Twelve patients with Alzheimer's disease received 0.0, 0.5, 1.0, 1.5,
and 2.0 mg of oral physostigmine every 2 hours for 3-5 days; symptoms after
each dose were assessed with the Alzheimer's Disease Assessment Scale.
Placebo and the dose associated with the least severe symptoms were then
readministered for 3-5 days each. Of the 10 patients who completed the
study, three showed clinically significant improvement on the highest
physostigmine dose in both phases, four more were marginally improved in
both phases, and three had inconsistent responses to physostigmine.
Cortisol measures obtained during a sleep study suggest that patients whose
symptoms improved on physostigmine were those in whom oral physostigmine
enhanced central cholinergic activity.