Causes for Contamination of Ranitidine Medicines

Dr Chia Shi-Lu asked the Minister for Health (a) whether the cause of the contamination of ranitidine medicines has been identified; (b) what measures have been put in place to advise patients who have the drug to stop using them; and (c) whether there will be any compensation for replacement of these medicines.

On 16 September 2019, the Health Sciences Authority (HSA) stopped the sale and supply of eight brands of ranitidine medicines at clinics, hospitals and pharmacies. HSA tested all rantidine medicines supplied in Singapore when it was alerted that a nitrosamine impurity, N-nitrosodimethylamine (NDMA), might be present in these products. The recall was initiated as a precautionary measure following the detection of trace amounts of NDMA above 96 ng per day. This is the internationally acceptable level of what was reasonably safe if a patient takes the affected medicine every day continuously for a lifetime of 70 years.

Ranitidine is used to reduce the production of acid in the stomach in conditions such as heartburn and gastric ulcers. As it is generally prescribed for short-term use of a few days to a few weeks, the potential additional cancer risk of nitrosamines is assessed to be very low (0.00003%). Nonetheless, HSA instituted a recall of the affected products to limit patients' further exposure to these products. Patients who are concerned about the use of the affected ranitidine medicines should contact their doctor.

Subsequently, Canada, Switzerland and the US undertook recalls between 17 and 24 September. All the recalls were also at the retail level. So, too, was the global recall by Sandoz on 17 September.

The root cause of nitrosamines in ranitidine medicines has yet to be established. HSA and international regulatory agencies are working with the companies supplying ranitidine medicines to identify the root causes of the contamination and to formulate the necessary measures to address the issue.

To ensure the quality of our medicines, companies that import new batches of ranitidine are required to test their products to ensure that they do not contain nitrosamine impurities above the internationally acceptable level before supplying them in Singapore.