Zantac Cancer Lawsuit Medical Record Review The Zantac Cancer lawsuit  is a massive legal action involving tens of thousands of people who claim that taking the popular heartburn medication Zantac (and its generic form, ranitidine) caused them to develop cancer. Zantac (ranitidine) was once one of the most widely prescribed and over-the-counter heartburn medications in the world. In 2019–2020, the FDA requested its removal from the market after independent laboratory testing