More complexities have been added the treatment of hypertension making some of the drugs losartan, valsartan, irbesartan unsafe because they contain toxins which can cause cancer. Unfortunately the manufacturing process has altered in China, (possibly India) which is the chief source of the drug to USA and elsewhere, raising the levels of these toxins much higher. FDA officials believe that U.S. patients have been ingesting ARBs containing carcinogenic impurities for approximately 4 years; they estimate that for every 8000 patients taking the highest dose of an affected product for the full 4 years, one new cancer above the background incidence would be expected.
The Wall Street Journal reported that as many as 2 million patients had probably been exposed to the impurities, N-nitrosodimethylamine (NDMA) and N-nitroso-N-diethylamine (NDEA). Most recently, a third impurity, N-nitroso-N-methyl-4-aminobutyric acid (NMBA), has been identified in an ARB product, resulting in a new recall.
Although some products containing valsartan, irbesartan, or losartan remain commercially available in the United States, patients and the health care system have paid a steep price beyond the health concerns and anxiety arising from exposure to recalled products. One third of all FDA drug recalls issued since July 2018 have involved ARB-containing products, and together the recalls have affected one sixth of U.S. ARB manufacturers. Some unaffected manufacturers have increased valsartan prices twofold, threefold, or even more. The lack of selected ARB products has also placed pressure on the supply chain for non-recalled ARBs.
Though the FDA pinpoints a specific formulation and manufacturer in each recall, the dissemination of, and response to, FDA reports is uneven. Patients and clinicians may hear about recalls through the news media, social media, pharmacies, health care providers, or friends. Moreover, the public may hear about a recall of a “hypertension drug” but not know the specific product and manufacturer. Thus, recalls may trigger unnecessary concern among many people receiving antihypertensive therapy — and may be ignored by people who take ARBs for heart failure or chronic kidney disease. The burden of response has fallen to clinicians, pharmacies, and health care systems, most of which lack the infrastructure or resources to respond promptly to patients’ concerns.
So be aware of the problems that you are going to encounter. Be prepared to answer questions. Be prepared to change patients medications.
Hypertension Hot Potato — Anatomy of the Angiotensin-Receptor Blocker Recalls
J. Brian Byrd, M.D., M.S.C.I., Glenn M. Chertow, M.D., M.P.H., and Vivek Bhalla, M.D.March 13, 2019