BEIJING (AP) -- China said Monday it would ban a designer drug called U-47700 and three others, following U.S. pressure to do more to control synthetic opioids blamed for fast-rising overdose deaths in the United States.
In China, U-47700 has until now been a legal alternative to fentanyl and potent derivatives like carfentanil. Its usage has been growing among U.S. opioid addicts.
Last year, the U.S. Drug Enforcement Administration listed U-47700 in the category of the most dangerous drugs it regulates, saying it was associated with dozens of fatalities, mostly in New York and North Carolina. Some of the pills taken from Prince's estate after the musician's overdose death last year contained U-47700.
The DEA has long said that China is the top source country for synthetic opioids like fentanyl and its precursors, assertions Beijing has said lack firm evidence. Still, the two countries have deepened cooperation as the U.S. opioid epidemic intensifies.
Deng Ming, deputy director of the National Narcotics Control Commission, said that U-47700 and three other synthetic drugs - MT-45, PMMA, and 4,4'-DMAR - would be added to China's list of controlled substances as of July 1.
Yu Haibin, a division director at the Ministry of Public Security's Narcotics Control Bureau, said China was making "big efforts" to deal with drugs known as new psychoactive substances. These substances are made by modifying the chemical structures of controlled substances in order to get around the law, and China has now restricted 138 of them.
However, as soon as one substance is banned, chemists create slightly different and technically legal alternatives and then market them online.
"My feeling is that it's just like a race and I will never catch up with the criminals," Yu told a news conference. "Actually, we just want to make a breakthrough in dealing with this."
To counter the cat-and-mouse game, Yu said authorities had set up a system whereby information on new types of drugs gleaned during police investigations, customs clearances and medical treatment would be transferred to the national drug lab. An expert committee would then assess this information and send alert notices to relevant agencies in order to help speed up the control of new substances, he said.
Yu said suspects use the internet to communicate with customers and use the anonymized digital currency bitcoin to transfer money, and that authorities were working with internet companies to try to stop such trade and the advertising of drugs on websites.
To combat drugs being sent by post or express delivery service, authorities were carrying out real-name registration requirements and X-rays of parcels being delivered to "high-risk areas," he said.
Addressing the news conference, Justin Schoeman, Beijing-based country attache for the U.S. Drug Enforcement Administration, said: "I can tell you that when China controls a substance, (new psychoactive substances) or fentanyl-classed substance, it has a huge impact on seizures and availability in the U.S., so thank you very much.
"The controlling of substances in China certainly saves lives in the U.S.," he added.
He added that China's banning of additional substances means the U.S. and China can now carry out joint investigations on those chemicals, including the tracking of packages from the source through to the recipients in the U.S.
U-47700 is a synthetic opioid, a fast-proliferating class of drugs that have caused thousands of deaths in the United States. In 2015 alone, there were 9,580 deaths due to synthetic opioids other than methadone, accounting for almost a fifth of all drug overdose deaths.