WASHINGTON -- U.S. health officials said Friday they are investigating low levels of a potentially dangerous contaminant in the popular heartburn medication Zantac and related generic drugs.
For now, the Food and Drug Administration said patients can continue taking their medications.
The agency said it has detected a "probable" cancer-causing chemical in the medications, which are sold as both prescription and over-the-counter treatments to treat stomach acid and ulcers.
FDA officials said the amount of the impurity barely exceeds levels found in common foods. But the same chemical has been linked to dozens of recalls of prescription blood pressure drugs in the past year. The FDA is still investigating that issue and last month sanctioned a manufacturing plant in India that makes some of the ingredients used in the medications.
Zantac maker Sanofi said in a statement it "takes patient safety seriously, and we are committed to working with the FDA."
The FDA is responsible for ensuring that U.S. medicines are manufactured in safe, sanitary conditions. But regulators have struggled for years to inspect the supply chain as pharmaceutical production has spread globally.
For decades the FDA focused its manufacturing inspections on U.S. factories. But over time, most companies have moved their manufacturing overseas to take advantage of cheaper labor and materials. Today, roughly 80% of the ingredients used in U.S. drugs are manufactured abroad, primarily in India and China, according to the Government Accountability Office.