Five Chinese pharmaceutical companies have begun a recall process to contain the potential health damage of a blood pressure medicine that contains valsartan produced by Zhejiang Huahai Pharmaceutical Co, China's food and drug safety authority said on Sunday.
The China Food and Drug Administration (CFDA) posted the progress of its intense monitoring after a July 6 public disclosure by Zhejiang Huahai Pharmaceutical Co over the impurity of the valsartan drug substance it manufactures.
The impurity could cause potential safety hazards and Zhejiang Huahai had already halted the supply of valsartan to domestic and foreign drug companies that are clients using the substance to make drugs.
The CFDA said it has been in close contact with the European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA) ever since Huahai's disclosure.
It has also conducted tests at all six domestic drugmakers except Huahai that produce valsartan in China, and that probe has found all of them are safe.
During an assessment to improve the manufacturing process, Huahai found that valsartan was tainted by a minute level of N-nitrosodimethylamine (NDMA), a genotoxic substance that could cause cancer, based on results from animal tests, according to a Huahai statement issued on July 7.
The recall work concerning the domestic market was completed on July 23.
Starting from Thursday, five domestic drugmakers that once use the Huahua substance were told to recall their products in the domestic market.
All the other valsartan drugs will not be affected by the recall, the CFDA said.
The EMA ordered a sales halt and recall while FDA advised that patients taking valsartan should not stop taking their prescribed drugs until the doctors found alternatives.
The CFDA recommended patients not to stop taking valsartan drugs as this would cause more health hazards and it said any decisions should be taken under doctor's advice.
Valsartan products are used to treat patients with high blood pressure.
The drug substance, manufactured by Huahai, was exported to the Americas, Europe, India and Russia.
