NORFOLK, Va. (AP) -- Pfizer Inc. has filed a lawsuit against a rival drug maker that plans to introduce a generic version of Viagra.
Pfizer alleges in its lawsuit in U.S. District Court in Norfolk that Teva Pharmaceuticals plans to roll out its version of sildenafil citrate in 2012, which Pfizer says would violate one of its patents.
If Teva succeeds, it would cut into Pfizer's sales of its erectile-dysfunction drug, worth more than $1 billion annually.
New York-based Pfizer has asked the court to bar Teva from making or distributing a generic version of Viagra before 2019. Teva is based in Israel.
Teva spokeswoman Denise Bradley declined to comment on the lawsuit. A Pfizer spokesman didn't comment Tuesday.
