Just days before its blockbuster merger announcement with Actavis, drug maker Forest Laboratories Inc. filed a lawsuit in federal district court in Delaware accusing several generic pharmaceutical manufacturers of infringing patents related to its exclusive treatment for Alzheimer’s disease.

The complaint, filed by Quinn Emanuel Urquhart & Sullivan on Feb. 14, is part of an effort by Forest Labs to protect its branded Alzheimer’s drug, Namenda. The suit targets Canada’s Apotex Inc.; India’s Cadila Healthcare; and New Jersey’s Par Pharamceutical Inc., among others.

It is unclear what impact, if any, this week’s announcement will have on the litigation. On Tuesday, pharmaceutical giant Actavis said it would buy Forest Labs for an estimated $25 billion in cash and stock. Reuters reported that Actavis had previously sought to sell its own generic version of Namenda.