The U.S. Food and Drug Administration has approved Teva Pharmaceutical Industries Ltd. to sell a generic version of blockbuster Alzheimer''s drug Aricept, according to the Associated Press. Aricept is jointly marketed by New York-based Pfizer Inc. and Japanese drugmaker Eisai Co. Ltd. Jerusalem-based Teva said that it has already begun shipping the product, in 5 milligram and 10 milligram tablets. Sales of brand-name and generic Aricept total about $2.3 billion in the United States. Pfizer reported $417 million in revenue from Aricept in 2010, but noted it lost exclusivity for the drug in November. Aricept had been the market leader among drugs that alleviate symptoms of Alzheimer''s disease, such as memory problems, confusion and aggression.