Merrell Dow

American pharmaceutical company at Cincinnati in Ohio, formed in 1959 when Dow Chemical bought the William S. Merrell company and run as Merrell Dow Pharmaceuticals until it merged with Marion Laboratories in 1989. Made and sold prescription medicines including the antihistamine terfenadine and cardiovascular and central nervous system products, and ran research laboratories in Cincinnati and Strasbourg before its business passed through Hoechst Marion Roussel and Aventis to Sanofi.