Angiotensin Receptor Blockers and the Risk of Cancer: Insights from Clinical Trials and Recent Drug Recalls.

Approximately 45.6% of adults in the USA have hypertension. ARB-containing medications are widely used in the USA, with tens of millions of prescriptions written yearly. Whether exposure to certain ARB drug products contributes to the development of cancer has been the topic of a series of publications. Nonetheless, ARBs' link to cancer, if any, remains inconclusive. Any mechanistic link between ARBs and cancer is poorly understood, with a variety of basic science studies suggesting that ARBs should exert a protective effect. Due to the presence of potentially carcinogenic nitrosamine impurities in certain ARB products, a series of large recalls in the USA and in countries around the world has occurred since 2018. These recalls have occurred in the context of two recent trends affecting antihypertensive drugs: nearly ubiquitous reliance on generic drugs and increased use of manufacturing facilities in China and India to supply the USA. Despite substantial efforts directed toward understanding whether ARBs have the potential to cause cancer, the available studies do not provide a consistent answer, and a causal link remains speculative. The principal conclusion must be that there is not a definitive signal for cancer associated with ARB exposure, although the possibility has not been fully excluded. The problem of nitrosamine impurities in certain ARB products (and some other drug products) is in need of further investigation, so that the risks can be mitigated by eliminating these impurities from the drug supply chain.