The U.S. Food and Drug Administration (FDA) has banned all imports of drugs and drug products from Zhejiang Huahai Pharmaceutical, which manufactured valsartan, a high blood pressure medication that had a possible carcinogenic impurity.

In July 2018, the FDA and European Medicines Agency (EMA) supported a voluntary recall of lots of the generic blood pressure drug valsartan after it was discovered that the drugs were tainted with N-nitrosodimethylamine, or NDMA, which is an impurity that is considered a possible carcinogen by the U.S. Environmental Protection Agency (EPA). NDMA can be unintentionally introduced into manufacturing through certain chemical reactions.

NDMA is an organic chemical is used to make liquid rocket fuel and a byproduct from manufacturing some pesticides and processing fish.

Valsartan is off patent and is used as a component of other generic medicines. The medicines included in the voluntary recall include valsartan from Major Pharmaceutical, Solco Healthcare, and Teva Pharmaceutical Industries, as well as valsartan/hydroclorothiazide from Solco and Teva. Not all versions of the drugs have been recalled, but the FDA keeps a regularly updated list of the drugs that have been impacted.

Since the recall, the FDA has been working with the affected companies to reduce the chances of such a recall occurring in future products, according to the agency.

The agency began testing the recalled products and the pills that have not been recalled for the substance after it learned that Zhejiang Huahai Pharmaceutical, found a second impurity, N-Nitrosodiethylamine, otherwise known as NDEA, in several batches of its valsartan active ingredient. NDEA is also a suspected human carcinogen.

Later, the FDA announced that three lots of the drugs made by Torrent Pharmaceuticals were found to be contaminated with the second impurity as well.

In August 2018, the FDA sent Zhejiang Huahai Pharmaceutical a Form 483 following a summer inspection of its Chuannan manufacturing facility in Linhai, China.

While a redacted version of the form did not disclose whether the observed issues directly concerned valsartan, the form did reaffirm concerns about the Chinese pharmaceutical company’s manufacturing processes. The issues highlighted in Form 483 included inadequacies in the change control system, issues with validating some control test procedures, and having quality systems that ensure active pharmaceutical ingredients (APIs) meet the FDA’s specifications.

In September 2018, the EMA reported that an inspection, in collaboration with the European Directorate for the Quality of Medicines & HealthCare, found that Zhejiang Huahai did not comply with good manufacturing practices in making valsartan at its Chuannnan facility.

The EMA issued a statement of noncompliance for the pharmaceutical company, and the site is no longer authorized to produce valsartan for EU medicines.

The FDA has noted that patients should look at the drug name and company name on the labels of their prescription bottles to determine whether their medicine has been recalled. If information is not on the bottle, patients should call their pharmacy for those details.

If you are worried your drug could be on the recall list, it is strongly recommended that you talk with your doctor or pharmacist before changing any routine with your medicine. Not all valsartan drugs are involved in the recall, which means your doctor may be able to switch you to a version of the drug produced by another company.