WASHINGTON - Government medical advisers will meet in September to scrutinize anemia drugs from Johnson & Johnson and Amgen Inc. that have been linked to potentially fatal side effects.The Food and Drug Administration will ask two panels of experts on Sept. 11 whether Amgen’s Epogen and Aranesp, and Johnson & Johnson’s Procrit are safe when used in patients with anemia caused by kidney failure. The drugs racked up combined sales of $10 billion last year.