Washington, July 28: A preliminary study by British American researchers has hinted that drugs given to Parkinson's patients and the elderly may hasten the onset of Alzheimer's disease. According to a report in 'Nature', Antimuscarinic drugs prescribed to 5-10 per cent of Parkinson's patients to help control tremors, bladder problems and depression block some of the actions of a brain chemical called acetylcholine. Parkinson's patients who had taken the medicines for more than two years had roughly twice the usual level of protein usual level of protein clumps and tangles compared to those not on drugs, found Elaine Perry of Newcastle General Hospital, UK, according to a report in The nature. Clumps and tangles are characteristic of Alzheimer's patients.



Perry's team examined 120 records from a British brain bank, obtained from patients over 70 years of age. The team says that doctors should not jump to switch therapies. None of the patients examined had actually shown symptoms of Alzheimer's.


Allan Levey, who studies nervous-system disease at Emory School of Medicine in Atlanta, Georgia, said the results of the study were a cause for concern. Millions of people take drugs such as tricyclic antidepressants, antihypertensives and antihistamines that block acetylcholine indirectly, even though these medicines target other molecules.

"It's hard to find elderly people who aren't on them," Levey says. New studies should monitor whether these patients are at greater risk of Alzheimer's, he suggests.


Animal studies suggest that acetylcholine stimulants stall plaque growth; human trials are under way to explore whether the drugs protect people from Alzheimer's.
Bureau Report