Oct 2 (Reuters) - The U.S. Food and Drug Administration said on Wednesday it found "unacceptable levels" of a cancer-causing impurity in limited testing using low-heat method of samples of heartburn medicines such as Zantac containing the ingredient ranitidine.
However, the agency said its testing method found much lower levels of the impurity, N-nitrosodimethylamine, than a higher temperature method used by third-party laboratories. The FDA recommends the low-heat testing method for the drugs.
Earlier in the day, Walmart Inc joined pharmacy chains CVS Health Corp, Walgreens Boots Alliance Inc and Rite Aid Corp in suspending sale of the medicines. (Reporting by Saumya Sibi Joseph in Bengaluru; Editing by Maju Samuel)