The drug Zofran (Ondansetron) was manufactured to help cancer patients to treat nausea that usually follows chemotherapy treatments. The FDA's approval of Zofran was limited to only this use. However, manufacturer GlaxoSmithKline took the liberty of marketing the drug to pregnant women to treat morning sickness. Unfortunately, not only did the FDA not approve the drug for this use, but studies soon found that use of the drug to treat morning sickness was linked to birth defects.
After pleading guilty to federal charges of fraud and illegal promotion, and settling the matter for $3 billion, the manufacturer now faces various others pending lawsuits as a result of the injuries stemming from Zofran's unapproved use.