Dementia
Conditions
Brief summary
This study will evaluate functional magnetic resonance imaging (fMRI) and methods for measuring drug induced changes in cerebral blood flow as biomarkers for attention-improving drugs.
Interventions
DRUGMK3134
Single dose 25 mg (5 x 5 mg) MK3134 capsules in one of the four treatment periods.
DRUGComparator: Placebo
Placebo capsules only in one of the four treatment periods.
DRUGDonepezil
Single dose 5 mg donepezil capsules in two of the four treatment periods.
Sponsors
Merck Sharp & Dohme LLC
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
DIAGNOSTIC
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
MALE
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Subject is a nonsmoker * Subject is in generally good health * Subject has normal (or corrected to normal) vision and hearing * Subject is right-handed
Exclusion criteria
* Subject has a history of any illness that would make participation unsafe or would make the study results difficult to interpret * Subject has a history of stroke, seizures, or major neurological disorders * Subject has a history of cancer * Subject has permanent cosmetic or metallic implants that would interfere with measurements * Subject has a history of sleep apnea * Subject has a history of head injury/trauma
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Part I: Difference in number of voxels showing a positive response after treatment with donepezil and placebo | 3.5 to 4.5 hours after study drug administration |
| Part I: Difference in number of voxels activated for both faces and scenes after treatment with donepezil and placebo | 3.5 to 4.5 hours after study drug administration |
| Part II: Number of voxels showing a positive response after varying doses of MK3134 compared to placebo | 3.5 to 4.5 hours after study drug administration |
| Part II: Number of voxels activated for both faces and scenes after varying doses of MK3134 compared to placebo | 3.5 to 4.5 hours after study drug administration |
Secondary
| Measure | Time frame |
|---|---|
| Part I: Difference in Pulsatility index after treatment with donepezil and placebo | 5 hours after study drug administration |
| Part II: Change in Pulsatility index after treatment with placebo and varying doses of MK3134 | 5 hours after study drug administration |
| Part I: Test-retest reproducibility of the BOLD fMRI and cerebral blood flow measurements in donepezil treated subjects | 1 to 5 weeks |
| Part I: Difference in arterial transit time as measured by arterial spin labeling after treatment with donepezil and placebo | 3.5 to 4.5 hours after study drug administration |
| Part II: Change in arterial transit time after treatment with placebo and varying doses of MK3134 | 3.5 to 4.5 hours after study drug administration |
Outcome results
None listed