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A Study To Evaluate The Abuse Potential Of Single Oral Doses Of Dimebon (Latrepirdine) In Healthy Recreational Polydrug Users

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT00975481
First Posted: September 11, 2009
Last Update Posted: April 2, 2013
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Collaborator:
Medivation, Inc.
Information provided by (Responsible Party):
Pfizer
  Purpose
Dimebon will not exhibit abuse potential when compared to placebo or a positive control (alprazolam).

Condition Intervention Phase
Alzheimer's Disease Huntington's Disease Drug: dimebon Drug: placebo Drug: alprazolam Phase 1

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double (Participant, Investigator)
Official Title: A Randomized, Double-Blind, Placebo- And Active-Controlled Single-Dose, Crossover Study To Evaluate The Abuse Potential Of Single Doses Of Dimebon (Latrepirdine) In Healthy Recreational Polydrug Users

Resource links provided by NLM:


Further study details as provided by Pfizer:

Primary Outcome Measures:
  • Balance of Effects- Drug Liking VAS: Peak Effect (Maximum Effect [Emax]) and Minimum Effect (Emin) [ Time Frame: 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose ]

    Drug liking VAS is one of the measures of balance of effects that assesses the degree that a participant likes a drug effect at the time the question is being asked (that is, at the moment). It is scored using a 100 millimeter (mm) bipolar visual analogue scale (VAS) anchored in the center with a neutral anchor of "neither like nor dislike" (score of 50 mm), on the left with "strong disliking" (score of 0 mm) and on the right with "strong liking" (score of 100 mm).

    Emax is largest effect score between 0.5 to 24 hours post-dose. Emin is smallest effect score between 0.5 to 24 hours post-dose.


  • Balance of Effects- Overall Drug Liking VAS: Peak Effect (Maximum Effect [Emax]) and Minimum Effect (Emin) [ Time Frame: 6, 12, 24 hours post-dose ]

    Overall drug liking VAS is one of the measures of balance of effects that assesses the participant's global perception of drug liking (that is, effects over the whole course of the drug experience including any carryover effects). A 100 mm bipolar VAS is used to assess response based on a score ranging from 0 mm to 100 mm (0 mm = "strong disliking", 50 mm= "neither like nor dislike", and 100 mm= "strong liking").

    Emax is the largest effect score between 6 to 24 hours post-dose. Emin is the smallest effect score between 6 to 24 hours post-dose.


  • Balance of Effects- Take Drug Again VAS: Peak Effect (Maximum Effect [Emax]) [ Time Frame: 6, 12, 24 hours post-dose ]

    Take drug again VAS is one of the measures of balance of effects. It is a subjective assessment of the degree to which a participant would desire to take the drug again if given the opportunity. It is presented on a 100 mm bipolar VAS with score ranging from 0 mm to 100 mm (score of 0 mm = "definitely not", 50 mm = "do not care", and 100 mm = "definitely so").

    Emax is largest effect score between 6 hours to 24 hours.


  • Balance of Effects- Good and Bad Effects VAS: Peak Effect (Maximum Effect [Emax]) and Minimum Effect (Emin) [ Time Frame: 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose ]

    Good and Bad effects VAS is one of the measures of balance of effects that assesses the effect experienced by the participant on a 100 mm bipolar VAS, anchored in the center with a neutral anchor of neither good nor bad effects (score of 50 mm), on the left with bad effects(score of 0 mm) and on the right with good effects (score of 100 mm).

    Emax is largest effect score between 0.5 to 24 hours post-dose. Emin is smallest effect score between 0.5 to 24 hours post-dose.


  • Balance of Effects- Subjective Drug Value (SDV): Maximum Effect (Emax) [ Time Frame: 6, 12, 24 hrs post-dose ]
    SDV is one of measures of balance of effects. It is a proxy measure of reinforcing efficacy that involves a series of independent, theoretical forced choices between drug administered and different monetary values. Participants were asked to choose between receiving another dose of same drug or an envelope containing specified amount of money, but they did not receive drug or money as described. Possible score range from 0.25 to 50. Higher score range indicates higher SDV. Emax: largest effect score between 6-24 hours post-dose.

