The European Medicines Agency (EMA) is expanding its review of impurities in valsartan following the detection of very low levels of N-nitrosodiethylamine (NDEA) in another active substance, losartan, made by Hetero Labs in India.
As a result of the detection of this impurity by German authorities, the review will now include medicines containing four other ‘sartans’, namely candesartan, irbesartan, losartan and olmesartan.
Like valsartan, these active substances have a specific ring structure (tetrazole) whose synthesis could potentially lead to the formation of impurities such as NDEA. Other medicines of the class which do not have this ring are not included in the review.
Both NDEA and a related compound N-nitrosodimethylamine (NDMA) are classified as probable human carcinogens (substances that could cause cancer). How these impurities came to be present during the manufacture of sartans is yet to be fully established and is being evaluated in the ongoing review.
Based on the trace amounts of NDEA seen so far in one batch of losartan from Hetero Labs, there is no immediate risk to patients. Patients are therefore advised not to stop taking losartan or other sartan medicines without speaking to their doctor.
Further tests are required to determine the extent of the contamination and whether impurities are present in sartan medicines above levels that can be considered acceptable.
This review was started when unacceptable levels of NDMA were found in some valsartan medicines, which have now been recalled in the EU. Subsequently, NDEA was detected in some of the recalled valsartan products.
The extension of the review to other sartans is precautionary. EMA is working closely with national authorities, international partners and EDQM to gather data on these medicines as quickly as possible.
EMA will continue providing updates as more information becomes available and will take any necessary actions to protect patients’ health.