Don't take your alzheimer's drug at bedtime

Main Category: Sleep / Sleep Disorders / Insomnia
Article Date: 10 Feb 2004 - 0:00 PDT


Millions of Alzheimer's patients who take memory-boosting drugs may impair their ability to remember by taking the medicine at bedtime, according to a study published recently in the Proceedings of the National Academy of Sciences (USA).

The study also raised the possibility that 'brain foods' and memory-boosting nutrient supplements -- popular among older people without Alzheimer's disease -- may backfire and impair memory if consumed before sleep.

The brain uses choline to make acetylcholine, a messenger molecule important in memory. Individuals with Alzheimer's disease have ab-normally low levels of acetylcholine, and the widely used Alzheimer's drugs -- Aricept, Exelon and Reminyl -- work by raising them. Memantine, a new Alzheimer's drug, works in a different way.

Doctors usually have patients take acetylcholine drugs at bedtime because doing so reduces side effects, said explained Dr. Steven T. DeKosky, professor and chairman of neurology at the University of Pittsburgh.

In the new study, Dr. Steffen Gais of the University of Lubeck in Germany tested memory in 29 men given bedtime doses of a drug that keeps acetylcholine levels high. The men were young, aged 18-35, and healthy.

The drug seriously impaired their memories. Men given the drug were less able to remember words learned the previous day than men who took none.

'It would be of great interest to assess the possibility that aged individuals or patients with Alzheimer's disease -- both of which have impaired sleep and impaired memory -- may be altered by high choline levels via diet prior to bedtime,' said Dr. Lisa Teather of Canada's Laurier University, who was not involved in the study.

Dr. Ann Power, a memory expert at the University of California-Irvine, termed the results 'compelling.' The discovery may seem like a contradiction, she explained in an interview, but it makes sense.

In Alzheimer's patients, brain cells that make acetylcholine have been damaged, resulting in lower levels of the chemical. During the day, drugs like Aricept keep acetylcholine levels high and boost memory.

The Gais' study, however, revealed that the brain needs a temporary drop in acetylcholine during sleep so that it can upload data from a temporary storage depot to another region that holds more permanent memories.

'This study teaches us that although patients may need increased acetylcholine during waking, keeping it constantly elevated may block a certain component of memory consolidation that requires a temporary drop in acetylcholine,' Power said.

Both she and Gais said physicians should consider advising Alzheimer's patients to take medicine during the day, rather than at bedtime.

DeKosky praised the study as 'very carefully done,' but he said more research is needed to see if the results apply to people with Alzheimer's. DeKosky directs Pitt's Alzheimer's Disease Research Center, one of 30 established nationwide by the federal government to translate research advances into improved care for Alzheimer's patients.

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