An N-of-1 randomized controlled trial ('N-of-1 trial') of donepezil in the treatment of non-progressive amnestic syndrome.
BACKGROUND
a professional man sustained a residual, persisting, isolated impairment of short-term memory secondary to severe carbon monoxide poisoning. Informal, open trial of the cholinesterase inhibitor donepezil resulted in uncertain benefit.


METHODS
an N-of-1 randomized, double-blind controlled trial of donepezil against placebo. Placebo-induced headache permitted evaluation of donepezil at only the 5 mg dose.


RESULTS
there was no improvement in short-term memory.


CONCLUSIONS
the trial excluded significant benefit of donepezil 5 mg in this patient, preventing long-term unnecessary prescription. Beneficial effects in other similar patients or at higher dosage cannot be excluded.
Price
James D
JD
Division of Clinical Geratology, Nuffield Department of Clinical Medicine, University of Oxford, Radcliffe Infirmary, Oxford OX2 6HE, UK. james.price@geratology.oxford.ac.uk
Grimley Evans
John
J
D002800:Cholinesterase Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D000077265:Donepezil; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D006801:Humans; D007189:Indans / Q000009:adverse effects / Q000627:therapeutic use*; D008570:Memory, Short-Term; D010880:Piperidines / Q000009:adverse effects / Q000627:therapeutic use*
D002800:Cholinesterase Inhibitors; D007189:Indans; D010880:Piperidines; D000077265:Donepezil