Galanthamine versus donepezil in the treatment of Alzheimer's disease

To use comparative studies on the utilisation of the acetylcholinesterase inhibitors (AchE), galanthamine and donepezil, to evaluate the effectiveness and tolerance of the two drugs in the treatment of the symptoms of Alzheimer's disease (AD). A search was conducted on Medline for papers dealing with galanthamine and donepezil that had been published up to February 2007. Six comparative studies involving galanthamine and donepezil were found, although there are other studies that compare them together with other AchE inhibitors. Both drugs are moderately effective in the treatment of AD. Nevertheless, whereas in the case of donepezil there seems to be a positive relation between the maximum dosage and response, for galanthamine doses above 24 mg/day do not seem to offer any improvement. In general, treatment was well tolerated in all the studies. Maximum recommended doses (24 mg/day for galanthamine versus 10 mg/day for donepezil) were more often reached in patients treated with donepezil. The five most common side effects were, in order of frequency of presentation: nausea, agitation, vomiting, headache and fainting. In the long term, the most frequent side effects from anticholinesterases are, generally speaking, muscle cramps, tremors, nightmares, nausea, vomiting, fatigue, vertigo and loss of weight. The studies analysed show limitations in the design, duration, sample sizes and the titration schemes of the drugs.