Israel-based generic drugmaker Teva Pharmaceutical yesterday began the sale of its generic version of Pfizer’s Zoloft (sertraline) in the US. As the first company to file an abbreviated new drug application for this product, Teva has been awarded a 180-day period of marketing exclusivity. Zoloft is indicated for the treatment of major depressive disorder. Annual US sales of Zoloft were approximately $3.1 billion in sales for the twelve months ending June 2006, based on IMS data.Wall Street analysts estimate Pfizer will lose nearly $2 billion in sales as a result of Zoloft going off patent, although this won’t necessarily translate into more sales for its brand-name competitors. “(The branded antidepressants) are not interchangeable,” Barbara Ryan, analyst for Deutsche Bank North America told “(This) is unlikely to have much of an effect on the category.”Pfizer was expected to also offer a deeply discounted generic version Zoloft through its Greenstone generics division.