SIOUX FALLS, S.D. — Lewis Drug stores has joined the growing list of drug chains removing all forms of Zantac from store shelves.

This includes brand name and generic products, including their private label Premier Value ranitidine products. Some ranitidine products were found to contain low levels of an impurity called N-nitrosodimethylamine (NDMA). “Not all versions of ranitidine have been found to have this impurity and therefore not all have been recalled. The Food and Drug Administration (FDA) has not called for people to stop taking the medication that they may have at home or that remains on the market. But the FDA has advised patients who wish to stop taking ranitidine to talk to their doctors or pharmacists about alternatives for the anti-heartburn medication that is commonly used as a prescription and over-the-counter to treat acid reflux or ulcers,” the company said in a statement.

Exposure to low levels of NMDA does not pose an acute risk to patients. The chemical is classified as a probable carcinogen and is an environmental contaminant that can also be found in foods.

“Lewis Drug takes consumer safety very seriously. So we are exercising an abundance of caution in suspending sales of ranitidine products,” the company added.