Treatment of Alzheimer's disease with clioquinol

As heavy metal ions may be implicated in the formation of senile plaques in Alzheimer-afflicted brains, treatment with clioquinol was tested in 20 pat ients with Alzheimer's disease. Clioquinol is a chelator that crosses the b lood-brain barrier and has greater affinity for zinc and copper ions than f or calcium and magnesium ions. Treatment was given for 21 days at doses of 20 mg/day to 10 patients and 80 mg/day to another 10 patients. The study wa s blind to the dosages but included no controls. Cerebrospinal fluid (CSF) investigations revealed a significant increase at day 7 and a decrease at d ay 21 in Tau protein and growth-associated protein (GAP43). These proteins are increased in Alzheimer's disease and considered as rather stable marker s. The initial increase may indicate a temporary cytotoxicity to the brain and/or an increased release into the CSF from stores in the tissue, possibl y from senile plaques where the proteins are accumulated. The levels of CSF -Tau protein correlated positively and significantly with the serum levels of copper and also with the serum copper/zinc ratio. Clinical ratings showe d slight improvement after 3 weeks treatment with clioquinol in this open s tudy. Copyright (C) 2001 S. Karger AG, Basel.