Recently, both the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) recommended precautionary measures due to the presence of N-nitrosodimethylamine (NDMA) in medicines containing the drug ranitidine. NDMA is classified as a probable human carcinogen on the basis of animal studies. It is present in some foods and in water supplies but is not thought to be dangerous when ingested in very low levels, and there is no evidence that the impurity found in ranitidine has or will cause harm to patients.
Nevertheless, UK doctors are being told to stop prescribing several types of the heartburn medication as a precautionary measure. The same guidance also recommends that patients should keep taking their prescribed medicine. Confusing? Conflicting? Consequences?
Ranitidine products are used to reduce the production of stomach acid in patients with conditions such as heartburn and stomach ulcers. They are widely available over-the-counter and by prescription. First approved by the FDA in 1988, ranitidine was once the most prescribed medication in the world, and the first drug to ever reach 1 billion dollars in global sales in a single year. Needless to say, millions of patients all over the world have taken ranitidine or a similar drug at some point in their lives.
So what are patients to make of this finding, more than 30 years after it was first approved as ‘safe and effective’? What is perhaps most disturbing is that the discovery was not due to government oversight or a high profile lawsuit, but occurred in a tiny online US pharmacy conducting its own quality control, who then alerted the FDA to the potential issue.
The FDA firmly rejects suggestions that the drug supply is unsafe, but the issue legitimately raises many questions for patients. Patients should be able to trust that regulators stand by their safety labels and take steps to ensure long term quality control. When the system fails as seems to be the case for ranitidine, how are patients supported to ensure they have a transparent and sensible conversation about the implications and consequences? While it appears that the relative risk of cancer is low from this situation, the real risk is that patients will be left disillusioned, confused and their care potentially compromised.