Conditions: Alzheimer's Disease Dementia
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 4
Healthy volunteers: yes

Brief summary:
This study will evaluate acute symptomatic improvements in cognitive performance in healthy elderly participants with mild-to-moderate Alzheimer's disease. A four-week pilot study will first evaluate the CogState computerized cognitive battery in participants who are not receiving treatment. After completion of the pilot study, participants will be randomized to receive Placebo, Donepezil 5 mg, MK-0249 7.5 mg, and MK-0249 25 mg. After each drug administration the participants will be given the CogState computerized cognitive battery to assess cognitive performance. The primary hypotheses are that cognitive performance in participants with Alzheimer's disease, or in healthy participants, is improved by the administration of a single oral 5 mg dose of Donepezil as compared to placebo.

Detailed description:

Arms:
arm 1: Treatment by single oral dose with Placebo (PBO) in the first crossover period; MK-0249 7.5 mg (MK-7.5) in the second crossover period; Donepezil 5 mg (DON) in the third crossover period; and MK-0249 25 mg (MK-25) in the fourth crossover period. arm 2: Treatment by single oral dose with MK-0249 7.5 mg in the first crossover period; Placebo in the second crossover period; MK-0249 25 mg in the third crossover period; and Donepezil 5 mg in the fourth crossover period. arm 3: Treatment by single oral dose with Donepezil 5 mg in the first crossover period; MK-0249 25 mg in the second crossover period; Placebo in the third crossover period; and MK-0249 7.5 mg in the fourth crossover period. arm 4: Treatment by single oral dose with MK-0249 25 mg in the first crossover period; Donepezil 5 mg in the second crossover period; MK-0249 7.5 mg in the third crossover period; and Placebo in the fourth crossover period. arm 5: Treatment by single oral dose with Placebo in the first crossover period; MK-0249 25 mg in the second crossover period; MK-0249 7.5 mg in the third crossover period; and Donepezil 5 mg in the fourth crossover period. arm 6: Treatment by single oral dose with MK-0249 7.5 mg in the first crossover period; Donepezil 5 mg in the second crossover period; Placebo in the third crossover period; and MK-0249 25 mg in the fourth crossover period. arm 7: Treatment by single oral dose with Donepezil 5 mg in the first crossover period; MK-0249 7.5 mg in the second crossover period; MK-0249 25 mg in the third crossover period; and Placebo in the fourth crossover period. arm 8: Treatment by single oral dose with MK-0249 25 mg in the first crossover period; Placebo in the second crossover period; Donepezil 5 mg in the third crossover period; and MK-0249 7.5 mg in the fourth crossover period. arm 9: Treatment by single oral dose with Placebo in the first crossover period; Donepezil 5 mg in the second crossover period; MK-0249 25 mg in the third crossover period; and MK-0249 7.5 mg in the fourth crossover period. arm 10: Treatment by single oral dose with MK-0249 7.5 mg in the first crossover period; MK-0249 25 mg in the second crossover period; Donepezil 5 mg in the third crossover period; and Placebo in the fourth crossover period. arm 11: Treatment by single oral dose with Donepezil 5 mg in the first crossover period; Placebo in the second crossover period; MK-0249 7.5 mg in the third crossover period; and MK-0249 25 mg in the fourth crossover period. arm 12: Treatment by single oral dose with MK-0249 25 mg in the first crossover period; MK-0249 7.5 mg in the second crossover period; Placebo in the third crossover period; and Donepezil 5 mg in the fourth crossover period.

Interventions: intervention 1: MK-0249 7.5 mg intervention 2: MK-0249 25 mg intervention 3: Donepezil 5mg intervention 4: Placebo to MK-0249 intervention 5: Placebo to Donepezil
Intervention descriptions: intervention 1: 4 tablets (1 x 0.5 mg + 2 x 1 mg + 1 x 5 mg) totaling 7.5 mg, single oral dose during each crossover period intervention 2: 5 x 5 mg tablets totaling 25 mg, single oral dose during each crossover period intervention 3: One 5 mg tablet, single oral dose during each crossover period intervention 4: Five tablets, single oral dose during each crossover period intervention 5: One over-encapsulated capsule, single oral dose during each crossover period

Protocol document: