The maker of the popular heartburn medication Zantac said it has stopped distributing the drug worldwide pending investigations.
The Sandoz division of the Swiss pharmaceutical corporation Novartis said it made a "precautionary distribution stop" of Zantac and all medicines containing ranitidine, the generic treatment for stomach acid and ulcers.
The decision follows an announcement from the U.S. Food and Drug Administration that the drug contained a "probable" carcinogenic chemical in a type of nitrosamine called N-nitrosodimethylamine, or NDMA.
For now, U.S. health officials said patients can continue taking Zantac and similar heartburn medications, but prescription patients can consult their doctors if they want to switch to other treatments
The recalled drugs, which were manufactured in China, had higher levels of the NDMA chemical than U.S. health officials deemed acceptable.