A drug that was once used as an antihistamine by people with allergies in Russia offers new hope for Alzheimer's patients, a study published today suggests. The drug, dimebon, has so far been trialled on only 183 patients, but it led to significant improvement in the understanding and behaviour of patients with mild to moderate Alzheimer's disease, according to the research published in the Lancet medical journal. Treatments for Alzheimer's are badly needed. Those that exist are controversial; arguments rage over whether or not Aricept and similar drugs work well enough to be worth their high cost. The 183 patients from 11 different sites were randomly divided into two groups and given either dimebon three times a day or a placebo.