  • Positive Effects- Addiction Research Center Inventory (ARCI) Morphine Benzedrine Group (MBG): Maximum Effect (Emax) [ Time Frame: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8 12, 24 hours post-dose ]
    ARCI (MBG) is one of the measures of positive effects. It is a set of 16 questions in which each question contributes to total score. Participants indicate their responses by selecting 'False' or 'True'. One point is given for each response that agrees with the scoring direction on scale i.e, 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 the answer is opposite to the scoring direction. Score range: 0 to 16, higher score indicated positive effects. Emax: largest effect score between 0 to 24 hours post-dose.

  • Positive Effects- Good Drug Effects: Peak Effect (Maximum Effect [Emax]) [ Time Frame: 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose ]

    Good drug effects VAS is one of the measures of positive effects that assesses the effect experienced by the participant on a 100 mm unipolar VAS, where responses are unidirectional and range from a response of 'none' (score of 0 mm= definitely not) to 'extremely' (score of 100 mm= definitely so).

    Emax is the largest effect score between 0.5 to 24 hours post-dose.


  • Positive Effects- High VAS: Peak Effect (Maximum Effect [Emax]) [ Time Frame: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose ]

    High VAS is one of the measures of positive effects that assesses the effect experienced by the participant on a 100 mm unipolar VAS, where responses are unidirectional and range from a response of 'none' (score of 0 mm= definitely not) to 'extremely' (score of 100 mm= definitely so).

    Emax is largest effect score between 0 to 24 hours.


  • Negative Effects- Bad Drug Effects: Peak Effect (Maximum Effect [Emax]) [ Time Frame: 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose ]

    Bad effects VAS is one of the measures of negative effects that assesses the effect experienced by the participant on a 100 mm unipolar VAS, where responses are unidirectional and range from a response of 'none' (score of 0 mm= definitely not) to 'extremely' (score of 100 mm= definitely so).

    Emax is largest effect score between 0.5 to 24 hrs.


  • Negative Effects- Addiction Research Center Inventory (ARCI) Lysergic Acid Diethylamide (LSD): Maximum Effect (Emax) [ Time Frame: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose ]
    ARCI (LSD) is one of the measures of negative effects. It is a set of 14 questions in which each question contributes to total score. Participants indicate their responses by selecting 'False' or 'True'. One point is given for each response that agrees with scoring direction on scale i.e, 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 the answer is opposite to scoring direction. Score range: 0 to 14, higher score indicated higher negative effects. Emax: largest effect score between 0 to 24 hours post-dose.

  • Sedative Effects- Addiction Research Center Inventory (ARCI) Pentobarbital Chlorpromazine Group (PCAG): Maximum Effect (Emax) [ Time Frame: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose ]
    ARCI (PCAG) is one of the measures of sedative effects. It is a set of 15 questions in which each question contributes to total score. Participants indicate their responses by selecting 'False' or 'True'. One point is given for each response that agrees with the scoring direction on scale i.e, 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. Score range: 0 to 15, higher score indicated higher sedative effects. Emax: largest effect score between 0 to 24 hours post-dose.

  • Sedative Effects- Alertness/Drowsiness: Minimum Effect (Emin) [ Time Frame: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose ]
    Alertness/Drowsiness VAS is one of the measures of sedative effects. It is scored using a 100 mm bipolar VAS anchored in the center with a neutral anchor of "neither drowsy nor alert" (score of 50 mm), on the left with "very drowsy" (score of 0 mm) and on the right with "very alert" (score of 100 mm). Emin is the smallest effect score between 0 to 24 hours post-dose.

  • Other Subjective Effects- Any Drug Effects: Peak Effect (Maximum Effect [Emax]) [ Time Frame: 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose ]
    Any drug effects VAS is one of the measures of other subjective effects. It assesses the effect experienced by the participant on a 100 mm unipolar VAS, where responses are unidirectional and range from a response of 'none' (score of 0 mm= definitely not) to 'extremely' (score of 100 mm= definitely so). Emax is the largest effect score between 0.5 to 24 hours post-dose.

