Further research
Manufacturers have been withdrawing their ranitidine products from the market since the reports of contamination surfaced last year. Several drugmakers, including Pfizer and Perrigo, have reported facing lawsuits connected with claims of cancer or increased cancer risk from ranitidine. In February 2020, a federal judicial panel opted to use a procedure, known as multidistrict litigation (MDL), to streamline the handling of these many cases. They were put before the U.S. District Court for the Southern District of Florida, labeled as In Re: Zantac (Ranitidine) NDMA Litigation.
A spokesman for FDA declined MDedge’s request for comment on Dr. Mohyuddin’s DDW presentation. He said the agency tends not to offer its views on work done by scientists outside of the FDA.
Valisure, an online pharmacy that runs quality checks on the medicines it dispenses, in September 2019 petitioned the FDA for a withdrawal of ranitidine due to concerns about NDMA. In its petition, Valisure reported finding notable levels of NDMA in ranitidine tablets, but not detecting it in testing of famotidine and several similar drugs. In an emailed statement, David Light, founder and CEO of Valisure, said the structure of Dr. Mohyuddin’s research limited its ability to detect cancer correlations because of the large and generalized study population.
“When comparing millions of people on medications which are both over-the-counter and prescription, any epidemiological impact will very likely be eclipsed by the sheer variations of exposure and a wide variety of confounding factors,” Mr. Light wrote.
There are a “vast number of variables that aren’t controlled for in such a massive and broadly defined cohort,” he added.
More focused and controlled studies will be needed to best evaluate NDMA and ranitidine, according to Mr. Light. “We are also investigating this issue with researchers at Memorial Sloan Kettering Cancer Center and plan to publish results soon,” he said.
Dr. Mohyuddin and Dr. Patel did not disclose financial conflicts in connection with ranitidine.
SOURCE: Mohyuddin N et al. DDW 2020. Abstract Tu1360.