Cause of deaths still in doubt after Sino-U.S. investigation on blood thinner

BEIJING, July 18 (Xinhua) -- The joint investigation by Chinese and U.S. drug authorities has not found out the exact cause of the deaths said to be related to a substance in blood thinner exported from China to the United States, said the Ministry of Health here Friday.

Experts from both countries had investigated the blood-thinner heparin products that caused adverse reactions since the U.S Food and Drug Administration (FDA) reported four deaths related to the drug in February, said Yan Jiangying, spokeswoman of the State Food and Drug Administration (SFDA), at a press conference.

Most serious adverse reactions were related to the products produced by the Baxter International, one of the major heparin producers in the United States, which bought raw substance from the U.S.-based Scientific Protein Laboratories (SPL).

The SPL owns a factory in Changzhou, east China's Jiangsu Province that supplies ingredients for heparin.

Both sides detected an ingredient called Hypersulphated Chondroitin Sulphate from the heparin products exported to the United States by SPL's Changzhou factory but could not confirm whether the ingredient was to blame for the adverse reactions, Yan said.

"Although we could not link the drug to the death cases, the SFDA has required Chinese producers to strictly check the content of Hypersulphated Chondroitin Sulphate and tightened quality control," she said.

In June, the FDA announced 149 deaths related to the use of heparin.

The SFDA had said in March that the Changzhou factory, a chemical plant but not a drugmaker, was not registered within the SFDA and its raw heparin was subjected to quality checks both by itself and SPL.