The US Food and Drug Administration (FDA) has asked companies to stop selling all forms of the heartburn drug Zantac, after an investigation found that potential cancer-causing contaminants can build up in the product over time.

The FDA has asked manufacturers of the prescription and over-the-counter drug to pull all supplies from the market with immediate effect.

Consumers were also warned to stop taking the drug and to dispose of any remaining liquids or tablets following FDA disposal instructions.

The US Food and Drug Administration (FDA) has asked companies to stop selling all forms of the heartburn drug Zantac, after an investigation found that potential cancer-causing contaminants can build up in the product over time.

The FDA has asked manufacturers of the prescription and over-the-counter drug to pull all supplies from the market with immediate effect.

Consumers were also warned to stop taking the drug and to dispose of any remaining liquids or tablets following FDA disposal instructions.

However, since we don’t know how or for how long the product might have been stored, we decided that it should not be available to consumers and patients unless its quality can be assured.”

According to the FDA, levels of the contaminant increased over time and when stored at “higher-than-normal” temperatures.

In September, the FDA advised Zantac users to consider switching drugs after it found low levels of NDMA — a probable carcinogen to humans, that can increase the risk of cancer.

Some pharmacy chains such as Walgreens, Walmart and CVS Pharmacy — as well as manufacturers of Zantac — already suspended selling and making the drug several months ago.

Sanofi, the company that produces the Zantac brand, stopped doing so in October. It said in a statement that “We take this issue seriously and continue to work closely with the F.D.A. to evaluate any potential safety risks associated with Zantac.”