FDA tests indicated that the recalled lots of irbesartan contained N-Nitrosodiethylamine, or NDEA, a suspected human and animal carcinogen (cancer-causing agent) used in gasoline as a stabilizer for industry materials and as a lubricant additive. NDMA is also used to make liquid rocket fuel and is a byproduct of manufacturing certain pesticides and processing fish.
The recalled irbesartan will have “Westminster Pharmaceuticals” and “GSMS Inc.” on the labeling, FDA said.
Irbesartan is an angiotensin II receptor blocker, or ARB, that works by blocking a potent chemical in the blood called angiotensin, which causes muscles surrounding blood vessels to contract from binding with angiotensin II receptors. When Irbesartan binds, it narrows the vessels, which can cause high blood pressure (hypertension).
It is unclear at this point exactly what the cancer risk is with irbesartan; FDA believed that the risk was low with valsartan, another blood pressure drug recalled in August for the same potential contamination.
It estimated that if 8,000 people took the highest dose of valsartan (320 milligrams) containing NDMA for 4 years, there may be one additional case of cancer over the lifetimes of 8,000 patients. Many patients take a much lower dose of valsartan, and therefore their risks are theoretically much lower.
FDA said it will continue to test all products containing valsartan and similar medications for the presence of impurities.