Nicotine has been related to recovery of memory in humans and animal models and some observational studies have been compatible with a protective effect of nicotine inhalation against Alzheimer's disease. At present, there is great controversy over this possible effect of tobacco use, and evidence is inconclusive. This review found no evidence on which to recommend nicotine for Alzheimer's disease.
This review is not able to provide any evidence that nicotine is or is not a useful treatment for Alzheimer´s disease.
Nicotine is a cholinergic agonist that also has a presynaptic effect in releasing acetylcholine. It has been shown to reverse spatial memory deficits produced in rats by lesions in the medial septal nucleus of their brains, and, in aged monkeys, nicotine administration improves memory and alertness to visual stimuli. Observational studies have suggested a protective effect of smoking against Alzheimer's disease, but recent studies have called this into question. Smoking is a risk factor for stroke and so, possibly, for vascular dementia. Because nicotine has adverse effects, it is important to conduct a systematic review to assess its clinical efficacy and safety for people with Alzheimer's disease.
To evaluate the efficacy and safety of nicotine, administered in any way or form, for people with Alzheimer's disease.
ALOIS, the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (CDCIG), The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS and other sources were searched on 25 March 2010.
The latest search performed in March 2010 retrieved four new studies for consideration; none of these met the inclusion criteria for the review.
All unconfounded, double-blind, randomized trials in which treatment with nicotine patches, or administration of nicotine intravenously, or in any other way or form, was administered for more than a day and compared with placebo for people with Alzheimer's disease.
The one included trial did not present results suitable for inclusion in the review.
There were no results available from the one included study.