Dementia
Conditions
Keywords
dementia, cognitive impairment, neurodegeneration, Alzheimer's, acetylcholine, AchE
Brief summary
The drug, scopolamine, can result in short-term impairments of cognitive function, attention, and memory that resemble those seen in aging and Alzheimer's disease. This study tested the capability of both individual and combined doses of MK-3134 and the current standard treatment: donepezil (Aricept), to reverse such impairments, following a single dose of scopolamine. Participants were evaluated after each of 5 different treatment periods (in a cross-over, double-dummy design): A: placebo to match both donepezil (oral \[PO\]) and MK-3134 (PO) followed by placebo scopolamine (subcutaneous \[SQ\]); B: placebo to match both donepezil (PO) and MK-3134 (PO), followed by scopolamine SQ; C: MK-3134 (PO) followed by scopolamine SQ; D: donepezil (PO) followed by scopolamine SQ; E: MK-3134 (PO) and donepezil (PO) followed by scopolamine SQ. The doses of MK3134, donepezil, and scopolamine were the same over all treatment arms in which the specified drug was administered. There were 8 total visits for each treatment period, including 5 Treatment Visits requiring 14-day intervals between visits for study-drug washout. Participants were assessed for cognitive function before and after each treatment period during the Treatment Visits.
Interventions
DRUGA: Placebo to match Donepezil and MK-3134 + Placebo to match Scopolamine
Single doses of placebo to match both donepezil and MK-3134 PO, plus a single dose of placebo to match scopolamine SQ.
DRUGB: Placebo to match Donepezil and MK-3134 + Scopolamine 0.5 mg
Single doses of placebo to match both donepezil and MK-3134 PO, plus a single dose of scopolamine 0.5 mg SQ.
DRUGC: MK-3134 25 mg + Scopolamine 0.5 mg
A single dose of MK-3134 PO 25 mg, plus a single dose of scopolamine SQ 0.5 mg.
DRUGD: Donepezil 10 mg + Scopolamine 0.5 mg
A single dose of donepezil 10 mg PO, plus a single dose of scopolamine 0.5 mg SQ.
DRUGE: Combo: Donepezil 10 mg + MK-3134 25 mg + Scopolamine 0.5 mg
A combination of single doses of all active drugs: donepezil 10 mg and MK-3134 25 mg PO, plus scopolamine, SQ.
Sponsors
Merck Sharp & Dohme LLC
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
MALE
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
Participants were eligible for inclusion in the study who were: * Male between 18 and 40 years of age. * Non-smokers, in good health (as defined in protocol), and were willing to follow study-related procedures. Participants were not eligible for inclusion in the study if they: * Had a history of illness that, in the opinion of the study investigator or as specified in protocol, might confound the results of the study or posed an potential, additional risk to the participant if they were to participate in the study. * Were taking any medication (prescription, nonprescription, vitamin supplements or herbal, illicit or legitimate) except for acetaminophen. * Had a history of any significant head injury/trauma.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| CogState Early Phase Battery, Groton Maze Learning Test (GMLT) as measured by the number of errors on the GMLT over time (area under the GMLT-time curve) over hours 1-12. | 1, 2, 3, 4, 6, 8, and 12 hours relative to administration of SQ scopolamine or SQ placebo | Participants learned a hidden pathway through a maze (10 x 10 grid of tiles on a computer touch screen) using step-by-step guess, with trial and error feedback after each step. Once the pathway was learned, participants repeated the same pathway four more times. The number of pathway errors was used to indicate the level of cognitive function. |
Outcome results
None listed