Pfizer was expected to introduce a deeply discounted generic version of its brand name antidepressant Zoloft through its Greenstone division after the drug lost patent protection on June 30.“We see a big opportunity with our big medicines coming off patent,” Pfizer CEO Hank McKinnell said The Wall Street Journal. “The generic companies hate it, of course. They don’t want the competition.”According to IMS Health figures, Greenstone had sales of $722 million in 2005, making it the seventh-largest generics company in the US. Pfizer does not disclose Greenstone sales. Greenstone’s top products include generic versions of blood pressure treatment Accupril, epilepsy medication Neurontin and antibiotic Zithromax, all Pfizer brands which have gone generic. McKinnell told The Journal there are still plenty of sales to go around, regardless of whether an authorized generic is part of the mix.“I don’t think we’re going to do too much damage to the generics companies,” he said. “We’re not going to put them out of business.”