Alzheimer's DiseasePhase 1NCT00975481

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

A Phase 1 study testing dimebon and alprazolam in people with Alzheimer's Disease and Huntington's Disease, run by Pfizer.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

Dimebon will not exhibit abuse potential when compared to placebo or a positive control (alprazolam). Read more about this study

Who is it for?: Ages 18 to 55 years
Conditions the study is for: Alzheimer's Disease, Huntington's Disease
What is being tested?: dimebon and alprazolam
Type of treatment: Pill or oral medicine
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 36 participants
Where: No sites listed yet
Study dates: Oct 2009to Feb 2010
Phase: Phase 1
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 to 55 years
All sexes
No healthy volunteers
Adult

Who may be able to join

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

Who cannot join

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.

About this study

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

Dimebon will not exhibit abuse potential when compared to placebo or a positive control (alprazolam).

Read the detailed description

The main purpose for this study is to determine whether dimebon exhibits abuse potential.

Conditions: Alzheimer's Disease, Huntington's Disease
Being tested: dimebon, placebo, alprazolam
Keywords: oral single-dose 6-way crossover recreational drug users abuse potential pharmacodynamics safety
Medical subject headings: Alzheimer Disease, Huntington Disease

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

dimebonDrug
Oral tablet; 20 mg dimebon, single dose
dimebonDrug
Oral tablet; 40 mg dimebon, single dose
dimebonDrug
Oral tablet; 60 mg dimebon, single dose
placeboDrug
Oral tablet or capsule; placebo, single dose
alprazolamDrug
Oral capsule; 1 mg alprazolam, single dose
alprazolamDrug
Oral capsule; 3 mg alprazolam, single dose

Study groups in NCT00975481
Study group	Role	What they receive
dimebon 20 mg	Experimental	Not described Receives: Drug: dimebon
dimebon 40 mg	Experimental	Not described Receives: Drug: dimebon
dimebon 60 mg	Experimental	Not described Receives: Drug: dimebon
placebo	Placebo comparator	Not described Receives: Drug: placebo
alprazolam 1 mg	Active comparator	Not described Receives: Drug: alprazolam
alprazolam 3 mg	Active comparator	Not described Receives: Drug: alprazolam

What is being measured

The primary outcome is the main question the study is designed to answer.

Balance of Effects- Drug Liking VAS: Peak Effect (Maximum Effect [Emax]) and Minimum Effect (Emin)
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.
Measured: 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose
Balance of Effects- Overall Drug Liking VAS: Peak Effect (Maximum Effect [Emax]) and Minimum Effect (Emin)
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.
Measured: 6, 12, 24 hours post-dose
Balance of Effects- Take Drug Again VAS: Peak Effect (Maximum Effect [Emax])
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.
Measured: 6, 12, 24 hours post-dose
Balance of Effects- Good and Bad Effects VAS: Peak Effect (Maximum Effect [Emax]) and Minimum Effect (Emin)
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.
Measured: 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose
Balance of Effects- Subjective Drug Value (SDV): Maximum Effect (Emax)
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.
Measured: 6, 12, 24 hrs post-dose
Positive Effects- Addiction Research Center Inventory (ARCI) Morphine Benzedrine Group (MBG): Maximum Effect (Emax)
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.
Measured: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8 12, 24 hours post-dose
Positive Effects- Good Drug Effects: Peak Effect (Maximum Effect [Emax])
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.
Measured: 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose
Positive Effects- High VAS: Peak Effect (Maximum Effect [Emax])
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.
Measured: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose
Negative Effects- Bad Drug Effects: Peak Effect (Maximum Effect [Emax])
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.
Measured: 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose
Negative Effects- Addiction Research Center Inventory (ARCI) Lysergic Acid Diethylamide (LSD): Maximum Effect (Emax)
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.
Measured: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose
Sedative Effects- Addiction Research Center Inventory (ARCI) Pentobarbital Chlorpromazine Group (PCAG): Maximum Effect (Emax)
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.
Measured: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose
Sedative Effects- Alertness/Drowsiness: Minimum Effect (Emin)
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.
Measured: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose
Other Subjective Effects- Any Drug Effects: Peak Effect (Maximum Effect [Emax])
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.
Measured: 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose
Other Subjective Effects- Drug Similarity
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.
Measured: 12 hours post-dose
Other Subjective Effects- Addiction Research Center Inventory (ARCI) Benzedrine Group (BG): Maximum Effect (Emax) and Minimum Effect (Emin)
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.
Measured: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, 12, 24 hours post-dose

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

Oct 2009Feb 2010

First posted11 Sep 2009 (estimated)
Study startOct 2009
Primary completionFeb 2010
Study completionFeb 2010

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Alzheimer's DiseaseStudies of the same condition, open and under way.
More trials run by PfizerThe sponsor's other registered studies.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 1
Allocation: Randomised
Intervention model: Crossover
Masking: Double blind
Who is masked: Participant, Investigator
Enrolment: 36 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT00975481
Sponsor's protocol ID: B1451037
Status last verified: Feb 2013
First submitted: 10 Sep 2009
Last updated: 2 Apr 2013
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

Official record

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Study at a glance

From the registry record, last updated by the sponsor on 2 Apr 2013. Recruitment status is as the sponsor reported it: confirm with the study team.

