Attempts by Actavis to switch patients to Namenda XR—a newer formulation of its Alzheimer’s disease drug Namenda IR—will come “at a substantial cost to consumers and taxpayers,” the government said.

The Department of Health and Human Services released documents on May 6 that look at the potential costs of discontinuing Namenda IR.

“The removal of Namenda IR from the market prior to the release of any generic counterpart would result in higher market prices and some patients may also suffer from discontinued therapy due to a disruption in their treatments regimens,” the report added.

The HHS outlined three scenarios and found that if Namenda IR is withdrawn from the market completely, it would increase spending for Medicare and its beneficiaries by $6 billion over the next ten years.

Robert Sweet, a federal judge for the US District Court for the Southern District of New York, had ordered the drugmaker to keep Namenda IR on the market in December after New York Attorney General Eric Schneiderman filed an antitrust lawsuit against the company, alleging it intentionally planned to discontinue the drug to suppress generic competition.