China's top food and drug watchdog has tightened its control over narcotic and psychotropic drugs in a bid to safeguard public health and social security, an official said Monday.

Yan Jiangyin, spokeswoman of the State Food and Drug Administration, said a homegrown nationwide monitoring network put into practice from September is monitoring in real time the production, supply, distribution, inventory and flow of these drugs.

Medicinal narcotic and psychotropic drugs - which include opium, heroin, morphine, marijuana and cocaine - are strictly controlled because of their potential for abuse.

"These drugs are a double-edged sword. If properly used they can assist in medical treatment to improve people's health," Gao Feng, director of the controlled drug inspection department of the SFDA, said.

Dolantin, a kind of narcotic drug, for instance, is usually prescribed to alleviate pain for cancer patients, Gao said.

It can be abused, he added, and this can lead to mental and physical problems, as well as damage public health and security.

Because of the monitoring network, the SFDA can now oversee the flow of narcotic and psychotropic drugs across the country, Yan said.

By linking drug supervision departments at different levels, drug producers and distributors nationwide, the network produces online, real time reports of production and sales data to the SFDA.

Since the beginning of this month, Yan said, the production, transportation and delivery of the drugs have been supervised by the SFDA.

"The building of the network doesn't stop there," Yan said. "It will further expand coverage to include more kinds of drugs."

In addition, medical institutions across the country will be covered by the network for more efficient supervision, by the end of 2010.

"It's a difficult task given that the country is so big, with so many hospitals," Gao said.

Currently, hospitals are the major channel through which narcotic and psychotropic drugs fall into the wrong hands, mostly drug addicts, Gao said.

A drug safety campaign, initiated by the SFDA, will be held from today to October 25 in some provinces, autonomous regions and municipalities across the country, Yan said at the conference.