The company said in a statement to investors, external that the settlements “remove significant financial uncertainty, risk and distraction associated with protracted litigation.”
Zantac was first approved for sale in the US in 1983.
Within five years it was the world’s best-selling drug, with annual sales topping $1bn.
In 2020, US regulators pulled Zantac off shelves due to fears that a key ingredient, ranitidine, could turn into a substance that may cause cancer when exposed to heat.
That move led to tens of thousands of lawsuits against the drug’s manufacturers.
The previous year, UK doctors were told to stop prescribing four types of Zantac as a “precautionary measure”.
It followed concerns in several countries that the products may contain the impurity.
As well as being sold by GSK, the drug has also been marketed by other major pharmaceutical firms Pfizer, Sanofi and Boehringer Ingelheim.
Pfizer and Sanofi have both agreed to settle cases.
Boehringer Ingelheim is the exception. It has not announced any major settlements.
A drug under the name of Zantac 360, which contains no ranidine, is still being currently sold.