Monthly mass tort ad spending targeting the anti-nausea drug Zofran and its manufacturer GlaxoSmithKline, increased by over 8,000% in February -- the largest spike for any drug or medical device featured in mass tort ads in over 6 months.

Twenty-five law firms sponsored over 1,300 ads featuring Zofran last month at a combined cost of approximately $2 million. By comparison, under $25,000 was spent to air fewer than 200 ads in January.

The advertising blitz follows the filing of lawsuits against GlaxoSmithKline alleging that the drug caused birth defects in children born to women who took Zofran while pregnant.

Over 95% of the spending on Zofran mass tort ads was devoted to spots for broadcast on national networks -- reflecting the expected national scope of the litigation.

More Zofran mass tort ads were broadcast on local broadcast networks in Boston, Philadelphia, and Bakersfield than any other local media market.

In 2012, the US Department of Justice announced that GlaxoSmithKline would pay more than $1 billion to settle claims that it illegally marketed medications for off-label, unapproved uses including allegations that the company promoted Zofran, approved only for post-operative nausea, for treatment for morning sickness in pregnant women.