Looks like Barr Labs (NYSE:BRL) will be back in court dealing with a patent lawsuit again. The company's all too familiar with such a setting -- but it's usually sitting on the defendant's side of the courtroom, not the plaintiff's.

On Friday, Barr announced that it was suing both Watson Pharmaceuticals (NYSE:WPI) and Novartis' (NYSE:NVS) generic subsidiary Sandoz for patent infringement regarding Barr's SEASONALE extended-cycle birth control pill.

Watson has been selling a competing generic version of the drug for more than a year now, but the lawsuit was probably spurred on by Novartis informing Barr last month that it had filed a marketing application to sell the drug. According to an FDA study of generic drug prices, the introduction of a second generic competitor reduces the generic price to nearly half as much as the brand-name product, putting greater pricing pressure on the branded version.

If Barr wins the case, it could get royalties on previous sales of Watson's product. That makes its benefit from suing more than just protecting its patent, which it claims extends until 2017.

Unfortunately, unless you have in-depth knowledge of the proceedings, it's almost impossible to guess who will win a patent lawsuit. As an investor, your best hope is to inspect the courtroom track record of the drug companies in which you invest. Look for companies that have been able to defend their branded patents and, in the case of generic-drug makers, how well they're able to break patents of branded products.

Barr has a mixed record in the courtroom in 2007; it won one appeal, settled another case, withdrew two lawsuits, and lost one against recently acquired PLIVA. Only time will show how well Barr does with regard to SEASONALE.

More Foolishness about drugmakers' lawsuits:

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Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. The Fool has a disclosure policy.