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
ClinicalTrials.gov ID: NCT00975481
Acronym / sponsor ID: B1451037
Conditions: Alzheimer's Disease, Huntington's Disease
Keywords: oral single-dose 6-way crossover recreational drug users abuse potential pharmacodynamics safety
Phase: Phase 1
Study type: Interventional
Recruitment status: Completed
Enrolment: 36 participants (actual)
Lead sponsor: PfizerIndustry (pharma, biotech, devices)
Collaborators: Medivation, Inc.
Study start: Oct 2009
Primary completion: Feb 2010 (actual)
Study completion: Feb 2010 (actual)
First posted: 11 Sep 2009 (estimated)
Results: Posted 2 Apr 2013

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Dimebon will not exhibit abuse potential when compared to placebo or a positive control (alprazolam).

Detailed description

The main purpose for this study is to determine whether dimebon exhibits abuse potential.

Study design

Allocation: Randomised
Intervention model: Crossover
Masking: Double blind (participant, investigator)
Number of arms: 6

Arm	Type	Receives
dimebon 20 mg	Experimental	Drug: dimebon
dimebon 40 mg	Experimental	Drug: dimebon
dimebon 60 mg	Experimental	Drug: dimebon
placebo	Placebo comparator	Drug: placebo
alprazolam 1 mg	Active comparator	Drug: alprazolam
alprazolam 3 mg	Active comparator	Drug: alprazolam

Who may qualify

Ages: 18 to 55 years
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult

Key inclusion criteria (2 listed)

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

Key exclusion criteria (4 listed)

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.

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
dimebonOral tablet; 20 mg dimebon, single dose	Drug	dimebon 20 mg
dimebonOral tablet; 40 mg dimebon, single dose	Drug	dimebon 40 mg
dimebonOral tablet; 60 mg dimebon, single dose	Drug	dimebon 60 mg
placeboOral tablet or capsule; placebo, single dose	Drug	placebo
alprazolamOral capsule; 1 mg alprazolam, single dose	Drug	alprazolam 1 mg
alprazolamOral capsule; 3 mg alprazolam, single dose	Drug	alprazolam 3 mg

Primary outcome

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.

Results and safety

Results posted to the registry on 2 Apr 2013, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
PBO, ALP 1mg, DIM 60 mg, ALP 3 mg, DIM 40 mg, DIM 20 mg	6	6
ALP 1 mg, ALP 3 mg, PBO, DIM 20 mg, DIM 60 mg, DIM 40 mg	6	6
ALP 3 mg, DIM 20 mg, ALP 1 mg, DIM 40 mg, PBO, DIM 60 mg	6	6
DIM 20 mg, DIM 40 mg, ALP 3 mg, DIM 60 mg, ALP 1 mg, PBO	6	6
DIM 40 mg, DIM 60 mg, DIM 20 mg, PBO, ALP 3 mg, ALP 1 mg	6	6
DIM 60 mg, PBO, DIM 40 mg, ALP 1mg, DIM 20 mg, ALP 3 mg	6	6

Primary outcome: 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. Mean (Standard Deviation). Unit: mm

Measure	Placebo n = 32	Alprazolam 1 mg n = 33	Alprazolam 3 mg n = 34	Dimebon 20 mg n = 33	Dimebon 40 mg n = 32	Dimebon 60 mg n = 31
Emax	57.8 (10.03)	78.6 (17.53)	82.2 (14.55)	57.2 (11.76)	55.8 (9.41)	58.5 (12.54)
Emin	47.0 (9.38)	45.4 (11.21)	37.4 (17.32)	48.4 (8.89)	49.0 (3.59)	46.5 (10.44)

Placebo vs Alprazolam 1 mg: Mean Difference (Final Values): 20.8096 (95% CI 15.0866 to 26.5327), p <0.0001, Mixed Models Analysis
Placebo vs Alprazolam 3 mg: Mean Difference (Final Values): 24.4625 (95% CI 18.7321 to 30.1929), p <0.0001, Mixed Models Analysis
Placebo vs Dimebon 20 mg: Mean Difference (Final Values): -0.5792 (95% CI -6.3385 to 5.1800), p = 0.8428, Mixed Models Analysis

Population analysed: The pharmacodynamic analysis population included all randomized participants in the treatment phase who received at least 1 dose of study medication and had at least 1 pharmacodynamic parameter in at least 1 treatment period.

