Allergan had planned to stop selling Namenda in 2014 and replace it with a once-daily formulation just before the launch of generic versions of the drug in 2015. Namenda XR generated $450 million in sales in 2017. The drug lost patent protection in February 2018, and sales dipped to $71 million that year. In 2019, Namenda XR has only generated $16 million in sales thus far. The lawsuit also claimed that the chief executive of Forest Laboratories, subsidiary of Allergan and manufacturer of Namenda, entered into an illegal agreement with Mylan, a generic manufacturer, to keep its generic version of the drug off of the market. Later in 2014, an injunction was issued by a federal judge that prevented Allergan from switching patients. That ruling was upheld on appeal. The class-action lawsuit alleges that plaintiffs paid too much for Namenda because the company's actions delayed the release of generic versions of the drug. This isn't the first time Allergan has been accused of the "hard switch" tactic.