China will tighten supervision of the sale and use of compound drugs that contain ephedrine, codeine, and diphenoxylate, according to the country's food and drug watchdog.

In an online statement by China's State Food and Drug Administration (SFDA) issued Wednesday, compound drugs that use each of the three specific ingredients should bear a standard digital code and be covered by China's digital monitoring network for drugs.

Starting on Jan. 1, 2012 the listed compound drugs without digital codes shall not be sold, the SFDA said, urging all related medicine manufacturers to register their products with the digital network by Dec. 31, 2011.

The SFDA said the step was part of its improved supervision efforts against misuse or overuse of such drugs.