Two of the nation's major pharmacy chains have announced they are discontinuing the sale of the heartburn medication Zantac (and their respective generic versions of the drug) over over concerns about long-term health effects.

ABC News reports CVS and Walgreens have pulled the over-the-counter medication from their shelves, citing a  a Food and Drug Administration alert earlier this month that the medicine contained "a possible carcinogen."

"Zantac brand products and CVS brand ranitidine products have not been recalled, and the FDA is not recommending that patients stop taking ranitidine at this time," CVS said in a statement. CVS says Customers who previously purchased Zantac, under its brand name generic name of ranitidine can return it to the stores for a refund.

A Walgreen spokesman told ABC it would be "removing Zantac and ranitidine products from our shelves while the FDA continues its review of the products."

Results from FDA lab tests showed some heartburn pills contained a "probable carcinogen" called N-nitrosodimethylamine (NDMA) in small amounts. The ABC reports says NDMA may increase cancer risk "when taken in high doses over a long period of time."

If you have any questions you should contact your pharmacist.

[Source: ABC News online]