Fears that US juries could hold drug companies responsible for cancers allegedly caused by contaminants in a once-popular antacid led to one of the biggest sell-offs in healthcare stocks in decades, as investors pulled $US40 billion ($56 billion) from Sanofi, GSK and its consumer health spin-off Haleon in the past few days.

The recalled heartburn drug Zantac is the latest to face a wave of US product-liability lawsuits that could expose companies to billions of dollars in damages from jury trials.

Bloomberg