Walgreens is the latest retailer to suspend sales of Sanofi's heartburn medication Zantac and other generic ranitidine products while the U.S. Food and Drug Administration reviews their safety.
"We are removing Zantac and ranitidine products from our shelves while the FDA continues its review of the products," the company said in a written statement.
CVS Health announced Saturday it was discontinuing sales of the medication as well as its own generic ranitidine products.
The news comes after Valisure, an online pharmacy company, alerted the FDA earlier this month that Zantac includes an impurity that could cause cancer.
Health officials said they have been investigating the carcinogen, called N-nitrosodimethylamine or NDMA, in blood pressure and heart failure medicines since last year.
"The FDA is not calling for individuals to stop taking ranitidine at this time; however, patients taking prescription ranitidine who wish to discontinue use should talk to their health care professional about other treatment options," the FDA said in the statement when it announced the probe.
Earlier this month, the FDA said that although NDMA may cause harm in large amounts, the levels it is finding from preliminary tests aren't much higher than what's found in common foods. The FDA is evaluating whether low levels pose a risk to patients.
"We are working closely with the FDA and are conducting our own robust investigations to ensure we continue to meet the highest quality safety and quality standards," Sanofi told CNBC in a written statement.
Sanofi said it remains "committed to being transparent with our patients and consumers and will share an update when one is available."
Several blood pressure drugs have been recalled after NDMA was found in them earlier this year. Torrent Pharmaceuticals and Camber Pharmaceutical said they would recall products with losartan, which is used to treat high blood pressure, and Teva Pharmaceuticals said it would expand a recall of its heart medication after the substance was found in it.