent some of the effects of methamphetamine that make it so addictive. We also want to see how differences in people's genes may cause differences in the ways the study drug and methamphetamine work for them. The study has six total visits. The first visit is for screening. Tests and procedures will make sure it is safe for subjects to participate. The second visit is a familiarization day. Subjects will receive methamphetamine, but no entacapone. This is done to make sure they can tolerate the drug and recognize its effects before being given a second drug on the same day. Subjects will take surveys and computer tests to see how the medications change mood, thinking, and liking the drug. The final four visits are the actual study days. Subjects will be randomly assigned (like the flip of a coin) to the different ways to get either 1) study medication or placebo (placebo contains no active study medication) and then 2) methamphetamine or placebo. Subjects will be in all four groups during the study, which means that each day a subject will get a different group.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

HEALTH_SERVICES_RESEARCH

Masking

QUADRUPLE

Enrollment

Conditions

Methamphetamine Dependence

Eligibility

Sex: ALLMin age: 18 YearsMax age: 45 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * No history of pre-existing physical (including cardiovascular) illness * No history of drug abuse or dependence * Ability to read and write English * Have had at least one exposure to a stimulant (e.g. cocaine, methamphetamine, ecstasy, methylphenidate or any medication in the stimulant class) in their lifetime Exclusion Criteria: * Pregnant * Taking any psychotropic medication * Meeting DSM-IV criteria for active substance abuse or dependence * On any stimulant medication * History or current hypertension (BP \> 140/90 mm Hg) or systolic hypotension (SBP \< 90 mm Hg) * Subjects with resting pulse rate \> 90/min * Any active medical illness * Family history of abnormal heart rhythms, or sudden cardiac death * Subjects who anticipate they may require the emergent use of epinephrine (such as an Epi-Pen®) for the treatment of severe allergic reactions

Outcomes

Primary Outcomes

Effect of Entacapone on Methamphetamine-induced Mood

Profile of Mood States is a 65 item questionnaire using a Likert rating scale to assess transient, distinct moods. The questionnaire contains 65 words/statements that describe feelings people have. The test requires you to indicate for each word or statement how you have been feeling in the past week including today. A Total Mood Disturbance score is calculated by adding scores for Tension, Depression, Anger, Fatigue and Confusion and then subtracting the Vigour score. The Total Mood Disturbance scale ranges from -32 to 200 with lower scores indicative of people with more stable mood profiles.

Time frame: Measurements acquired before drug ingestion (baseline) then hourly for 4 hours. The peak interaction effect of entacapone and methamphetamine occurs 1 hour after ingestion, therefore the reported values are from this timepoint.

Effect of Entacapone on Subjective Effects of Methamphetamine

The subjective effects of the study drug were evaluated with the Addiction Research Center Inventory (ARCI-49), a 49 item questionnaire consisting of true/false items. True items receive a score of 1 if answer is 'True', false items receive a score of 1 if answer is 'False'. No points are given when answer is opposite to scoring direction. There are 5 subscales: Morphine Benzedrine group scale to measure euphoria (range: 0-16 with higher numbers indicating more euphoria), A Lysergic Acid Diethylamide group scale to estimate dysphoria and agitation (range: 0-14 with higher scores indicating more dysphoria), a Pentobarbital Chlorpromazine Alcohol group scale to measure sedation (range: 0-15 with higher scores indicating more sedation), and a Benzedrine group scale and an Amphetamine Scale to assess stimulant effects (range: 0-13 and 0-11, respectively, with higher scores indicating higher stimulant effects) .

Effect of Entacapone on Methamphetamine-induced Stimulation

The Global Rating of Stimulation is a 1-item question "I feel light-headed, restless, or speeded-up" in which the participant is asked to circle one answer on a scale from 0-4, 0 is 'normal', 1 is 'slightly', 2 is 'moderately', 3 is 'very much', and 4 is 'extremely'. Whichever number they circled is their reported score. A higher score is indicative of a greater stimulating effect.

Secondary Outcomes

Cognitive Function

Two computer tests were administered to measure how each medication intervention effects cognitive functioning. The tests administered included the Rapid Visual Information Processing Task (RVIPT), a 6 minute test of sustained attention in which participants are requested to detect target sequences of digits and the Digit Symbol Substitution Task (DSST), a 2 minute test of psychomotor speed and sustained attention consisting of digit-symbol pairs followed by a list of digits where the subject identifies the symbol that corresponds to each digit as fast as possible. The number of correct responses within the allowed time is measured. Higher scores on both tasks indicate better performance.