Teva Pharmaceuticals is suing several other generic drug companies that seek to challenge its position as the lone maker of non-branded Zoloft.Companies named in the suits include Novartis AG’s Sandoz and Lupin Laboratories.Zoloft (sertraline), an antidepressant marketed by Pfizer, lost patent protection in June. Teva began selling a generic version in September and has sole rights to do so until Feb. 6, the expiration date for its 180-day exclusivity period on producing sertraline.The FDA gave its tentative nod for several others to receive approval to make generic copies on that date, including Sandoz and Lupin. The Teva suits, filed in New Jersey and Delaware, target would-be sellers of generic Zoloft, plus companies that make the active ingredient, according to Bloomberg.Other companies Teva is suing are Apotex, Cipla, Cadila Healthcare’s Zydus-Cadila Healthcare, Merck KGaA’s Genpharm, and Watson Pharmaceuticals’s Andrx, as well as manufacturers Invagen Pharmaceuticals, Hetero Drugs and Torrent Pharmaceuticals, according to court records cited by Bloomberg.