CVS has halted sales of popular heartburn treatment Zantac and the store generic version after warnings by U.S. health regulators.

CVS is the latest retailer to pull the heartburn tablets from store shelves. Earlier this month, the U.S. Food and Drug Administration warned consumers about a potentially dangerous contaminant in prescription and over-the-counter versions of Zantac.

In its announcement this weekend, CVS said customers who bought Zantac products can return them for a refund. The retailer will continue to sell other heartburn medications such as Pepcid.

Some manufacturers of the drug have stopped distribution. Health officials say concerned patients should consult their doctor.