On Thursday, the U.S. Food and Drug Administration (FDA) took an unusual step of allowing patients to use currently available medications even if they are tainted until the fresh stock of untainted pills is manufactured. The agency did so due to a shortage of certain commonly prescribed antihypertensive agents that have been recalled for containing carcinogens.
Since July 2018, pharmacies have pulled separate lots of angiotensin II receptor blockers (ARBs) from their shelves due to manufacturing impurities of cancer-causing compounds.
Valsartan, losartan and irbesartan, which belong to the ARB class of drugs, had been tainted by nitrosamines, posing a cancer risk.
The drug regulatory body has worked with several manufacturers to recall tainted high blood pressure pills while keeping pharmacies as well as patients informed. However, the resulting drug shortages led the FDA to adopt more safety standards and flexible quality.
For instance, last month, the FDA allowed certain manufacturers to temporarily distribute tainted losartan pills to overcome shortages. In addition, the agency approved a new type of generic valsartan (Diovan) to relieve shortages.
Dr. Scott Gottlieb, soon-to-be-ex FDA Commissioner, and Dr. Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research, said, “They have carefully evaluated safety data, weighed the risks and decided that it’s critical that patients have access to these drugs while impurity-free losartan is manufactured.”
They wrote, “Our scientists feel that this will not have a meaningful increased risk for cancer over the time it should take to get impurity-free losartan to market. We want to reassure patients that we strongly believe the risks, such as stroke, of abruptly discontinuing these important medicines far outweighs the low risk associated with continuing the medications with these impurities.”
The agency’s statement said, “Since the first nitrosamine impurity was discovered last summer, the FDA has identified 40 drugs that do not contain nitrosamine.”
It is expected that the number will only increase in next months, but meanwhile, the FDA recommends that patients should continue taking the available pills, even if they are tainted.
According to Maisha Kelly Freeman, a professor and director of Samford University’s Center, losartan was the #9 most dispensed drug in the U.S., while valsartan was #92 and irbesartan was #171.
The risk of patients developing cancer due to ARBs appears low. Freeman explained, “If 8,000 patients take a contaminated product over the course of four years, only one will develop the cancer. That’s the worst-case scenario if someone took the affected product each and every time they got it filled.”
The FDA also stated, “Even if they learn that their ARB medicine is recalled, patients should continue taking their pills until their doctor or pharmacist provides a different treatment option or safe replacement.” Dr. Gottlieb and Dr. Woodcock concluded, “We’ll continue to prioritize our investigation into this ongoing issue. This will remain an area of intense focus in the months ahead.” They said, “The FDA expects that manufacturers will replenish the supply of untainted blood pressure pills drugs in about six months.”