The saga of potentially dangerous impurities in the U.S. drug supply continues. A suspected cancer-causing impurity that has been found in some blood pressure medicines has now shown up in Sanofi's Zantac and some over-the-counter heartburn drugs.
At this point, the FDA says that while N-nitrosodimethylamine (NDMA) has been discovered in these ranitidine medicines like Zantac, the risks are still unknown.
The FDA says it is working with regulators globally to determine the source of the tainted ingredient and has yet to determine whether the amount of the impurity in the drugs poses any kind of serious risk to consumers; the agency said it appears to be small.
“Although NDMA may cause harm in large amounts, the levels the FDA is finding in ranitidine from preliminary tests barely exceed amounts you might expect to find in common foods,” the FDA said.
The agency is not recommending patients quit using their medicines. Patients who take a prescription version should check with their doctor before quitting, the FDA said. Those who buy them over the counter might consider switching to an antacid that doesn’t contain ranitidine, which is an H2 (histamine-2), of which there are many.
In a statement, Sanofi pointed out that Zantac has been sold over the country for more than a decade and meets all of the FDA's requirements. But it said it is working the the FDA on the matter.
By Monday, the situation had generated its first lawsuit.
The FDA more than a year ago discovered the probable cancer-causing impurity NDMA was showing up in valsartan blood pressure meds made with an ingredient from China. It has been trying to get its arms around the problem since.
The discovery set off a global recall which has expanded exponentially as regulators found two other impurities. N-Nitroso-N-methyl-4-aminobutyric acid (NMBA) and NDEA, along with NDMA, can be created during sartan drug manufacturing under certain conditions. All are considered unsafe at certain levels. The recall was extended to some irbesartan and losartan drugs, causing shortages of losartan.