  • Other Subjective Effects- Drug Similarity [ Time Frame: 12 hours post-dose ]
    Drug similarity VAS is one of the measures of other subjective effects. It assesses the similarity of the drug recently received by the participant on a 100 mm unipolar VAS, where responses are unidirectional and range from a response of 'none' (score of 0 mm= not at all similar) to 'extremely' (score of 100 mm= very similar). Recently received drugs were compared with placebo, benzodiazepines, codeine/morphine, Tetrahydrocannabinol (THC), pseudoephedrine.

  • Other Subjective Effects- Addiction Research Center Inventory (ARCI) Benzedrine Group (BG): Maximum Effect (Emax) and Minimum Effect (Emin) [ Time Frame: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose ]
    ARCI (BG) is measure of other subjective effects. It is a set of 13 questions in which each question contributes to total score. Participants select 'False' / 'True' for response. One point given for each response that agrees with scoring direction, true items receive score of 1 if answer 'True', false items receive score of 1 if answer 'False'. No points if answer is opposite to scoring direction. Score range: 0 to 13, higher score indicated higher other subjective effects. Emax: largest effect score between 0 - 24 hours post-dose. Emin: smallest effect score between 0 - 24 hours post-dose.


Enrollment: 36
Study Start Date: October 2009
Study Completion Date: February 2010
Primary Completion Date: February 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: dimebon 20 mg Drug: dimebon
Oral tablet; 20 mg dimebon, single dose
Experimental: dimebon 40 mg Drug: dimebon
Oral tablet; 40 mg dimebon, single dose
Experimental: dimebon 60 mg Drug: dimebon
Oral tablet; 60 mg dimebon, single dose
Placebo Comparator: placebo Drug: placebo
Oral tablet or capsule; placebo, single dose
Active Comparator: alprazolam 1 mg Drug: alprazolam
Oral capsule; 1 mg alprazolam, single dose
Active Comparator: alprazolam 3 mg Drug: alprazolam
Oral capsule; 3 mg alprazolam, single dose

Detailed Description:
The main purpose for this study is to determine whether dimebon exhibits abuse potential.
  Eligibility

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


Ages Eligible for Study:   18 Years to 55 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Healthy male and/or female subjects between the ages of 18 and 55 years.
  • Recreational polydrug user with a history of CNS depressant use.

Exclusion Criteria:

  • History of clinically significant neurologic condition(s), such as seizures, convulsions, epilepsy, or significant head injury, as judged by the investigator or designee.
  • A known history of hypersensitivity or previous intolerance to dimebon or other antihistamines.
  • Self-reported history of drug or alcohol dependence (except nicotine or caffeine) in the 2 years prior to screening, or drug or alcohol dependence as defined by the (DSM-IV-TR) in 12 months prior to screening, including subjects who have ever been in a substance rehabilitation program (other than treatment for smoking cessation).
  • History of clinically significant psychiatric disorder(s), as judged by the investigator or qualified designee.
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00975481


Sponsors and Collaborators
Pfizer
Medivation, Inc.
Investigators
Study Director: Pfizer CT.gov Call Center Pfizer
  More Information

Additional Information:
Responsible Party: Pfizer
ClinicalTrials.gov Identifier: NCT00975481     History of Changes
Other Study ID Numbers: B1451037
First Submitted: September 10, 2009
First Posted: September 11, 2009
Results First Submitted: December 3, 2012
Results First Posted: April 2, 2013
Last Update Posted: April 2, 2013
Last Verified: February 2013

Keywords provided by Pfizer:
oral single-dose 6-way crossover recreational drug users abuse potential pharmacodynamics safety

Additional relevant MeSH terms:
Alzheimer Disease
Huntington Disease
Dementia
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Tauopathies
Neurodegenerative Diseases
Neurocognitive Disorders
Mental Disorders
Basal Ganglia Diseases
Chorea
Dyskinesias
Movement Disorders
Heredodegenerative Disorders, Nervous System
Genetic Diseases, Inborn
Cognition Disorders
Alprazolam
Hypnotics and Sedatives
Central Nervous System Depressants
Physiological Effects of Drugs
Anti-Anxiety Agents
Tranquilizing Agents
Psychotropic Drugs
GABA Modulators
GABA Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action