Blood pressure medications seem to be plagued with recalls lately and this week is no different. Indeed, another angiotensin receptor blocker (ARB) blood pressure drug maker has announced a massive recall over concerns of potentially cancer causing impurities. This time, the recall comes from at least two pharmaceutical companies. Torrent Pharmaceuticals Limited is recalling more than 100 lots of hypertension-treating tablets and Camber Pharmaceuticals Inc has also voluntarily recalled 87 lots of the same.
The drugs involved with the recall are, once again, those containing Losartan potassium or a combination of Losartan potassium and Hydrocholothiazide. And also, once again, these products have been found to contain impurities that are similar to known human carcinogens: N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA).
But the FDA has recently found a third impurity that could also be potentially carcinogenic. This impurity is known as N-Nitroso-N-methyl-4-aminobutyric acid (NMBA), which is actually a known carcinogen in animals.
In a statement, FDA Commissioner Scott Gottlieb comments, “It’s important to underscore that, based on the FDA’s initial evaluation, the increased risk of cancer to patients with NMBA exposure appears to be the same for NDMA exposure but less than the risk from NDEA exposure. That said, any presence of such impurities in drug products is not acceptable. Over the past few months, the FDA has conducted a major investigation and has worked with drug companies to address the presence of impurities in these products.”
Gottlieb goes on to say, “Our ongoing effort has determined that the impurities may be generated by specific chemical reactions in the manufacturing process of the drug’s active pharmaceutical ingredients. FDA scientists have developed novel and sophisticated testing methods specifically designed to detect and measure [NDMA and NDEA] impurities in ARB medicines. Because of the potential for discovering other nitrosamine impurities, we are conducting an extensive organic chemistry analysis to develop novel testing methods to detect additional nitrosamine impurities, including NMBA.”
Indeed, the FDA has safeguards aimed at preventing drug contamination and it is expected that manufacturers will report impurities. Also, the agency regularly inspects factories that make drug products, but this is on a risk-prioritized basis. However, it is not always easy to find these impurities because you don’t always know what you are looking for.
As such, the agency continues regard what they find so they can improve the detection methods during these inspections. In the meantime, the FDA continues to instruct patients and pharmacists to trade the contaminated medications for pure ones.