Primary outcome: Balance of Effects- Overall Drug Liking VAS: Peak Effect (Maximum Effect [Emax]) and Minimum Effect (Emin)

Time frame: 6, 12, 24 hours post-dose. Mean (Standard Deviation). Unit: mm

Measure	Placebo n = 32	Alprazolam 1 mg n = 33	Alprazolam 3 mg n = 34	Dimebon 20 mg n = 33	Dimebon 40 mg n = 32	Dimebon 60 mg n = 31
Emax	57.8 (14.31)	74.6 (18.99)	78.0 (15.50)	56.5 (11.44)	55.4 (11.29)	58.1 (12.52)
Emin	52.5 (9.13)	64.5 (20.17)	62.6 (18.13)	48.2 (15.96)	52.0 (8.75)	51.1 (8.94)

Placebo vs Alprazolam 1 mg: Mean Difference (Final Values): 16.6388 (95% CI 10.5727 to 22.7049), p <0.0001, Mixed Models Analysis
Placebo vs Alprazolam 3 mg: Mean Difference (Final Values): 19.8432 (95% CI 13.7627 to 25.9238), p <0.0001, Mixed Models Analysis
Placebo vs Dimebon 20 mg: Mean Difference (Final Values): -1.6121 (95% CI -7.7209 to 4.4967), p = 0.6029, Mixed Models Analysis

Population analysed: The pharmacodynamic analysis included all randomized participants in the treatment phase who received at least 1 dose of study medication and had at least 1 pharmacodynamic parameter in at least 1 treatment period.

Primary outcome: Balance of Effects- Take Drug Again VAS: Peak Effect (Maximum Effect [Emax])

Time frame: 6, 12, 24 hours post-dose. Mean (Standard Deviation). Unit: mm

Measure	Placebo n = 32	Alprazolam 1 mg n = 33	Alprazolam 3 mg n = 34	Dimebon 20 mg n = 33	Dimebon 40 mg n = 32	Dimebon 60 mg n = 31
Value	53.9 (22.30)	77.5 (22.26)	83.2 (15.99)	47.6 (28.66)	50.4 (26.23)	52.5 (25.66)

Placebo vs Alprazolam 1 mg: Mean Difference (Final Values): 24.0090 (95% CI 13.7265 to 34.2916), p <0.0001, Mixed Models Analysis
Placebo vs Alprazolam 3 mg: Mean Difference (Final Values): 29.4156 (95% CI 19.1160 to 39.7151), p <0.0001, Mixed Models Analysis
Placebo vs Dimebon 20 mg: Mean Difference (Final Values): -6.3979 (95% CI -16.7479 to 3.9521), p = 0.2239, Mixed Models Analysis

Primary outcome: 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. Mean (Standard Deviation). Unit: mm

Measure	Placebo n = 32	Alprazolam 1 mg n = 33	Alprazolam 3 mg n = 34	Dimebon 20 mg n = 33	Dimebon 40 mg n = 32	Dimebon 60 mg n = 31
Emax	56.2 (7.15)	80.9 (15.93)	81.9 (14.40)	57.9 (13.53)	56.6 (11.21)	57.6 (8.92)
Emin	48.0 (8.83)	46.7 (10.70)	38.6 (15.76)	49.3 (2.79)	48.3 (8.82)	48.9 (3.03)

Placebo vs Alprazolam 1 mg: Mean Difference (Final Values): 24.8779 (95% CI 19.5658 to 30.1899), p <0.0001, Mixed Models Analysis
Placebo vs Alprazolam 3 mg: Mean Difference (Final Values): 25.9857 (95% CI 20.6670 to 31.3043), p <0.0001, Mixed Models Analysis
Placebo vs Dimebon 20 mg: Mean Difference (Final Values): 2.0544 (95% CI -3.2911 to 7.3998), p = 0.4489, Mixed Models Analysis

Adverse events

Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Placebo	0 of 32 (0%)	11 of 32 (34.4%)	Not reported
Alprazolam 1 mg	0 of 33 (0%)	30 of 33 (90.9%)	Not reported
Alprazolam 3 mg	0 of 34 (0%)	34 of 34 (100%)	Not reported
Dimebon 20 mg	0 of 33 (0%)	18 of 33 (54.5%)	Not reported
Dimebon 40 mg	0 of 32 (0%)	20 of 32 (62.5%)	Not reported
Dimebon 60 mg	0 of 31 (0%)	17 of 31 (54.8%)	Not reported

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 2 Apr 2013.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
To obtain contact information for a study center near you, click here.Link provided by the sponsor.

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Pfizer CT.gov Call Center study director

Pfizer

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing dimebon and alprazolam in people with Alzheimer's Disease and Huntington's Disease, run by Pfizer.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 2 Apr 2013. Status can change between updates, so confirm with the study contact before making plans.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 2 Apr 2013). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

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). The study lists 15 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00975481.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Apr 2013.