New shortages of blood pressure drugs in the U.S. are likely after a string of recent recalls linked to the discovery of a probable human carcinogen in the medications, the FDA warned Jan. 25.
The FDA learned last summer that some generic versions of a widely used medication to treat high blood pressure, called angiotensin II receptor blockers, contained nitrosamine impurities. The impurities, N-Nitrosodimethylamine and N-Nitrosodiethylamine, are likely carcinogenic.
The discovery initially prompted recalls of just a few drugs containing the impurity, but the list of recalls has grown.
The recalls affected the heart pressure medications valsartan, losartan and irbesartan. The most recent recall was announced this week.
"Currently, valsartan products are in shortage, and we know that other types of products may fall into shortage soon," the FDA said.
The impurities "may be generated when specific chemicals and reaction conditions are present in the manufacturing process" and "may also result from the reuse of materials, such as solvents," the FDA said.