Abbott Laboratories ($ABT) set aside $1.5 billion for a potential off-label marketing settlement with the U.S. Justice Department. If the settlement closes at $1.5 billion, it would rank as the second-largest off-label settlement in history, outranked only by Pfizer's $2.3 billion deal.

The potential legal settlement would resolve a longstanding investigation into Abbott's Depakote promotions. Whistleblower lawsuits allege that Abbott pushed the epilepsy drug, which is also approved for bipolar mania and migraine prevention, for a variety of unapproved uses. The company boasted that Depakote could treat autism, sexual compulsions, agitated and aggressive dementia patients, along with other conditions. The unapproved uses were promoted in a variety of U.S. healthcare settings, including long-term care and assisted-living facilities.

Off-label marketing settlements have become commonplace in the drug industry. Johnson & Johnson recently agreed to pay $81 million to settle a Risperdal marketing probe. In 2008, 2009, and 2010, Pfizer agreed to a $2.3 billion settlement of claims that it promoted Bextra and several other drugs for unapproved uses. Eli Lilly's agreed to a $1.4 billion Zyprexa settlement, Allergan agreed to a $600 million Botox settlement, and AstraZeneca's agreed to a $520 million Seroquel settlement.