April 5, 2019 -- The FDA on Thursday issued a list of 40 blood pressure medicines it found free of contamination with the chemical nitrosamine, an ongoing issue that has triggered several medication recalls since last summer.
The list is meant to help doctors make treatment decisions, but a cardiologist not involved in its creation says it should also spur patients to take action and be sure their doctors and pharmacies are not still giving them tainted medicines.
The drugs involved are medicines that lower blood pressure in a family of drugs known as ARBs (angiotensin II receptor blockers), which work by blocking the effect of angiotensin, a protein hormone that constricts blood vessels and raises pressure. The drugs are also used to treat heart failure and other problems.
Nitrosamines are environmental contaminants also found in water and foods; they are classified as substances that could cause cancer. In its ongoing review of the issues, the FDA says that "the maximum possible exposure to nitrosamines … in ARB medicines appears to be small," but their presence in drug products is not acceptable.
The problem came to light last July, when the FDA announced a voluntary recall of several medicines containing valsartan when the impurities were found.
The initial 40 medicines free of nitrosamine will be added to the “safe” list, the FDA says. The list is meant for health care professionals to review as they consider treatments. "We're also working with manufacturers to swiftly remove medications from the market if they contain a nitrosamine impurity at levels higher than the interim acceptable intake limits," the FDA statement says.
The removal of contaminated products has led to shortages, and the agency says it is working to help resolve those. One solution authorities propose is to temporarily allow specific lots of losartan, a drug also affected by the contamination, to continue to be distributed. "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," the statement says. The FDA predicts that will happen within 6 months.
While the list should help doctors and pharmacies focus on the vetted medicines, Guy L. Mintz, MD, director of cardiovascular health and lipidology at the Sandra Atlas Bass Heart Hospital in Manhasset, NY, is not confident that will happen.
"I don't have a lot of faith in the pharmacies to stock their shelves [only] with the medicines that have been vetted," he says. "It's nice that the FDA has done their due diligence and vetted 40 drugs," he says. But ''now you have to depend on the pharmacy."
Many patients use mail-order pharmacies, and the manufacturers on the medications can be switched without alerting them, he says.
He takes issue with the FDA saying people using the contaminated losartan could continue taking it until a contaminant-free supply of that drug is available. While the risk of cancer is deemed small, he says, many patients, especially those who have already survived a cancer, find that risk unacceptable.
Those patients might ask their doctors about switching to other types of ARBs, he says. "There are two other members of the ARB class that are actually longer-acting," he says. Those include telmisartan (Micardis) and olmesartan (Benicar). "To my knowledge, those two have never been contaminated."
His advice for those on blood pressure medicines: "Do not stop your medication. You could do more damage to yourself by stopping.''
For those on the contaminated drugs, he says: "Call your doctor. Make an appointment to discuss alternative medicine for your high blood pressure.''
"I would also tell patients to contact their pharmacies," he says, "to be sure they are on a brand vetted by the FDA and proven to be safe."