(CNN) -- The US Food and Drug Administration is alerting patients of another recall of medicine used to treat high blood pressure, for a potential cancer risk due to contamination. This time, SciGen is recalling certain lots of irbesartan.
The recalled lot will have "Westminster Pharmaceuticals" and "GSMS Inc." on the label, according to the FDA list.
Another heart medicine, valsartan, has also been recalled recently due to contamination.
Irbesartan is an angiotensin II receptor blocker, or ARB. This is a drug that blocks a potent chemical in the blood called anigiotensin, which causes muscles surrounding blood vessels to contract from binding with angiotensin II receptors. When the chemical binds, it narrows the vessels, and that can cause high blood pressure.
FDA tests showed that the recalled lots of these drugs contained N-Nitrosodiethylamine or NDEA, a suspected human and animal carcinogen that is used in gasoline as a stabilizer for industry materials and as a lubricant additive, according to the National Institutes of Health.
This is the first non-valsartan drug product that the agency has found to contain the NDEA impurity.
Several pills that contain valsartan have been under a recall since July. The drugs were tainted with NDEA or NDMA, N-nitrosodimethylamine, an impurity that is also considered a possible carcinogen by the US Environmental Protection Agency.
NDMA is an organic chemical used to make liquid rocket fuel and a byproduct of manufacturing some pesticides and processing fish. It can be unintentionally introduced into manufacturing through certain chemical reactions.
The FDA is testing all ARBs for these impurities. It had to design a special test after it learned that some ingredients imported from one company in China, Zhejiang Huahai Pharmaceuticals, were tainted.
The FDA placed Zhejiang Huahai Pharmaceuticals on an import alert at the end of September, meaning all active pharmaceutical products and finished products made by the company will not be permitted to enter the United States. The FDA made that decision after its recent inspection of the facility.
Aurobindo, which makes the ingredient for ScieGen's irbesartan products, is recalling all unexpired lots of its irbesartan API supplied to the US market with NDEA. FDA and Aurobindo laboratory testing confirmed NDEA in certain lots of their irbesartan API.
Not all medicine containing valsartan or irbesartan is recalled. This recall affects about 1% of the irbesartan drug products in the US market, according to the FDA.
Talk with your doctor or pharmacist before changing any medicine. Because not all valsartan and irbesartan drugs are involved in the recall, you might be able to switch to a version by another company. The FDA keeps a second list of valsartan products that are not recalled.
If your drug is on the recall list, the FDA suggests taking it until your doctor or pharmacist provides a replacement.
It's unclear exactly what the cancer risk is if you take the contaminated valsartan or irbesartan pills; the FDA believed that the risk was low with the valsartan recall. It estimated that if 8,000 people took the highest dose of valsartan (320 milligrams) containing NDMA from these recalled batches daily for four years, there may be one additional case of cancer over the lifetimes of 8,000 people. Many patients take a much lower dose of valsartan, and therefore their risks are theoretically much lower.
The FDA said it will continue to test all products containing valsartan and similar drugs for the presence of impurities.